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20241018 NYS Route 29 Prime Station Lane Site Plan SWMR Report (compiled 7.12.24)
Prepared by: EP Land Services LLC 621 Columbia Street Ext. Cohoes, NY 12047 (518) 785-9000 Stormwater Management Report for (Part I) Station Park Subdivision City of Saratoga Springs Saratoga County, New York Prepared for Prime Companies 621 Columbia Street Ext. Cohoes NY 12047 July 12, 2024 July 2024 STORMWATER MANAGEMENT REPORT For STATION PARK SUBDIVISION SARATOGA SPRINGS, SARATOGA COUNTY, NEW YORK The overall Stormwater Management package consists of three reports: · The first report is the Stormwater Management Report. The Engineering report demonstrates through calculations that the proposed management technique will operate correctly and that the practice is designed in accordance with applicable standards. · The second report is the Stormwater Pollution Prevention Plan (SWPPP). The SWPPP details activities that are to occur during construction of the site. The SWPPP identifies the individuals that are responsible to prevent water quality violations and offsite degradation. The narrative report, along with the plans, show locations for temporary measures, such as silt fence, that should be used to protect the site until the site is stabilized. Sample weekly, monthly and quarterly reports have been included for documenting compliance with the SPDES permit. · The third report is the Post-Construction Maintenance Plan. The Maintenance Plan identifies to the Owner which activities can be anticipated to ensure that the stormwater management practice operated correctly. Routine maintenance activities have been identified and typical annual operating expenses have been presented. Table of Contents 1.0 EXECUTIVE SUMMARY ............................................................................................................ 1 1.1 Methodology for Designing Storm Water Management .................................................................... 1 2.0 SITE CONDITIONS .................................................................................................................... 2 2.1 Topography............................................................................................................................................ 2 2.2 Soils ........................................................................................................................................................ 2 2.3 Test Pits and Percolation Test ............................................................................................................. 2 3.0 PRE AND POST DEVELOPMENT PEAK DISCHARGE ............................................................ 3 3.1 Pre-Development Area Descriptions and Discharge Points ............................................................. 3 3.2 Post Development Area Descriptions and Discharge Points ........................................................... 3 3.3 Time of Concentration (TOC) ............................................................................................................... 4 3.4 Weighted Curve Number (CN).............................................................................................................. 4 3.5 Peak Discharges for Pre and Post Development Areas .................................................................... 4 3.6 Pre-Development vs Post Development Peak Discharges at Discharge Points ............................ 5 4.0 NYSDEC UNIFORM SIZING CRITERIA ..................................................................................... 6 4.1 Runoff Reduction Volume (RRv) ......................................................................................................... 6 4.2 Water Quality Volume (WQv) ............................................................................................................... 8 4.3 Channel Protection Volume (CPv) ....................................................................................................... 8 4.4 Overbank Flood Protection Volume .................................................................................................... 8 4.5 Extreme Flood Protection Volume ...................................................................................................... 8 4.6 Safe passage of the 100-Year Design Storm ...................................................................................... 8 5.0 PROPOSED WATER QUALITY AND QUANTITY CONTROLS ................................................. 9 5.1 Proposed Stormwater Management Strategy .................................................................................... 9 5.2 Water Quality Treatment, Pretreatment and Runoff Reduction Volume (Area #1A) ...................... 9 5.3 Water Quality Treatment, Pretreatment and Runoff Reduction Volume (Area #2) ......................... 9 5.4 Water Quality Treatment, Pretreatment and Runoff Reduction Volume (Area #3A) .................... 10 5.5 Water Quantity Using TR-55 Tabular Method For Post Development Area #1A .......................... 10 5.6 Water Quantity Using TR-55 Tabular Method For Post Development Area #2 ............................. 11 5.7 Water Quantity Using TR-55 Tabular Method For Post Development Area #3A .......................... 12 5.8 Combined Flows to Discharge Point #1, #2 and #3 ......................................................................... 13 July 2024 5.9 Water Quality Treatment Diversion (STMH#7) ................................................................................. 14 6.0 PROPOSED CONVEYANCE SYSTEM AND DISCHARGE POINT ......................................... 15 7.0 EXHIBITS ................................................................................................................................. 16 Exhibit A – Soils, Rainfall and CN Calculations ........................................................................................... 17 .1 24-Hour Rainfall Intensity Table ....................................................................................................... 17 .2 Pre-Development CN ........................................................................................................................ 17 .3 Post Development CN ...................................................................................................................... 17 .4 NRCS Soil Information and Gifford Engineering Results ................................................................. 17 Exhibit B – WQv and Pretreatment ................................................................................................................ 18 .1 WQv calculations .............................................................................................................................. 18 .2 Hydrodynamic Unit information ......................................................................................................... 18 .3 WQv Peak flows ................................................................................................................................ 18 Exhibit C – Hydrologic Model Simulation Using TR-55 Tabular Method .................................................... 19 .1 Routing Tables for the 1, 2, 10, 25, 50 and 100 year storms with Inflow and Outflow Hydrographs 19 Exhibit D – Drainage Calculations .................................................................................................................. 20 .1 Pipe Capacities and Expected Flows ............................................................................................... 20 Exhibit E – Maps ............................................................................................................................................... 21 .1 Project Location Map ........................................................................................................................ 21 .2 Soil Map (Figure 1) ........................................................................................................................... 21 .3 Pre-Development Watersheds (Figure 2) ......................................................................................... 21 .4 Post Development Watersheds (Figure 3)........................................................................................ 21 .5 Catch Basin Sub-Watershed Areas (Figure 4) ................................................................................. 21 B. Stormwater Pollution Prevention Plan (SWPPP) Table of Contents 1.0 OWNER AND CONTRACTOR’S/SUBCONTRACTOR’S CERTIFICATION ............................... 1 2.0 NYSDEC GUIDELINES FOR PREPARING A SWPPP .............................................................. 6 3.0 CONSTRUCTION EROSION CONTROL PRACTICES ............................................................ 17 4.0 CONSTRUCTION WASTE MANAGEMENT............................................................................. 18 5.0 SEQUENCE OF CONSTRUCTION .......................................................................................... 19 6.0 EROSION CONTROL MAINTENANCE DURING CONSTRUCTION ....................................... 20 7.0 GENERAL PERMIT (GP 0-20-001) INFORMATIONS .............................................................. 21 Exhibits ............................................................................................................................................................. 22 Exhibit F – Stormwater Pollution Prevention Plan (SWPPP) ....................................................................... 23 C. Post Construction Maintenance Plan Table of Contents 1.0 OPERATION AND MAINTENANCE INFORMATION ...................................................................... 1 2.0 DESIGN AND CONSTRUCTION INFORMATION ............................................................................ 2 3.0 MAINTENANCE AND INSPECTION RESPONSIBILITIES .............................................................. 3 4.0 FUNDING MECHANISM .................................................................................................................. 4 5.0 POST-CONSTRUCTION STORMWATER MANAGEMENT FACILITIES (PRACTICES) ................. 5 6.0 ATTACHMENTS TO MAINTENANCE PLAN ................................................................................... 8 Exhibits ............................................................................................................................................................... 9 Exhibit G – Post Construction Maintenance Information ............................................................................ 10 I:\ENGINEERING PROJECTS\PRIME COMPANIES\2022\2022-02-SARATOGA STATION\03-ADMIN\REPORTS\STORM REPORT\SWMR REPORT 6.30.24.DOCX Stormwater Management Report July 2024 Page 1 1.0 EXECUTIVE SUMMARY Prime Companies proposes to construct two multi-family buildings, townhouses and a hotel on parcels located at NYS Route 29 (between Washington Street and Station Lane) in the City of Saratoga Springs. The parcels total 17.6 acres and are comprised of tax parcels 165.2-70, 165-2-18 and 165-2-19. The proposed project will construct 344 multi-family apartment units within 2 buildings, 46 row houses and one 110 room hotel. As part of the project the parcel will be subdivided into thirteen (13) parcels. Currently, the site is undeveloped with woods covering most of the parcels. The proposed plan the project will be subject to NYSDEC SPDES Phase II requirements for water quality and quantity as the project will disturb greater than 1 acre. Approximately 17.0 acres will be disturbed for the development of the site. The proposed site improvements have been designed in accordance with the Stormwater Management Design Manual (SWDM) published by the New York State Department of Environmental Conservation (NYSDEC) The objective of controlling water quantity is to ensure that the peak rate of runoff leaving the site does not increase as result of site development. Enhanced stormwater regulations implemented in 2003 call for more stringent design standards when dealing with stormwater runoff on sites disturbing more than 1 acre of land. The “new” regulations are commonly referred to as “Phase II” guidelines. The proposed improvements for the project site meet or exceed water quantity, runoff reduction and water quality requirements as specified in the 2015 NYSDEC SWDM guidelines. The proposed management strategy consists of using a wet swale (O-2), Infiltration Basin (I-2) and underground infiltration arrays (I-4) to manage water quantity and address Water Quality (WQv) and Reduction Runoff (RRv) for the project site. Routine maintenance is a key component in the successful operation of the stormwater management practice. Provisions ensuring the upkeep are required and are submitted in the accompanying maintenance plan. The Maintenance Plan, Stormwater Pollution Prevention Plan (SWPPP) and draft Notice-of-Intent (NOI) Application have been completed for this site. The NOI is required to be submitted to NYSDEC in order to obtain a SPDES Phase II permit. Application to NYSDEC for coverage under the Phase II permit occurs prior to construction activities and after municipal site plan approvals are obtained. The following Stormwater Management Report quantitatively assesses the pre-development and post- development runoff conditions of the site. The report documents that the proposed improvements will meet the minimum requirements of water quality parameters as set forth in the NYSDEC guidelines. 1.1 Methodology for Designing Storm Water Management 1. Determine contributory watershed area(s) and subsequent sub-watersheds for proposed site according to site conditions. Design a pipe layout to convey stormwater to selected locations. 2. Evaluate pre and post development stormwater runoff conditions for various storm intensities, durations and frequencies of occurrences using USDA Technical Release 55 (TR-55) methodology. 3. Evaluate peak runoff and storage requirements for the NYSDEC specified 1, 2, 10, 25 and 100-year storm frequencies. Stormwater Management Report July 2024 Page 2 2.0 SITE CONDITIONS 2.1 Topography The general topography slopes from east to west. See Exhibit E.2 for the existing topography and the site is generally flat. Some of the project area stormwater runoff from will flow to the existing wetlands along Station Lane, while a majority of the site just infiltrates stormwater runoff due to the topography and sandy soil. Stormwater runoff from the site will eventually flow to Geser Brook to the north. 2.2 Soils The USDA Soil Survey was used to determine the existing soils within the project boundaries. Hydrologic soil groups were determined to analyze runoff volumes and flow rates. Soils found within the project and adjacent properties are as follows: DeA DeerField HSG A Sa Scarboro HSG A Wa Wareham HSG A WnB/WnC Windsor HSG A Hydrologic Soil Groups (HSG) A through D; ranging from well to poorly drained soils respectively. See Exhibit A.4 for further soil information. The information in Exhibit A.4 is depicted in Exhibit E.2, entitled “Soil Map” for soil delineation within the project site. 2.3 Test Pits and Percolation Test Contained within civil site plans there are multiple test pits and failing head test performed by Gifford Engineering. The test pits and percolation test were performed within the proposed stormwater management areas. Per the test pit results, the test pit went down 6 to 8 feet in depth from existing grade. The proposed bottom of infiltration systems or wet swale varies but upon the site location. The season high water elevation (SHGW) elevation varied throughout the site but in general from east to west. The SHGW elevation general went from elevation 319.0 to elevation 315 from east to west across the site. Per NYSDEC SWDM an infiltration basin or underground infiltration arrays are required to have 3-foot separation requirement between SHGW elevation and bottom of infiltration system. The table below summaries those results shown on C-2 of construction drawings. Percolation tests (falling head test in conformance with NYSDEC SWDM were performed next to the test pits. See Exhibit A.4 and construction drawings for results shown below. Stormwater Practice Test Pit # Ground Elevation Depth to Ground Water Ground Water Elevation Seasonal High Ground Water Elevation (SHGW) Bottom Elevation of Stormwater Practice Difference between SHGW and bottom of Practice (feet) Field Infiltration Rate (inches/hour) Wet Swale TP# 1 320.4 5.5 314.9 318.9 320 1.1 30 Infiltration Array #1 TP# 8 323.4 7.5 315.9 315.9 319 3.1 43,200 Infiltration Array #1 TP# 8A 323.4 7.5 315.9 315.9 319 3.1 43,200 Infiltration Basin #1 TP# 11 323.6 9 314.6 314.6 319 4.4 2,466 Infiltration Basin #1 TP# 10A 323.1 9 314.1 314.1 319 4.9 2,544 Stormwater Management Report July 2024 Page 3 3.0 PRE AND POST DEVELOPMENT PEAK DISCHARGE This section describes the stormwater analysis relative to the site, including the runoff generated within the limits of the site as well as contributing watershed to the discharge point. Analysis of upstream/downstream watershed to the receiving waters for this project site is not included in the computations for this report. The peak discharge rates represented in this report demonstrate only the expected peak flows from the delineated watersheds and do not take into account the overall watersheds. The non-delineated Pre and Post Development upstream/downstream watersheds are considered base flow and where the proposed site improvement will not have an effect on stormwater runoff. Therefore, the Pre and Post Development non-delineated upstream/downstream watershed will have the exact same stormwater runoff characteristics. 3.1 Pre-Development Area Descriptions and Discharge Points The Pre-Development stormwater system was analyzed by subdividing the watershed areas to estimate the runoff from each watershed area. The site was divided into three (3) areas, based on the discharge points. (Refer to Figure 2– “Pre-Development Watersheds” in Exhibit E.3) Pre-Development Area #1 has been delineated and stormwater runoff flows to the wetlands on the parcel located in the north portion of the site. The watershed is approximately 2.4 acres in size and contains woods. All stormwater runoff from this watershed will flow to the east in the roadside swale of Station Lane (Discharge Point #1). All stormwater runoff from this watershed will eventually flow to the Geyser Brook. Pre-Development Area #2 has been delineated and stormwater runoff flows to a low point on the site in which infiltration occurs (Discharge Point #2). The watershed is approximately 10.5 acres in size and contains woods, grass and impervious area. Pre-Development Area #3 has been delineated and stormwater runoff flows to the west (railroad tracks- Discharge Point #3). The watershed is approximately 8.5 acres in size and contains woods, grass, gravel and impervious areas. 3.2 Post Development Area Descriptions and Discharge Points The following section describes the post development stormwater system. The post development watershed has been subdivided in order to accurately estimate the runoff from the watershed and the effect of the proposed development. To analyze and compare the post development conditions, with the pre-development conditions, the watershed was divided into five (5) areas. (Refer to Figure 3 – “Post-Development Watersheds” in Exhibit E.4) Post Development Area #1 has been delineated and stormwater runoff flows to the wetlands on the parcel located in the north portion of the site. The watershed is approximately 1.3 acres in size and contains woods. All stormwater runoff from this watershed will flow to the east in the roadside swale of Station Lane (Discharge Point #1). All stormwater runoff from this watershed will eventually flow to the Geyser Brook. Post Development Area #1A is approximately 0.70 acres in size and contains grass and impervious areas from the proposed site improvements. The stormwater runoff will be collected by an on-site closed drainage system. The closed drainage system will direct stormwater runoff to a Wet- Swale (O-2). Stormwater runoff will then be discharged to the existing wetlands on site (Discharge Point #1). Post Development Area #2 is approximately 12.9 acres in size and contains woods, grass and impervious areas from the proposed site improvements. The stormwater runoff will be collected by an on-site closed drainage system. The closed drainage system will direct stormwater runoff to the underground Infiltration Array #1 (I-4). Stormwater runoff will then be discharged from the Underground Infiltration Array to the west (Discharge Point #3). Post Development Area #3 has been delineated and stormwater runoff flows to the west (railroad tracks- Discharge Point #3). The watershed is approximately 8.5 acres in size and contains woods, grass, and impervious areas. Post Development Area #3A is approximately 3.5 acres in size and contains grass and impervious areas from the proposed site improvements. The stormwater runoff will be collected by an on-site closed drainage system. The Stormwater Management Report July 2024 Page 4 closed drainage system will direct stormwater runoff to the Infiltration Basin #1 (I-2). Stormwater runoff will then be discharged from the Infiltration Basin to the west (Discharge Point #3). 3.3 Time of Concentration (TOC) Times of Concentration (TOC) paths were determined for Pre and Post Development subareas by using the methodology described in National Resource Conservation Service’s TR-55 manual. Sheet flow never exceeded 150 feet over natural undisturbed terrain for Pre-Development and 100 feet for Post Development per NYSDEC standards over disturbed areas. A Manning’s n=0.40 was used for Pre and Post development areas that sheet flowed across wooded areas. Manning’s n=0.24 for areas in which there was sheet flow across lawns or a Manning’s N value of 0.011 across pavement. Channel flow time for existing swales were estimated based on a 1-foot depth along with contours from the base map to determine cross sectional area and wetted perimeter. Channel flow time through proposed/existing piping was based on a 12” SICPP, flowing full with a Manning’s n=0.012. Calculations for the TOC paths can be found in Exhibit C. 3.4 Weighted Curve Number (CN) Within each watershed area, cover type and hydrologic condition are compared to the Hydrologic Soil Group classification to derive a runoff curve number. Subsequently, a weighted average, or composite runoff curve number (CN) is determined. Runoff curve number supporting calculations for pre-development and post- development scenarios are presented in Exhibit A.2 and A.3. 3.5 Peak Discharges for Pre and Post Development Areas The stormwater analysis was performed using Hydraflow Hydrographs software developed by Intellisolve®. The software uses the Soil Conservation Service (SCS), now known as (NRCS) National Resources Conservation Service, for both pre and post development areas/watersheds are shown in the following tables. Note: the peak discharges for both pre and post development were based on TOC, runoff (Q), Weighted Curve Number (CN) and other factors. Table-1 Pre-Development Peak Discharge Watershed 1-Year Peak Flow (cfs) 2-Year Peak Flow (cfs) 10-Year Peak Flow (cfs) 25-Year Peak Flow (cfs) 50-Year Peak Flow (cfs) 100- Year Peak Flow (cfs) CN Area (Acres) TOC (Min.) Pre Area #1 0.000 0.000 0.000 0.000 0.007 0.023 30 2.415 29.30 Pre Area #2 0.000 0.000 0.000 0.003 0.044 0.139 31 10.554 49.40 Pre Area #3 0.000 0.000 0.000 0.035 0.115 0.485 35 8.479 30.20 Table-2 Post Development Peak Discharge (Unattenuated) Watershed 1-Year Peak Flow (cfs) 2-Year Peak Flow (cfs) 10-Year Peak Flow (cfs) 25-Year Peak Flow (cfs) 50-Year Peak Flow (cfs) 100- Year Peak Flow (cfs) CN Area (Acres) TOC (Min.) Post Area #1 0.000 0.000 0.000 0.000 0.006 0.018 31 1.337 28.60 Post Area #1A 0.575 0.848 1.742 2.480 3.200 4.074 75 0.705 6.00 Post Area #2 8.320 11.68 22.50 31.32 39.65 49.56 80 12.898 24.40 Post Area #3 0.000 0.000 0.006 0.029 0.120 0.421 38 3.008 30.20 Post Area #3A 3.156 4.569 9.168 12.94 16.64 21.08 76 3.551 6.00 Stormwater Management Report July 2024 Page 5 * Post Development watersheds 1A and #3A were assigned a Time of Concentration of 6.0 minutes (minimum value) to determine the worst-case peak runoff conditions for these watersheds. 3.6 Pre-Development vs Post Development Peak Discharges at Discharge Points Post Development Areas #1, and #1A have a combined peak flow rate greater than Pre-Development Area #1 peak rate to discharge point #1 if a stormwater detention facility is not constructed. See section 5.0 of this report for water quantity mitigation required per NYSDEC SWDM. Post Development Areas #2 have a peak flow rate greater than Pre-Development Area #1 peak rate to discharge point #2 if a stormwater detention facility is not constructed. See section 5.0 of this report for water quantity mitigation required per NYSDEC SWDM. Post Development Areas #3, and #3A have a combined peak flow rate greater than Pre-Development Area #3 peak rate to discharge point #3 if a stormwater detention facility is not constructed. See section 5.0 of this report for water quantity mitigation required per NYSDEC SWDM. Stormwater Management Report July 2024 Page 6 4.0 NYSDEC UNIFORM SIZING CRITERIA The Environmental Protection Agency and New York State Department of Environmental Conservation have placed a greater emphasis on ensuring that water quality standards are maintained both onsite as well as downstream of the development. Maintaining water quality involves the removal or reduction of pollutants including suspended solids, phosphates, nitrates and other chemicals generated by development. The new water quality standards expand upon the peak flow attenuation concept to include parameters designed to protect downstream channels from stream bank erosion and flooding. NYSDEC assumes that, by default, the proposed stormwater management practice meets water quality objectives if the proposed practice is designed in accordance with the List of Acceptable Stormwater Management Practices set forth in the NYS Stormwater Management Design Manual (SMDM, page 4-3). The proposed strategy consists of utilizing a closed drainage system that directs the runoff towards Infiltration Systems or Wet Swale to address water quantity. All pretreatment for water quality will be done by a hydrodynamic unit before the stormwater runoff enters the Infiltration Systems or Wet Swale. The Infiltration Systems and Wet Swale will treat water quality volume and mitigate stormwater runoff volume associated with the development of the site. The stormwater analysis was performed using Hydraflow Hydrographs software developed by Intellisolve®. The software uses the Soil Conservation Service (SCS), now known as (NRCS) National Resources Conservation Service, hydrologic methods to compute the 24-hour precipitation event. The runoff curve numbers, and time of concentrations were computed using the NRCS TR-55 tabular methodology as described in Section 3.0 of this report. The 24-hour rainfall amounts for City of Saratoga Springs are documented in Exhibit A.1. 4.1 Runoff Reduction Volume (RRv) Implementation of green infrastructure practices aids in the reduction of runoff by proactively reducing runoff volume, peak flow, and flow duration. It promotes infiltration and evapotranspiration to improve groundwater recharge, and also relieves pollutants for the “end of pipe” stormwater treatment practice. The green infrastructure techniques listed below are pre-approved methods that the NYSDEC has deemed acceptable to be used towards the planning of development projects, and runoff reduction. Some standard SMPs may also be used instead of the factors below. Table-3 Runoff Reduction Techniques Group Practice Implementation/Justification Preservation of Natural Resources Preservation of Undisturbed Areas Areas were maintained as much as possible. Preservation of Buffers None presently exist on the site. Reduction of Clearing and Grading Clearing of site per zoning coding Locating Development in Less Sensitive Areas None presently exist on the site. Open Space Design The is per zoning code. Soil Restoration Soil restoration is provided for this project. See Construction Drawings for notes indicating this to be done. Reduction of Impervious Cover Roadway Reduction Roadway/accessway cross sections are minimal while maintaining Fire Code compliance and City code requirements Sidewalk Reduction Sidewalk widths are based on ADA compliance and good engineering practice. Driveway Reduction Joint driveways are proposed. Cul-de-sac Reduction Cul-de-sacs have been avoided at this project. Stormwater Management Report July 2024 Page 7 Building Footprint Reduction The height of building was based upon building code. Parking Reduction Parking area and turn aisle are design to City standards Runoff Reduction Techniques Conservation of natural areas Maintaining wetland buffer for project site. Sheetflow to riparian buffers or filter strips None presently exist on the site. Vegetated open swale Project site is not physically large enough to satisfy the design requirements set forth in the SWDM. Tree planting/tree box Landscaping along both roads that front property and within the site is proposed. Disconnection of rooftop runoff Project site does not allow enough space for dedicated filter strip area Stream daylighting for redevelopment projects None presently exist on the site. Rain garden Per Chapter 5 of NYSDEC SWDM page 5-79 states “rain garden cannot be used to treat parking lot or roadway runoff”. Green roof The architect has reviewed the option of installing a green roof, and has determined it was not feasible for this site. Stormwater Planter Planters is not conducive for this site because the maximum allowable area is 15,000 sf and the proposed building footprint is minimally 20,000 sf, thus planters are not an option per NYSDEC for this site. Rain tank/Cistern Practice is not being proposed as the proposed site does not have a lot of grass to water with cistern volume. Porous Pavement Porous pavement requires soils to be A, B or C to function properly per NYSDEC SWDM Chapter 5 page 5-116. Porous pavement was not selected for the project do to maintenance, cold weather climate and meeting City standards for roadways. The RRv is the minimum volume of runoff that is to be removed from the runoff volume that is sent to the “end of pipe” treatment practice by utilizing infiltration, evaporation, recycling, recharging, etc. The intent of implementing the green infrastructure techniques is to redistribute the WQv prior to runoff being collected by the proposed stormwater drainage system. As it is often difficult to remove the whole WQv, the minimum volume required is set as RRv. The remaining volume that is not treated (WQv – RRv as necessary) will then be treated at the “end of pipe” treatment system. RRv(acre-feet) = [(P)(Rv*)(Ai)] /12 Where: Ai=(S)(Aic) =impervious cover targeted for runoff reduction (Aic)=Total area of new impervious cover Rv* = 0.05+0.009(I) where I is 100% impervious S=Hydrologic Soil Group (HSG) Specific Reduction Factor (S) HSG A = 0.55 HSG B = 0.40 HSG C = 0.30 HSG D = 0.20 Stormwater Management Report July 2024 Page 8 Based upon calculations in Exhibit B.2 the following was determined: Minimum RRv= 27,605 cf Project achieves= 49,270 cf of RRv on the site. There is a 96% reduction in RRv as infiltration is being proposed for most of the site. 4.2 Water Quality Volume (WQv) The Water Quality Volume is designed to improve water quality sizing to capture and treat 90% of the average annual stormwater runoff volume. The proposed stormwater management strategy for this project is sized to accommodate the Water Quality Volume. The WQv was determined to be 51,130 cf for Post Development Area #1A, #2 and #3A for the project. The Water Quantity Area was based upon proposed parking areas, proposed building areas and sidewalk within Post Area #1A, #2 and #3A watersheds. See Exhibit B.1 for calculations. 4.3 Channel Protection Volume (CPv) The channel protection storage volume requirements are designed to protect downstream channels from erosion. This goal is accomplished by providing 24-hour extended detention of the one-year, 24-hour rainfall storm event. This volume is held over a 24 hour period; controlled by a discharge rate (volume/24 hours). As all stormwater is infiltrated for this project and no discharge form the project site CPv is not applicable for this site. 4.4 Overbank Flood Protection Volume The overbank flood protection volume requirements are incorporated to prevent an increase in the frequency of flooding and magnitude of out-of-bank flooding downstream of the management practice. Overbank control requires storage to attenuate the post-development 10-year, storm, and reduce the 24-hour peak discharge rate to the pre-development rates. 4.5 Extreme Flood Protection Volume The intent of the extreme flood protection volume is to a) prevent the increased risk of flood damage from large storm events, b) maintain the boundaries of the pre-development 100-year floodplain, and c) protect the physical integrity of the stormwater management practices. Extreme flood protection control requires storage to attenuate the post-development 100-year, 24-hour peak discharge rate to the pre-development rates. The 100-year attenuated storm event is further discussed in Section “5.0 Proposed Water Quality and Quantity Controls project. 4.6 Safe passage of the 100-Year Design Storm The physical integrity of the stormwater management practice must be maintained. The outlet structure(s) and emergency spillways must be designed to accommodate the 100-year design storm. Used in conjunction with the stage-storage relationship, the safe passage of the 100-year design storm reveals the maximum water surface elevation anticipated for the management practice. The 100-year storm event is further discussed in Section “5.0 Proposed Water Quality and Quantity Controls”. Stormwater Management Report July 2024 Page 9 5.0 PROPOSED WATER QUALITY AND QUANTITY CONTROLS 5.1 Proposed Stormwater Management Strategy Stormwater runoff will be collected by an on-site closed drainage system that directs the runoff towards stormwater practices. The stormwater runoff will be directed towards either 1. Underground Infiltration Array #1 2. Infiltration Basin #1 3. Wet Swale The stormwater is to be “treated” by the stormwater water practices on the project site and will be used to manage stormwater runoff (water quantity) for the project. The stormwater analysis was performed using Hydraflow Hydrographs software developed by Intellisolve®. The software uses the Soil Conservation Service (SCS), now known as (NRCS) National Resources Conservation Service, hydrologic methods to compute the 24-hour precipitation event. The runoff curve numbers, and time of concentrations were computed using the NRCS TR-55 tabular methodology as described in Section 3.0 of this report. The 24-hour rainfall amounts for City of Saratoga Springs are documented in Exhibit A.1. The hydrograph model is set up to simulate Pre-Development Areas and Post-Development to all Discharge Points. It is the goal of the hydraulic model to demonstrate the water surface elevation within the proposed stormwater practices and the net increase in peak discharge rates occur between pre-development and post- development conditions for the 1, 2, 10, 25, 50 and 100-year storm events. 5.2 Water Quality Treatment, Pretreatment and Runoff Reduction Volume (Area #1A) Post Development Area #1A watershed has been designed in accordance with NYSDEC Phase II Management Guidelines with respect to Water Quality requirements. The water quality volume (WQv) was determined to be 1,860 cf and a wet swale (O-2) is proposed to treat the water quality requirements of this watershed. The pretreatment volume of 10% of 1,860 cf must be achieved before stormwater runoff is allowed to flow into the wet swale practice. Using the SWDM, a WQv of 1,860 cf (see Exhibit B.1) equates to a WQv peak flow 0.80 cfs (See Exhibit B.3). The proposed hydrodynamic unit will be model CDS2020 (WQv#1 noted on plans) by Contech which can treat a WQv rate up to 1.1 cfs. The proposed wet swale (O-2) will only treat the WQv for this watershed and no RRv reduction is achieved per the SWDM for this practice. A wet swale was selected for this location as the seasonal high ground water (SHGW) elevation is 1.1 feet below the bottom of the practice. Even though the water table is 5 feet below the bottom of this practice, by default, due to the elevation of the SHGW, this practice is defined by SWDM as a wet swale for treatment of stormwater runoff. 5.3 Water Quality Treatment, Pretreatment and Runoff Reduction Volume (Area #2) Post Development Area #2 watershed has been designed in accordance with NYSDEC Phase II Management Guidelines with respect to Water Quality requirements. Post Development Area #2 stormwater runoff will be collected by a closed drainage system and will be sent to an Underground Infiltration Array #1 (I-4). Using the SWDM, the WQv was determined to be 40,075 cf and this calculation can be found in Exhibit B.1. For an infiltration system, 100% of WQv must be pretreated before it enters the Infiltration basin as a result of the percolation rate being faster than 5.0 inch/hour. As there is not enough space for a traditional forebay, a hydrodynamic unit will be used as a pretreatment device for this watershed. Stormwater Manhole #7 (STMH#7) will send stormwater to a hydrodynamic unit (WQv#2) before stormwater runoff is allowed to flow into the Underground Infiltration Array #1. Using the SWDM a WQv of 40,075 cf equates to a WQv peak flow 13.80 cfs (See Exhibit B.3). The proposed hydrodynamic unit will be model CDS5653-D by Contech which can treat a WQv rate up to 14.0 cfs. As the hydrodynamic unit (WQv#2) needs to bypass flow during large storm events, STMH #7, has been designed to ensure WQv volume flows to the WQv#2 and larger storm events are sent directly to the underground arrays. An 18 pipe from STMH #7 to WQv#2 at an invert elevation of 319.50 will send up to 15.36 cfs to the hydrodynamic unit. All other stormwater flow is transported by a 24”x38” arch pipe at an elevation of 321.25 that directs stormwater runoff directly to the Infiltration Array. Stormwater Management Report July 2024 Page 10 The Infiltration Array #1 will achieve 100% WQv treatment and 100% RRv treatment for this watershed as the stormwater management practice infiltrates up to the 100-year storm event, thus meeting NYSDEC SWDM requirements. 5.4 Water Quality Treatment, Pretreatment and Runoff Reduction Volume (Area #3A) Post Development Area #3A watershed has been designed in accordance with NYSDEC Phase II Management Guidelines with respect to Water Quality requirements. Stormwater from Post Development Area #3A will be collected by a closed drainage system and will be sent to an Infiltration Basin #1 (I-2). Using the SWDM, the WQv was determined to be 9,194 cf this calculation can be found in Exhibit B.1. For an infiltration system, 100% of WQv must be pretreated before it enters the Infiltration basin as a result of the percolation rate being faster than 5.0 inch/hour. As there is not enough space for a traditional forebay, a hydrodynamic unit will be used as a pretreatment device for this project. Catch Basin #48 (CB#48) will send stormwater to a hydrodynamic unit (WQv#3) before stormwater runoff is allowed to flow into the Infiltration Basin #1. Using the SWDM, the WQv of 9,194 cf (see Exhibit B.1) equates to a WQv peak flow 3.96 cfs (Exhibit B.3). The proposed hydrodynamic unit will be model 4030 by Contech which can treat a WQv rate up to 4.5 cfs. The Infiltration Array #1 will achieve 100% WQv treatment and 100% RRv treatment for this watershed as the stormwater management practice infiltrates up to the 100-year storm event, thus meeting NYSDEC SWDM requirements. 5.5 Water Quantity Using TR-55 Tabular Method For Post Development Area #1A Under the proposed condition stormwater runoff from Post Development Areas #1 and #1A will exceed Pre- Development Areas #1 peak runoff rates to discharge point #1 if a detention facility was not constructed. To manage the increase in stormwater runoff volume associated with the proposed site improvements, in Post Development Area #1A delineated watershed, a wet swale will be installed. The wet swale will attenuate the increased stormwater runoff from the development of the site. Hydraflow Hydrographs software was used to develop a hydraulic model of the proposed wet swale in Post Development Area #1A delineated watershed. Hydraflow Hydrographs software was used to calculate the rate of infiltration and flow rate from the emergency overflow weir from this practice. While NYSDEC SWDM does not allow RRv credit for infiltration in a wet swale as the SHGW elevation does not meet the 3-foot separation requirement, the existing soil does allow for infiltration within the practice based upon result of test pits/infiltration test results The model demonstrates that the wet-swale will store up to the 100-year storm from the stormwater runoff volume associated with Post Development Area #1A delineated watershed. The hydraulic modeling was simulated for the 1, 2, 10, 25, 50 and 100-year storm events. See Exhibit C for model information and design. To obtain the results in Table 4, inflow (hydrograph #5 labeled “Post #1A” in Hydraflow Hydrographs software model) vs. outflow (hydrograph 15 labeled “Route Wet Swale #1” in Hydraflow Hydrographs software model) hydrographs and routing tables were calculated for the proposed stormwater system and the results are as follows: Table-4 Post Flow from Wet Swale System 1-Year Flow (cfs) 2-Year Flow (cfs) 10-Year Flow (cfs) 25-Year Flow (cfs) 50-Year Flow (cfs) 100-Year Flow (cfs) Post Development Area #1A (Inflow) 0.575 0.848 1.742 2.480 3.200 4.074 Max. Water Surface Elevation (WSEL) 320.18 320.27 320.62 320.91 321.12 321.36 Discharge from Wet Swale (Ouflow) 0.00 0.00 0.00 0.00 0.00 0.00 To obtain the result in Table 4 from the proposed wet swale labeled as “Wet Swale #1” in the software model, a weir (emergency spillway) “WrA” at elevation 321.50 and infiltration rate of 20 inches/hour was used to stimulate storm events in the Hydraflow Hydrographs software model. Stormwater Management Report July 2024 Page 11 The 100-year WSEL has been determined to be 321.36 or there is 0.64 feet of freeboard within the practice as the top of swale is proposed is at elevation 322.00. There will be a maximum depth of 1.36 feet or 16 inches which is less than the maximum allowable of 18 inches per SWDM. Infiltration was utilized for this practice in the hydraulic model based upon existing test pits/infiltration test results. This area was determined to have a percolation rate of 30 inches/per hour at elevation 319.00 or 12-inches below the proposed bottom of wet swale. The model uses a percolation rate of 20 inches/per hour or a safety factor of 1.5 was used in the calculations. Stormwater Practice Test Pit # Ground Elevation Depth to Ground Water Ground Water Elevation Seasonal High Ground Water Elevation (SHGW) Bottom Elevation of Stormwater Practice Difference between SHGW and bottom of Practice (feet) Field Infiltration Rate (in/hr) Design Infiltration Rate (in/hr) Wet Swale TP# 1 320.4 5.5 314.9 318.9 320.0 1.1 30 20 5.6 Water Quantity Using TR-55 Tabular Method For Post Development Area #2 Under the proposed condition stormwater runoff from Post Development Areas #2 will exceed Pre-Development Areas #2 peak runoff rates to discharge point #2 if a detention facility was not constructed. To manage the increase in stormwater runoff volume associated with the proposed site improvements, in Post Development Area #2 delineated watershed, an underground infiltration array will be installed. The underground infiltration array will attenuate the increased stormwater runoff (water quantity) from the development of the site and also addresses WQv/RRV water quality requirements. The underground infiltration array (Infiltration Array #1) will be comprised of four (4) sticks of 36-inch perforated pipe, 180 linear feet long with void stone. Void stone was assigned 20% void ratio in design calculations. Hydraflow Hydrographs software was used to develop a hydraulic model of the infiltration array in Post Development Area #2 delineated watershed. The model demonstrates that the infiltration array will store up to the 100-year storm from the stormwater runoff volume associated with Post Development Area #2 delineated watershed. The hydraulic modeling was simulated for the 1, 2, 10, 25, 50 and 100-year storm events. See Exhibit C for model information and design. To obtain the results in Table 5, inflow (hydrograph #6 labeled “Post #2” in Hydraflow Hydrographs software model) vs. outflow (hydrograph 13 labeled “Route Array #1” in Hydraflow Hydrographs software model) hydrographs and routing tables were calculated for the proposed stormwater system and the results are as follows: Table-5 Post Flow from Underground Detention Array Systems 1-Year Flow (cfs) 2-Year Flow (cfs) 10-Year Flow (cfs) 25-Year Flow (cfs) 50-Year Flow (cfs) 100-Year Flow (cfs) Post Development Area #2 (Inflow) 8.320 11.68 22.50 31.32 39.65 49.56 Water Surface Elevation (WSEL-Array #1) 319.02 319.02 319.04 319.06 319.07 319.07 Discharge from Arrays (Outflow) 0.00 0.00 0.00 0.00 0.00 0.00 To obtain the result in Table 5 from the proposed Underground Infiltration Array labeled as “Infiltration Array #1” in the software model, an emergency overflow pipe “CLvA” at elevation 323.50 and infiltration rate of 200 inches/hour was used to stimulate storm events in the Hydraflow Hydrographs software model. The 100-year water Surface Elevation (WSEL) has been determined to elevation 319.07 within Infiltration Array #1. The top storage elevation of Infiltration Array #1 is elevation 324.00. This allows for approximately 4.53 feet of additional storage within the arrays. Stormwater Management Report July 2024 Page 12 Infiltration was utilized for this practice in the hydraulic model based upon existing test pits/infiltration test results. This area was determined to have a percolation rate greater than 40,000 inches/per hour at elevation 318.40 or 6- inches below the proposed bottom of array. The model uses a percolation rate of 200 inches/per hour or a safety factor over 200 was used in the calculations. Stormwater Practice Test Pit # Ground Elevation Depth to Ground Water Ground Water Elevation Seasonal High Ground Water Elevation (SHGW) Bottom Elevation of Stormwater Practice Difference between SHGW and bottom of Practice (feet) Field Infiltration Rate (in/hr) Design Infiltration Rate (in/hr) Infiltration Array #1 TP# 8 323.4 7.5 315.9 315.9 319.0 3.1 43,200 200 Infiltration Array #1 TP# 8A 323.4 7.5 315.9 315.9 319.0 3.1 43,200 200 The potential storage volume in the catch basins and closed drainage system was also not accounted for when the Hydraflow Hydrographs software model was developed. Between not including the closed drainage potential storage volume and having a safety factor on the infiltration rate, the WSEL in Table #5 is conversative or higher than what will actually occur. 5.7 Water Quantity Using TR-55 Tabular Method For Post Development Area #3A Under the proposed condition stormwater runoff from Post Development Areas #3 and #3A will exceed Pre- Development Areas #3 peak runoff rates to discharge point #3 if a detention facility was not constructed. To manage the increase in stormwater runoff volume associated with the proposed site improvements, in Post Development Area #3A delineated watershed, an Infiltration Basin will be installed. The Infiltration Basin will attenuate the increased stormwater runoff (water quantity) from the development of the site and addresses WQv/RRV water quality requirements. Hydraflow Hydrographs software was used to develop a hydraulic model of the proposed detention basin in Post Development Area #3A delineated watershed. The model demonstrates that the Infiltration Basin #1 will store up to the 100-year storm from the stormwater runoff volume associated with Post Development Area #3A delineated watershed. The hydraulic modeling was simulated for the 1, 2, 10, 25, 50 and 100-year storm events. See Exhibit C for model information and design. To obtain the results in Table 6, inflow (hydrograph #5 labeled “Post #3A” in Hydraflow Hydrographs software model) vs. outflow (hydrograph 14 labeled “Route Basin #1” in Hydraflow Hydrographs software model) hydrographs and routing tables were calculated for the proposed stormwater system and the results are as follows: Table-6 Post Flow from Infiltration Basin #1 1-Year Flow (cfs) 2-Year Flow (cfs) 10-Year Flow (cfs) 25-Year Flow (cfs) 50-Year Flow (cfs) 100-Year Flow (cfs) Post Development Area #3A (Inflow) 3.156 4.569 9.168 12.94 16.64 21.08 Max. Water Surface Elevation (WSEL) 319.35 319.51 320.03 320.51 321.03 321.52 Discharge from Basin (Outflow) 0.00 0.00 0.00 0.00 0.00 0.00 To obtain the result in Table 6 from the proposed Infiltration Basin labeled as “Basin #1” in the software model, a weir (emergency spillway) “WrA” at elevation 324.00 and infiltration rate of 200 inches/hour was used to stimulate storm events in the Hydraflow Hydrographs software model. The 100-year water Surface Elevation (WSEL) has been determined to elevation 321.52 within Infiltration Basin #1. This allows for approximately 3.48 feet of additional storage within the basin as the top of basin is proposed is Stormwater Management Report July 2024 Page 13 at elevation 325.00. As all stormwater is recharged for the project site and within Post Development Area #3 watershed up to the 100-year storm event. Infiltration was utilized for this practice in the hydraulic model based upon existing test pits/infiltration test results. This area was determined to have a percolation rate greater than 2,000 inches/per hour at elevation 319.0. The model uses a percolation rate of 200 inches/per hour or a safety factor over 12 was used in the calculations. Stormwater Practice Test Pit # Ground Elevation Depth to Ground Water Ground Water Elevation Seasonal High Ground Water Elevation (SHGW) Bottom Elevation of Stormwater Practice Difference between SHGW and bottom of Practice (feet) Field Infiltration Rate (in/hr) Design Infiltration Rate (in/hr) Infiltration Basin #1 TP# 10 323.1 9 314.1 314.1 319.0 4.9 2,466 200 Infiltration Basin #1 TP# 10A 323.1 9 314.1 314.1 319.0 4.9 2,544 200 5.8 Combined Flows to Discharge Point #1, #2 and #3 As stormwater runoff from the site will discharge to various locations, Post Development Area #1, #1A, #2 #3 and #3a must be compared to Pre-Development #1, #2 and #3 at discharge points. Hydraflow Hydrographs software hydraulic model calculations the expect combined Post Development peak discharge rate to various discharge points based upon routing of stormwater practices, what the discharge rates/flows from the stormwater management areas, time and overflow (define as watersheds not going to a stormwater management facility). As the hydraulic modeling simulated for the 1, 2, 10, 25, 50 and 100-year storm events, the post development combined peak flow rate to Discharge Point #1 #2 and #3 can be determined and are listed below. Table-7 Peak Flow to Discharge Point #1 1-Year Flow (cfs) 2-Year Flow (cfs) 10-Year Flow (cfs) 25-Year Flow (cfs) 50-Year Flow (cfs) 100-Year Flow (cfs) Pre Development (Area #1) 0.000 0.000 0.000 0.000 0.007 0.023 Post Combined Peak Flow (Post 1+ Outflow from Wet Swale-Post Area #1A 0.000 0.000 0.000 0.000 0.006 0.018 Net Change in Flow -0.0 -0.0 -0.0 -0.0 -0.001 -0.005 Table-8 Peak Flow to Discharge Point #2 1-Year Flow (cfs) 2-Year Flow (cfs) 10-Year Flow (cfs) 25-Year Flow (cfs) 50-Year Flow (cfs) 100-Year Flow (cfs) Pre Development (Area #2) 0.000 0.000 0.000 0.003 0.044 0.139 Post Combined Peak Flow (Outflow from Array #1-Post Area #2) 0.000 0.000 0.000 0.000 0.000 0.000 Net Change in Flow -0.000 -0.000 -0.000 -0.003 -0.044 -0.139 Stormwater Management Report July 2024 Page 14 Table-9 Peak Flow to Discharge Point #3 1-Year Flow (cfs) 2-Year Flow (cfs) 10-Year Flow (cfs) 25-Year Flow (cfs) 50-Year Flow (cfs) 100-Year Flow (cfs) Pre Development (Area #3) 0.000 0.000 0.000 0.036 0.115 0.485 Post Combined Peak Flow (Post 3+ Outflow from Basin #1-Post Area #3A) 0.000 0.000 0.000 0.029 0.120 0.421 Net Change in Flow -0.000 -0.000 -0.000 -0.007 +0.005 -0.064 5.9 Water Quality Treatment Diversion (STMH#7) Hydraflow Hydrographs software was used to develop a hydraulic model of the flow diversion, STMH #7. STMH #7 will send stormwater runoff to a hydrodynamic unit (WQv#2) or direct stormwater flow to STMH #6 that is connected to the Underground Infiltration Array. The model show as flow rates from Post Development Area #2 water will first go through an 18” pipe at elevation 319.50 to WQv #2 and when the high flow by-pass pipe (invert 321.25 24”x38” arch pipe) will activate and send storm directly to Underground Infiltration Array. Within the model it demonstrates the flow rates going through these two pipes during different storm events, and the net flow (added back together) at the underground array. This is demonstrated by Hydrographs #10, #11 and #12 labeled Flow to WQv #2, High Flow to Array and Flow to Array #1. By including STMH#7 in the model, it demonstrates the piping size and elevations are appropriately designed to convey the 100-year storm event to array and limiting the flow to the hydrodynamic unit as required. Stormwater Management Report July 2024 Page 15 6.0 PROPOSED CONVEYANCE SYSTEM AND DISCHARGE POINT The proposed closed drainage system was designed and verified to pass the 10-year storm event. Calculations for anticipated flow through each pipe run can be found in Exhibit D.1. The anticipated flows through each proposed pipe run were based upon the percentage of watershed flowing to each proposed catch basin. The model of stormwater systems takes into account hydraulic conditions and the model demonstrates that the HGL is within the pipe for the 10-year storm event. Stormwater Management Report July 2024 Page 16 7.0 EXHIBITS Stormwater Management Report July 2024 Page 17 Exhibit A – Soils, Rainfall and CN Calculations .1 24-Hour Rainfall Intensity Table .2 Pre-Development CN .3 Post Development CN .4 NRCS Soil Information and Gifford Engineering Results 12/4/23, 1:16 PM Extreme Precipitation https://precip.eas.cornell.edu/#/product/xprecip_results 1/1 ocat o New o , U ted States Latitude 43.081 degrees North Longitude 73.809 degrees West Elevation 90 feet Date/Time Mon Dec 04 2023 13:16:03 GMT-0500 (Eastern Standard Time) Extreme Precipitation Estimates 5min 10min 15min 30min 60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 1day 2day 1yr 0.27 0.41 0.51 0.67 0.84 1.04 1yr 0.72 0.97 1.20 1.48 1.82 2.23 2.53 1yr 1.98 2.44 2yr 0.33 0.50 0.63 0.83 1.04 1.29 2yr 0.90 1.15 1.47 1.79 2.17 2.61 2.93 2yr 2.31 2.82 5yr 0.39 0.60 0.76 1.01 1.30 1.62 5yr 1.12 1.43 1.85 2.24 2.69 3.19 3.59 5yr 2.82 3.46 10yr 0.44 0.69 0.87 1.18 1.53 1.93 10yr 1.32 1.68 2.20 2.66 3.16 3.71 4.20 10yr 3.29 4.03 25yr 0.52 0.82 1.05 1.44 1.92 2.42 25yr 1.65 2.08 2.76 3.32 3.91 4.54 5.15 25yr 4.02 4.95 50yr 0.58 0.94 1.20 1.68 2.28 2.89 50yr 1.96 2.45 3.30 3.95 4.61 5.30 6.02 50yr 4.69 5.79 100yr 0.67 1.08 1.40 1.98 2.70 3.43 100yr 2.33 2.89 3.92 4.66 5.42 6.19 7.04 100yr 5.47 6.77 200yr 0.76 1.24 1.61 2.31 3.20 4.08 200yr 2.76 3.40 4.66 5.52 6.37 7.22 8.23 200yr 6.39 7.91 500yr 0.92 1.51 1.97 2.86 4.01 5.13 500yr 3.46 4.23 5.85 6.90 7.90 8.87 10.13 500yr 7.85 9.74 Lower Confidence Limits 5min 10min 15min 30min 60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 1day 2day 1yr 0.22 0.34 0.41 0.56 0.68 0.82 1yr 0.59 0.80 0.93 1.23 1.59 1.94 2.29 1yr 1.71 2.20 2yr 0.31 0.48 0.59 0.80 0.98 1.14 2yr 0.85 1.12 1.28 1.65 2.05 2.53 2.84 2yr 2.24 2.74 5yr 0.36 0.55 0.69 0.94 1.20 1.34 5yr 1.04 1.31 1.50 1.92 2.45 2.98 3.36 5yr 2.63 3.23 10yr 0.40 0.61 0.76 1.06 1.37 1.52 10yr 1.19 1.48 1.70 2.15 2.73 3.36 3.79 10yr 2.98 3.64 25yr 0.46 0.71 0.88 1.25 1.65 1.78 25yr 1.42 1.74 2.00 2.50 3.19 3.97 4.47 25yr 3.51 4.29 50yr 0.52 0.79 0.98 1.41 1.90 2.01 50yr 1.64 1.97 2.24 2.79 3.58 4.49 5.06 50yr 3.97 4.86 100yr 0.58 0.88 1.10 1.59 2.18 2.28 100yr 1.88 2.23 2.54 3.12 4.03 5.08 5.74 100yr 4.50 5.52 200yr 0.65 0.98 1.24 1.80 2.51 2.57 200yr 2.17 2.52 2.87 3.49 4.52 5.76 6.51 200yr 5.10 6.26 PROJECT #2022-02 SHEET #1 OF:2 PAGE #OF: MADE BY: DATE: PROJECT:Staton Park CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: 1 Applicable Standards: 2 Urban Hydrology for Small Watersheds, Technical Release 55. USDA, June 1986. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Comments: 37 100% 1 Source: TR-55, Tables 2-2a,b,c. 0.0 0 sq. mi 0% 0.0 0 0.016 0% 0.0 0 0% 0.0 0 =0% 0% 0.0 0.0 310acres0% 0.0 0 10.554 0% 0% 0.0 2% 0.7 0 =0% 0.0 1% 1.0 446,993 Woods (Good)A 30 sq. feet 97% 29.2 #2 4,750 Paved parking lots,roofs etc.A 98 459,743 8,000 Urban Open Space, Good (> 75% grass)A 39 0 0 459,743 105,201 100% AREA Land Use Land Use / Cover Description1 Hydrologic Actual AREA #1 Factored CN Weighted Area (feet2)Soil Group1 CN1 Area (feet2) % CN CN 0.0 0 sq. mi 0% 0.0 0 0.004 0% 0.0 0 0% 0.0 0 =0% 0 0% 0.0 0.0 300acres0% 0.0 0 2.415 0% 0 0% 0.0 0% 0.0 0 =0% 0.0 0 100% 30.0 0 sq. feet 0% 0.0 105,201 Woods (Good)A 30 105,201 PRE-DEVELOPMENT AREA Land Use Land Use / Cover Description1 Hydrologic Actual AREA Factored CN Weighted Area (feet2)Soil Group1 CN1 Area (feet2) % CN CN JWE 5/14/2024 Pre-Development Condition AREA #1 & #2 EP Land Services LLC 7/12/2024 CN.xlsx.xls PRE PROJECT #2022-02 SHEET #2 OF:2 PAGE #OF: MADE BY: DATE: PROJECT:Staton Park CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: 1 Applicable Standards: 2 Urban Hydrology for Small Watersheds, Technical Release 55. USDA, June 1986. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Comments: 37 0% 1 Source: TR-55, Tables 2-2a,b,c. 0.0 0 sq. mi 0% 0.0 0 0.000 0% 0.0 0 0% 0.0 0 =0% 0% 0.0 0.0 00acres0% 0.0 0 0.000 0% 0% 0.0 0% 0.0 0 =0% 0.0 0% 0.0 0 sq. feet 0% 0.0 0 0 0 0 0 - 369,350 100% AREA Land Use Land Use / Cover Description1 Hydrologic Actual AREA #3 Factored CN Weighted Area (feet2)Soil Group1 CN1 Area (feet2) % CN CN 0.0 0 sq. mi 0% 0.0 0 0.013 0% 0.0 0 0% 0.0 0 =0% 0 0% 0.0 0.0 350acres0% 0.0 0 8.479 0% 0 0% 0.0 1% 1.0 333,350 Woods (Good)A 30 =90% 27.1 5,000 Streets, Gravel A 76 6% 5.6 10,000 Urban Open Space, Good (> 75% grass)A 39 sq. feet 3% 1.1 21,000 Paved parking lots,roofs etc.A 98 369,350 PRE-DEVELOPMENT AREA Land Use Land Use / Cover Description1 Hydrologic Actual AREA Factored CN Weighted Area (feet2)Soil Group1 CN1 Area (feet2) % CN CN JWE 5/14/2024 Pre-Development Condition AREA #3 EP Land Services LLC 7/12/2024 CN.xlsx.xls PRE (2) PROJECT #2022-02 SHEET #1 OF:3 PAGE #OF: MADE BY: DATE: PROJECT:Station Park CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: 1 Applicable Standards: 2 Urban Hydrology for Small Watersheds, Technical Release 55. USDA, June 1986. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Comments: 37 JWE 5/14/2024 Post-Development Condition AREA #1 and #1A POST-DEVELOPMENT AREA Land Use Land Use / Cover Description1 Hydrologic Actual AREA Factored CN Weighted Area (feet2)Soil Group1 CN1 Area (feet2) % CN CN 88% 26.4 6,927 Urban Open Space, Good (> 75% grass)A 39 sq. feet 12% 4.6 51,321 Woods (Good)A 30 58,248 0 0% 0.0 0% 0.0 0 =0% 0.0 0 0 0% 0.0 0.0 310acres0% 0.0 0 1.337 0% 0.0 0 0% 0.0 0 =0% 0 sq. mi 0% 0.0 0 0.002 0% 58,248 100% AREA Land Use Land Use / Cover Description1 Hydrologic Actual AREA #1 Factored CN Weighted Area (feet2)Soil Group1 CN1 Area (feet2) % CN CN 0.0 #1A 18,869 Paved parking lots,roofs etc.A 98 30,725 0 0 0 30,725 61% 60.2 11,856 Urban Open Space, Good (> 75% grass)A 39 sq. feet 39% 15.0 0% 0.0 0% 0.0 0 =0% 0.0 0% 0.0 0.0 750acres0% 0.0 0 0.705 0% 0.0 0 0% 0.0 0 =0% 100% 1 Source: TR-55, Tables 2-2a,b,c. 0.0 0 sq. mi 0% 0.0 0 0.001 0% EP Land Service LLC 7/12/2024 CN.xlsx.xls POST PROJECT #2022-02 SHEET #2 OF:3 PAGE #OF: MADE BY: DATE: PROJECT:Station Park CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: 1 Applicable Standards: 2 Urban Hydrology for Small Watersheds, Technical Release 55. USDA, June 1986. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Comments: 37 100% 1 Source: TR-55, Tables 2-2a,b,c. 0.0 0 sq. mi 0% 0.0 0 0.005 0% 0.0 0 0% 0.0 0 =0% 0% 0.0 0.0 380acres0% 0.0 0 3.008 0% 0% 0.0 65% 19.6 0 =0% 0.0 8% 7.9 34,760 Urban Open Space, Good (> 75% grass)A 39 sq. feet 27% 10.3 #3 10,600 Paved parking lots,roofs etc.A 98 131,036 85,676 Woods (Good)A 30 0 0 131,036 561,846 100% AREA Land Use Land Use / Cover Description1 Hydrologic Actual AREA #2 Factored CN Weighted Area (feet2)Soil Group1 CN1 Area (feet2) % CN CN 0.0 0 sq. mi 0% 0.0 0 0.020 0% 0.0 0 0% 0.0 0 =0% 0 0% 0.0 0.0 800acres0% 0.0 0 12.898 0% 0 0% 0.0 2% 0.6 0 =0% 0.0 11,795 Woods (Good)A 30 69% 68.0 159,996 Urban Open Space, Good (> 75% grass)A 39 sq. feet 28% 11.1 390,055 Paved parking lots,roofs etc.A 98 561,846 POST-DEVELOPMENT AREA Land Use Land Use / Cover Description1 Hydrologic Actual AREA Factored CN Weighted Area (feet2)Soil Group1 CN1 Area (feet2) % CN CN JWE 5/14/2024 Post-Development Condition AREA #2 and #3 EP Land Service LLC 7/12/2024 CN.xlsx.xls POST (2) PROJECT #2022-02 SHEET #3 OF:3 PAGE #OF: MADE BY: DATE: PROJECT:Station Park CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: 1 Applicable Standards: 2 Urban Hydrology for Small Watersheds, Technical Release 55. USDA, June 1986. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Comments: 37 0% 1 Source: TR-55, Tables 2-2a,b,c. 0.0 0 sq. mi 0% 0.0 0 0.000 0% 0.0 0 0% 0.0 0 =0% 0% 0.0 0.0 00acres0% 0.0 0 0.000 0% 0% 0.0 0% 0.0 0 =0% 0.0 0% 0.0 0 sq. feet 0% 0.0 0 0 0 0 0 - 154,702 100% AREA Land Use Land Use / Cover Description1 Hydrologic Actual AREA #3A Factored CN Weighted Area (feet2)Soil Group1 CN1 Area (feet2) % CN CN 0.0 0 sq. mi 0% 0.0 0 0.006 0% 0.0 0 0% 0.0 0 =0% 0 0% 0.0 0.0 760acres0% 0.0 0 3.551 0% 0 0% 0.0 0% 0.0 0 =0% 0.0 0 63% 62.2 56,548 Urban Open Space, Good (> 75% grass)A 39 sq. feet 37% 14.3 98,154 Paved parking lots,roofs etc.A 98 154,702 POST-DEVELOPMENT AREA Land Use Land Use / Cover Description1 Hydrologic Actual AREA Factored CN Weighted Area (feet2)Soil Group1 CN1 Area (feet2) % CN CN JWE 5/14/2024 Post-Development Condition AREA #3A EP Land Service LLC 7/12/2024 CN.xlsx.xls POST (3) Soil Map—Saratoga County, New York Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/4/2023 Page 1 of 34770270477033047703904770450477051047705704770630477069047702704770330477039047704504770510477057047706304770690596800596860596920596980597040597100 596800 596860 596920 596980 597040 597100 43° 4' 58'' N 73° 48' 40'' W43° 4' 58'' N73° 48' 24'' W43° 4' 43'' N 73° 48' 40'' W43° 4' 43'' N 73° 48' 24'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 100 200 400 600 Feet 0 30 60 120 180 Meters Map Scale: 1:2,350 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Saratoga County, New York Survey Area Data: Version 23, Sep 6, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Sep 9, 2022—Oct 22, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Soil Map—Saratoga County, New York Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/4/2023 Page 2 of 3 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI DeA Deerfield loamy fine sand, 0 to 3 percent slopes 8.1 43.6% Sa Scarboro mucky fine sandy loam, 0 to 3 percent slopes 3.0 16.3% Wa Wareham loamy sand 0.1 0.7% WnB Windsor loamy sand, 3 to 8 percent slopes 0.8 4.5% WnC Windsor loamy sand, 8 to 15 percent slopes 6.4 34.9% Totals for Area of Interest 18.5 100.0% Soil Map—Saratoga County, New York Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/4/2023 Page 3 of 3 Water Features This table gives estimates of various soil water features. The estimates are used in land use planning that involves engineering considerations. Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The four hydrologic soil groups are: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Surface runoff refers to the loss of water from an area by flow over the land surface. Surface runoff classes are based on slope, climate, and vegetative cover. The concept indicates relative runoff for very specific conditions. It is assumed that the surface of the soil is bare and that the retention of surface water resulting from irregularities in the ground surface is minimal. The classes are negligible, very low, low, medium, high, and very high. The months in the table indicate the portion of the year in which a water table, ponding, and/or flooding is most likely to be a concern. Water Features---Saratoga County, New York Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/4/2023 Page 1 of 5 Water table refers to a saturated zone in the soil. The water features table indicates, by month, depth to the top ( upper limit ) and base ( lower limit ) of the saturated zone in most years. Estimates of the upper and lower limits are based mainly on observations of the water table at selected sites and on evidence of a saturated zone, namely grayish colors or mottles (redoximorphic features) in the soil. A saturated zone that lasts for less than a month is not considered a water table. The kind of water table, apparent or perched, is given if a seasonal high water table exists in the soil. A water table is perched if free water is restricted from moving downward in the soil by a restrictive feature, in most cases a hardpan; there is a dry layer of soil underneath a wet layer. A water table is apparent if free water is present in all horizons from its upper boundary to below 2 meters or to the depth of observation. The water table kind listed is for the first major component in the map unit. Ponding is standing water in a closed depression. Unless a drainage system is installed, the water is removed only by percolation, transpiration, or evaporation. The table indicates surface water depth and the duration and frequency of ponding. Duration is expressed as very brief if less than 2 days, brief if 2 to 7 days, long if 7 to 30 days, and very long if more than 30 days. Frequency is expressed as none, rare, occasional, and frequent. None means that ponding is not probable; rare that it is unlikely but possible under unusual weather conditions (the chance of ponding is nearly 0 percent to 5 percent in any year); occasional that it occurs, on the average, once or less in 2 years (the chance of ponding is 5 to 50 percent in any year); and frequent that it occurs, on the average, more than once in 2 years (the chance of ponding is more than 50 percent in any year). Flooding is the temporary inundation of an area caused by overflowing streams, by runoff from adjacent slopes, or by tides. Water standing for short periods after rainfall or snowmelt is not considered flooding, and water standing in swamps and marshes is considered ponding rather than flooding. Duration and frequency are estimated. Duration is expressed as extremely brief if 0.1 hour to 4 hours, very brief if 4 hours to 2 days, brief if 2 to 7 days, long if 7 to 30 days, and very long if more than 30 days. Frequency is expressed as none, very rare, rare, occasional, frequent, and very frequent. None means that flooding is not probable; very rare that it is very unlikely but possible under extremely unusual weather conditions (the chance of flooding is less than 1 percent in any year); rare that it is unlikely but possible under unusual weather conditions (the chance of flooding is 1 to 5 percent in any year); occasional that it occurs infrequently under normal weather conditions (the chance of flooding is 5 to 50 percent in any year); frequent that it is likely to occur often under normal weather conditions (the chance of flooding is more than 50 percent in any year but is less than 50 percent in all months in any year); and very frequent that it is likely to occur very often under normal weather conditions (the chance of flooding is more than 50 percent in all months of any year). The information is based on evidence in the soil profile, namely thin strata of gravel, sand, silt, or clay deposited by floodwater; irregular decrease in organic matter content with increasing depth; and little or no horizon development. Water Features---Saratoga County, New York Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/4/2023 Page 2 of 5 Also considered are local information about the extent and levels of flooding and the relation of each soil on the landscape to historic floods. Information on the extent of flooding based on soil data is less specific than that provided by detailed engineering surveys that delineate flood-prone areas at specific flood frequency levels. Water Features---Saratoga County, New York Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/4/2023 Page 3 of 5 Report—Water Features Map unit symbol and soil name Hydrologic group Surface runoff Most likely months Water table Ponding Flooding Upper limit Lower limit Kind Surface depth Duration Frequency Duration Frequency Ft Ft Ft DeA—Deerfield loamy fine sand, 0 to 3 percent slopes Deerfield A Negligible Jan-Jun 1.2-3.1 4.9-6.0 Apparent ——None —None Jul-Oct —————None —None Nov-Dec 1.2-3.1 4.9-6.0 Apparent ——None —None Sa—Scarboro mucky fine sandy loam, 0 to 3 percent slopes Scarboro A/D Negligible Jan-Jun 0.0-0.2 5.4 Apparent 0.0-1.0 Long (7 to 30 days) Frequent —None Jul-Oct 0.0-1.6 5.4 Apparent 0.0-1.0 Long (7 to 30 days) Frequent —None Nov-Dec 0.0-0.2 5.4 Apparent 0.0-1.0 Long (7 to 30 days) Frequent —None Wa—Wareham loamy sand Wareham, poorly drained A/D Jan-Jun 0.0-1.5 6.0 Apparent ——None —None Jul-Aug —————None —None Sep-Dec 0.0-1.5 6.0 Apparent ——None —None WnB—Windsor loamy sand, 3 to 8 percent slopes Windsor A Negligible Jan-Dec —————None —None WnC—Windsor loamy sand, 8 to 15 percent slopes Windsor A Low Jan-Dec —————None —None Water Features---Saratoga County, New York Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/4/2023 Page 4 of 5 GIFFORD ENGINEERING Geotechnical & Geoenvironmental Services 865 Pearse Road Niskayuna, NY 12309 Tel (518) 382-2545 giffeng@nycap.rr.com INFILTRATION TEST RESULTS Station Park NYS Route 29 (Washington St) Saratoga Springs, NY 12866 File No. 2403 Slug permeability testing was performed in infiltration wells in accordance with ASTM D 4044. Locations and depths of tests were assigned by Mr. James Easton, PE, of EP Land Services. Test pits were excavated to two feet above the assigned depth. From the bottom of the test pits, the borehole was manually advanced with a post hole digger. HDPE pipes, 4-inches in diameter, were placed at varying depths, as directed by Mr. Easton. The annular space between the HDPE wells and borehole sidewalls were sealed off near the bottom with bentonite chips and backfilled with spoils. The test procedure involves saturating the soils beneath the wells then adding water to the wells and recording time as the water level drops. A 5-gallon bucket was emptied into the pipes, filling them to the top of pipe, and the timer started. The time required for the water to drain two feet below the top of the pipe was recorded. At P-1, the infiltration well was only 1 foot deep so the procedure was adjusted. A minimum of four tests were performed in each well until the time readings stabilized. The infiltration rates (inches per minute) reported below are for the last test at each location. The test allows for calculation of coefficient of permeability or hydraulic conductivity (cm per sec), the results are given below. Permeability calculations are from equations in Table 2.6 in “Seepage, Drainage and Flow Nets” by Harry R. Cedergren, (1967), John Wiley & Sons. 2 11,RFrShapeFacto= )ln( )(11 2)ln(, 2 1 122 1 2 h h tt R h h Ft RktyPermeabili - P=P= Slug Permeability Tests were performed on June 20, 2024. Well No. Depth to Bottom of Well* Depth to Ground Water** Coeff. of Permeability (cm/sec) Infiltration Rate (in/min) P-1 1.0’ +/- 5.5’ +/- 4.48 x 10-5 0.5 P-5 4.0’ +/- 4.0’ +/- 8.30 x 10-4 5.1 P-6 4.0’ +/- 4.0’ +/- 8.16 x 10-4 5.0 P-8 5.0’ +/- 7.5’ +/- 6.27 x 10-2 720*** P-8A 5.0’ +/- 7.5’ +/- 6.27 x 10-2 720*** P-10 3.0’ +/- >9.0’ 2.18 x 10-3 41.1 P-10A 3.0’ +/- >9.0’ 2.24 x 10-3 42.4 * Measured depth of well from ground surface. ** Ground water measured in separate test pit next to test boring. *** Unable to fill pipe with 5-gallon bucket, water drained 24-inches in about 2 seconds. Stormwater Management Report July 2024 Page 18 Exhibit B – WQv and Pretreatment .1 WQv calculations .2 Hydrodynamic Unit information .3 WQv Peak flows Version 1.8 Last Updated: 11/09/2015 Total Water Quality Volume Calculation WQv(acre-feet) = [(P)(Rv)(A)] /12 No Design Point:1 P= 1.15 inch Catchment Number Total Area (Acres) Impervious Area (Acres) Percent Impervious % Rv WQv (ft 3 ) Description 1 0.71 0.46 65% 0.63 1,860 Post Area #1A 2 12.90 9.95 77% 0.74 40,075 Post Area #2 3 3.55 2.25 63% 0.62 9,194 Post Area #3 4 5 6 7 8 9 10 Subtotal (1-30)17.16 12.66 74% 0.71 51,130 Subtotal 1 Total 17.16 12.66 74% 0.71 51,130 Initial WQv Total Contributing Area Contributing Impervious Area (Acre) (Acre) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Total Area (Acres) Impervious Area (Acres) Percent Impervious % Runoff Coefficient Rv WQv (ft 3 ) 17.16 12.66 74% 0.71 51,130 0.00 0.00 17.16 12.66 74% 0.71 51,130 0.00 17.16 12.66 74% 0.71 51,130 0 Identify Runoff Reduction Techniques By Area Breakdown of Subcatchments Is this project subject to Chapter 10 of the NYS Design Manual (i.e. WQv is equal to post- development 1 year runoff volume)?...................................................................................... "<<Initial WQv" Recalculate WQv after application of Area Reduction Techniques Riparian Buffers maximum contributing length 75 feet to 150 feet Up to 100 sf directly connected impervious area may be subtracted per treeTree Planting Filter Strips Total Manually enter P, Total Area and Impervious Cover. NotesTechnique minimum 10,000 sfConservation of Natural Areas WQv reduced by Area Reduction techniques Adjusted WQv after Area Reduction and Rooftop Disconnect Subtract Area Disconnection of Rooftops WQv adjusted after Area Reductions Runoff Reduction Techiques/Standard SMPs Total Contributing Area Total Contributing Impervious Area WQv Reduced (RRv) WQv Treated (acres) (acres) cf cf Conservation of Natural Areas RR-1 0.00 0.00 Sheetflow to Riparian Buffers/Filter Strips RR-2 0.00 0.00 Tree Planting/Tree Pit RR-3 0.00 0.00 Disconnection of Rooftop Runoff RR-4 0.00 Vegetated Swale RR-5 0.00 0.00 0 Rain Garden RR-6 0.00 0.00 0 Stormwater Planter RR-7 0.00 0.00 0 Rain Barrel/Cistern RR-8 0.00 0.00 0 Porous Pavement RR-9 0.00 0.00 0 Green Roof (Intensive & Extensive) RR-10 0.00 0.00 0 Infiltration Trench I-1 0.00 0.00 0 0 Infiltration Basin I-2 3.55 2.25 9194 0 Dry Well I-3 0.00 0.00 0 0 Underground Infiltration System I-4 12.90 9.95 40075 Bioretention & Infiltration Bioretention F-5 0.00 0.00 0 0 Dry swale O-1 0.00 0.00 0 0 Micropool Extended Detention (P-1) P-1 Wet Pond (P-2) P-2 Wet Extended Detention (P-3) P-3 Multiple Pond system (P-4) P-4 Pocket Pond (p-5) P-5 Surface Sand filter (F-1) F-1 Underground Sand filter (F-2) F-2 Perimeter Sand Filter (F-3) F-3 Organic Filter (F-4 F-4 Shallow Wetland (W-1) W-1 Extended Detention Wetland (W-2 W-2 Pond/Wetland System (W-3) W-3 Pocket Wetland (W-4) W-4 Wet Swale (O-2) O-2 0.71 0.46 1860 →0.00 0.00 0 →0.00 0.00 0 →16.45 12.20 49270 0 →0.71 0.46 1860 → 17.16 12.66 49,270 1,860 Impervious Cover √ okay Totals by Volume Reduction Totals by Standard SMP w/RRV Totals by Standard SMP Totals ( Area + Volume + all SMPs) Runoff Reduction Volume and Treated volumes Standard SMPs w/RRv CapacityStandard SMPs Area/Volume ReductionTotals by Area Reduction Minimum RRv Soil Group Acres S A 17.15 55% B 40% C 30% D 20% Total Area 17.15 S =0.55 Impervious = 12.66 acre Precipitation 1.15 in Rv 0.95 Minimum RRv 27,605 ft3 0.63 af Enter the Soils Data for the site Calculate the Minimum RRv NOI QUESTIONS # cf af 28 51130 1.174 30 49270 1.131 31 32 27605 0.634 32a 33a 1860 0.043 34 51130 1.174 34 51130 1.174 35 36 Cpv 37 Qp 37 Qf Reported Value Yes No Yes Minimum RRv NOI Question Sum of Volume Reduced & Treated Total WQv Treated Total RRV Provided Total Water Quality Volume (WQv) Required Is Sum RRv Provided and WQv Provided ≥WQv Required? Sum of Volume Reduced and Treated Is RRv Provided ≥ Minimum RRv Required? Is RRv Provided ≥WQv Required? Are Quantity Control requirements met? Channel Protection Apply Peak Flow Attenuation Overbank Extreme Flood Control Infiltration Basin Worksheet Design Point:1 Catchment Number Total Area (Acres) Impervious Area (Acres) Percent Impervious % Rv WQv (ft 3 ) Precipitation (in)Description 3 3.55 2.25 0.63 0.62 9194.34 1.15 Post Area #3 0.00 63% 0.62 9,194 0 ft 3 200.00 in/hour 100 % WQv 9,194 ft 3 10,000 ft 3 Design Volume 9,194 ft 3 Basal Area Required 1,532 ft 2 Basal Area Provided 2,000 ft 2 Design Depth 6.00 ft Volume Provided 12,000 ft 3 RRv 9,194 ft 3 Volume Treated 0 ft 3 Sizing √ OK Size An Infiltration Basin Storage Volume provided in infiltration basin area (not including pretreatment. Determine Runoff Reduction Enter Site Data For Drainage Area to be Treated by Practice Enter Impervious Area Reduced by Disconnection of Rooftops <<WQv after adjusting for Disconnected Rooftops Enter the portion of the WQv that is not reduced for all practices routed to this practice. Pretreatment Techniques to Prevent Clogging Pretreatment Provided Infiltration Rate Okay Pretreatment Sizing 25% minimum; 50% if >2 in/hr 100% if >5in/hour Pretreatment Required Volume Pretreatment Techniques utilized Other WQv 90% of the storage provided in the basin or WQv whichever is smaller This is the portion of the WQv that is not reduced/infiltrated Infiltration practices shall be designed to exfiltrate the entire WQv through the floor of each practice. The infiltration basin must provide storage equal to or greater than the WQv of the contributing area. VortSentry®VortSentry® HS Hydrodynamic Separation Products Overview page 2 page 3 High performance hydrodynamic separation The Vortechs system is a high-performance hydrodynamic separator that effectively removes finer sediment, oil and grease, and floating and sinking debris. Its swirl concentrator and flow controls work together to minimize turbulence and provide stable storage of captured pollutants. The design also allows for easy inspection and unobstructed maintenance access. With comprehensive lab and field testing, the system delivers proven results and site-specific solutions. Precast models can treat peak design flows up to 25 cfs; cast-in-place models handle even greater flows. A typical system is sized to provide an 80% load reduction based on laboratory-verified removal efficiencies for varying particle size distributions such as 50-micron sediment particles. How does it work? Water enters the swirl chamber at a tangent, inducing a gentle swirling flow pattern and enhancing gravitational separation. Sinking pollutants stay in the swirl chamber while floating pollutants are stopped at the baffle wall. Typically Vortechs systems are sized such that 80% or more of runoff through the system will be controlled exclusively by the low flow control. This orifice effectively reduces inflow velocity and turbulence by inducing a slight backwater appropriate to the site. During larger storms, the water level rises above the low flow control and begins to flow through the high flow control. The layer of floating pollutants is elevated above the influent pipe, preventing re-entrainment. Swirling action increases in relation to the storm intensity, which helps prevent re-suspension. When the storm drain is flowing at peak capacity, the water surface in the system approaches the top of the high flow control. The Vortechs system will be sized large enough so that previously captured pollutants are retained in the system even during these infrequent events. As a storm subsides, treated runoff decants out of the Vortechs system at a controlled rate, restoring the water level to a dry-weather level equal to the invert of the inlet and outlet pipes. The low water level facilitates easier inspection and cleaning, and significantly reduces maintenance costs by reducing pump-out volume. Vortechs Proven performance speeds approval process Treats peak flows without bypassing Flow controls reduce inflow velocity and increase residence time Unobstructed access simplifies maintenance Shallow system profile makes installation easier and less expensive Very low headloss Flexible design fits multiple site constraints • • • • • • • Vortechs ® page 2 page 3 Patented continuous deflection separation (CDS) technology Using patented continuous deflective separation technology, the CDS system screens, separates and traps sediment, debris, and oil and grease from stormwater runoff. The indirect screening capability of the system allows for 100% removal of floatables and neutrally buoyant material without blinding. Flow and screening controls physically separate captured solids, and minimize the re-suspension and release of previously trapped pollutants. Available in precast or cast-in-place. Offline units can treat flows from 30 to 8500 L/s (1 to 300 cfs). Inline units can treat up to 170 L/s (7.5 cfs), and internally bypass larger flows in excess of 1420 L/s (50 cfs). The pollutant removal capability of the CDS system has been proven in the lab and field. How does it work? Stormwater enters the CDS unit’s diversion chamber where the diversion weir guides the flow into the unit’s separation chamber and pollutants are removed. All flows up to the system’s treatment design capacity enter the separation chamber. Swirl concentration and screen deflection forces floatables and solids to the center of the separation chamber where 100% of floatables and neutrally buoyant debris larger than the screen apertures are trapped. Stormwater then moves through the separation screen, under the oil baffle and exits the system. The separation screen remains clog free due to continuous deflection. During flow events exceeding the design capacity, the diversion weir bypasses excessive flows around the separation chamber, so captured pollutants will not wash out. CDS Removes sediment, trash, and free oil and grease Patented screening technology captures and retains 100% of floatables, including neutrally buoyant and all other material larger than the screen aperture Operation independent of flow Performance verified through lab and field testing Unobstructed maintenance access Customizable/flexible design and multiple configurations available Separates and confines pollutants from outlet flow Inline, offline, grate inlet and drop inlet configurations available Multiple screen aperture sizes available • • • • • • • • • CDS ® page 4 page 5 Hydrodynamic separation with internal bypass The VortSentry is a hydrodynamic separator with a small footprint that makes it an effective treatment option for projects where space is at a premium and effective removal of floating and sinking pollutants is critical. The internal bypass ensures treatment chamber velocities remain low, which improves performance and eliminates the risk of resuspension. In addition to standalone applications, the VortSentry is an ideal pretreatment device. The system is housed inside a concrete manhole structure for easy installation (often without the use of a crane) and unobstructed maintenance access. How does it work? Stormwater runoff enters the unit tangentially to promote a gentle swirling motion in the treatment chamber. As stormwater circles within the chamber, settleable solids fall into the sump and are retained. Buoyant debris and oil and grease rise to the surface and are separated from the water as it flows under the baffle wall. Treated water exits the treatment chamber through a flow control orifice located behind the baffle wall. During low-flow conditions all runoff is diverted into the treatment chamber by the flow partition. At higher flow rates, a portion of the runoff spills over the flow partition and is diverted around the treatment chamber, filling the head equalization chamber. This collapses the head differential between the treatment chamber and the outlet, resulting in a relatively constant flow rate in the treatment chamber even with a substantial increase in total flow through the system. This further reduces the potential for resuspension or washout of captured pollutants. VortSentry ® VortSentry Treatment and internal bypass in one structure Compact design ideal for congested sites Unobstructed maintenance access Round, lightweight construction for easy installation • • • • page 4 page 5 VortSentry ® HS VortSentry HS Helical flow pattern enhances trapping and containment of pollutants High treatment and bypass capacities Compact footprint ideal for congested sites Lightweight design easy to install Available in both inline and grate inlet configurations Quick manufacturing turnaround time • • • • • • Engineered performance and installation simplicity The VortSentry HS system employs a helical flow pattern that enhances trapping and containment of pollutants and provides effective removal of settleable solids and floating contaminants from urban runoff. With the ability to accept a wide range of pipe sizes, the VortSentry HS can treat and convey flows from small to large sites. A unique internal bypass design means higher flows can be diverted without the use of external bypass structures. The design of the VortSentry HS minimizes adverse velocities or turbulence in the treatment chamber. This helps to prevent the washout of previously captured pollutants even during peak conditions. The VortSentry HS is also available in a grate inlet configuration, which is ideal for retrofits. How does it work? Flows from low intensity storms, which are most frequent, are directed into the treatment chamber through the primary inlet. The tangentially oriented downward pipe induces a swirling motion in the treatment chamber that increases capture and containment abilities. Moderate storm flows are directed into the treatment chamber through the secondary inlet, which allows for capture of floating trash and debris. The secondary inlet also provides for treatment of higher flows without significantly increasing the velocity or turbulence in the treatment chamber. This allows for a more quiescent separation environment. Settleable solids and floating pollutants are captured and contained in the treatment chamber. Flow exits the treatment chamber through the outlet flow control, which manages the amount of flow that is treated and helps maintain the helical flow patterns developed within the treatment chamber. Flows exceeding the system’s rated treatment flow are diverted away from the treatment chamber by the flow partition. Internal diversion of high flows eliminates the need for external bypass structures. During bypass, the head equalizing baffle applies head on the outlet flow control to limit the flow through the treatment chamber. This helps prevent re-suspension of previously captured pollutants. page 6 page 7 Available Models 1. Structure diameter represents the typical inside dimension of the concrete structure. Offline systems will require additional concrete diversion components. 2. Depth Below Pipe and Sump Capacities can vary to accommodate specific site design. 3. Water Quality Flow is based on 80% removal of a Particle Size Distribution (PSD) having a mean particle size: d50=125-µm, which is a typical PSD gradation characterizing particulate matter (TSS/SSC) in urban rainfall runoff. Water Quality Flow, Particle Size & Performance Notes: • 80% removal (Re=80%) performance forecasts of the PSD having a d50=125-µm is derived from controlled tests of a unit equipped with 2400-µm screen. Performance forecasts for specific particle size gradations or d50s=50, 75, 125, 150 & 200-µm are also available. Removal forecasts based on unit evaluations conducted in accordance with the Technology Assessment Protocol - Ecology (TAPE) protocols, Washington Department of Ecology (WASDOE). • Units can be sized to achieve specific Re performance for peak flow rates for specific Water Quality Flows, over the hydrograph of a Water Quality Storm Event or sized to meet a specific removal on an average basis using accepted probabilistic methods. When sizing based on a specific water quality flow rate, the required flow to be treated should be equal to or less than the listed water quality flow for the selected system. Contact our support staff for the most cost effective sizing for your area. Typical Internal MH Diameter or Typical Depth2 Below Water Quality Flow3 Screen Typical Equivalent ID1 Pipe Invert 125 µm Diameter/Height Sump Capacity CDS Model ft m ft m cfs L/s ft m yd3 m3 CDS2015-4 4 1.2 3.5 1.1 0.7 19.8 2.0/1.5 0.6/0.5 0.5 0.4 CDS2015 5 1.5 5.2 1.6 0.7 19.8 2.0/1.5 0.6/0.5 1.3 1.0 CDS2020 5 1.5 5.7 1.7 1.1 31.2 2.0/2.0 0.6/0.6 1.3 1.0 CDS2025 5 1.5 6.0 1.8 1.6 45.3 2.0/2.5 0.6/0.8 1.3 1.0 CDS3020 6 1.8 6.2 1.9 2.0 56.6 3.0/2.0 0.9/0.6 2.1 1.6 CDS3030 6 1.8 7.1 2.2 3.0 85.0 3.0/3.0 0.9/0.9 2.1 1.6 CDS3035 6 1.8 7.6 2.3 3.8 106.2 3.0/3.5 0.9/1.1 2.1 1.6 CDS4030 8 2.4 8.6 2.6 4.5 127.4 4.0/3.0 1.2/0.9 5.6 4.3 CDS4040 8 2.4 9.7 3.0 6.0 169.9 4.0/4.0 1.2/1.2 5.6 4.3 CDS4045 8 2.4 10.3 3.1 7.5 212.4 4.0/4.5 1.2/1.4 5.6 4.3 CDS3020-D 6 1.8 6.2 1.9 2.0 56.6 3.0/2.0 0.9/0.6 2.1 1.6 CDS3030-DV 6 1.8 6.9 2.1 3.0 85.0 3.0/3.0 0.9/0.9 2.1 1.6 CDS3030-D 6 1.8 7.1 2.2 3.0 85.0 3.0/3.0 0.9/0.9 2.1 1.6 CDS3035-D 6 1.8 8.7 2.6 3.8 106.2 3.0/3.5 0.9/1.1 2.1 1.6 CDS4030-D 7 2.1 8.6 2.6 4.5 127.4 4.0/3.0 1.2/0.9 4.3 3.3 CDS4040-D 7 2.1 9.6 2.9 6.0 169.9 4.0/4.0 1.2/1.2 4.3 3.3 CDS4045-D 7 2.1 10.1 3.1 7.5 212.4 4.0/4.5 1.2/1.4 4.3 3.3 CDS5042-DV 9.5 2.9 9.6 2.9 9.0 254.9 5.0/4.2 1.5/1.3 1.9 1.5 CDS5640-D 8 2.4 9.5 2.9 9.0 254.9 5.6/4.0 1.7/1.2 5.6 4.3 CDS5050-DV 9.5 2.9 10.3 3.1 11 311.5 5.0/5.0 1.5/1.5 1.9 1.5 CDS5653-D 8 2.4 10.9 3.3 14 396.5 5.6/5.3 1.7/1.6 5.6 4.3 CDS5668-D 8 2.4 12.4 3.8 19 538.1 5.6/6.8 1.7/2.1 5.6 4.3 CDS5678-D 8 2.4 13.4 4.1 25 708.0 5.6/7.8 1.7/2.4 5.6 4.3 CDS7070-DV 12 3.7 14 4.3 26 736.3 7.0/7.0 2.1/2.1 3.3 2.5 CDS10060-DV 17.5 5.3 12 3.7 30 849.6 10.0/6.0 3.0/1.8 5.0 or 10.2 3.8 or 7.8 CDS10080-DV 17.5 5.3 14 4.3 50 1416.0 10.0/8.0 3.0/2.4 5.0 or 10.2 3.8 or 7.8 CDS100100-DV 17.5 5.3 16 4.9 64 1812.5 10.0/10.0 3.0/3.0 5.0 or 10.2 3.8 or 7.8 CDS150134-DC 22 6.7** 22 6.7** 148 4191.4 15.0/13.4 4.6/4.1 20.4 15.6 CDS200164-DC 26 7.9** 26 7.9** 270 7646.6 20.0/16.4 6.1/5.0 20.4 15.6 CDS240160-DC 32 9.8** 25 7.6** 300 8496.2 24.0/16.0 7.3/4.9 20.4 15.6 Cast In Place InlineOfflineOfflinePrecast****Sump Capacities and Depth Below Pipe Invert can vary due to specific site design Vortechs Swirl Chamber Internal Water Quality Flow1 Peak Sediment Model Diameter Length cfs / L/s Treatment Flow2 Storage ft m ft m 50 µm 110 µm 200 µm cfs L/s yd3 m3 1000 3 0.9 9 2.7 0.21/5.9 0.59/16.7 0.98/27.8 1.6 45.3 0.7 0.5 2000 4 1.2 10 3.0 0.36/10.2 1.0/28.3 1.7/48.1 2.8 79.3 1.2 0.9 3000 5 1.5 11 3.4 0.59/16.7 1.7/48.1 2.7/76.5 4.5 127.4 1.8 1.4 4000 6 1.8 12 3.7 0.78/22.1 2.2/62.3 3.7/104.8 6.0 169.9 2.4 1.8 5000 7 2.1 13 4.0 1.1/31.1 3.1/87.8 5.2/147.2 8.5 240.7 3.2 2.4 7000 8 2.4 14 4.3 1.4/39.6 4.1/116.1 6.7/189.7 11.0 311.5 4.0 3.1 9000 9 2.7 15 4.6 1.8/51.0 5.2/147.2 8.5/240.7 14.0 396.4 4.8 3.7 11000 10 3.0 16 4.9 2.3/65.1 6.5/184.1 10.7/303.0 17.5 495.5 5.6 4.3 16000 12 3.7 18 5.5 3.3/93.4 9.3/263.3 15.3/433.2 25.0 707.9 7.1 5.4 1. Water Quality Flow Rates are based on 80% removal for the particle size distributions (PSD) listed above with d50 = 50, 110 & 200-µm. Particle size should be chosen based on anticipated sediment load. 2. Peak Treatment Flow is maximum flow treated for each unit listed. This flow represents an infrequent storm event such as a 10 or 25 yr storm. Standard Vortechs System depth below invert is 3’ for all precast models. Cast-in-place system are available to treat higher flows. Check with your local representatives for specifications. page 6 page 7 * Denotes models may not be manufactured in your area. Check with your local representative for availability. 1. Water Quality Flow is based on 80% removal of a particle size distribution with an average particle size of 110-µm. This flow also represents the maximum flow prior to which bypass occurs. VortSentry Swirl Chamber Typical Depth Water Quality Flow1 Max. Size Sediment Model Diameter Below Invert 110 µm Inlet/Outlet Storage ft m ft m cfs L/s in mm yd3 m3 VS30* 3 0.9 5.8 1.8 0.26 7.4 12 300 0.8 0.6 VS40 4 1.2 7.0 2.1 0.58 16.4 18 460 1.4 1.1 VS50* 5 1.5 8.0 2.4 1.1 31.1 18 460 2.2 1.7 VS60 6 1.8 8.9 2.7 1.8 51.0 24 600 3.1 2.4 VS70* 7 2.1 9.7 3.0 2.7 76.5 30 750 4.3 3.3 VS80 8 2.4 10.1 3.1 3.9 110.4 36 600 5.6 4.3 VortSentry HS Swirl Chamber Typical Depth Water Quality Flow1 Max. Size Sediment Model Diameter Below Invert 240 µm Inlet/Outlet Storage ft m ft m cfs L/s in mm yd3 m3 HS36* 3 0.9 5.6 1.7 0.55 15.6 18 460 0.5 0.4 HS48 4 1.2 6.8 2.1 1.2 34.0 24 600 0.9 0.7 HS60* 5 1.5 8.0 2.4 2.2 62.3 30 760 1.5 1.1 HS72 6 1.8 9.2 2.8 3.7 104.8 36 900 2.1 1.6 HS84* 7 2.1 10.4 3.2 5.6 158.6 42 1050 2.8 2.1 HS96 8 2.4 11.5 3.5 8.1 229.4 48 1200 3.7 2.8 * Models may not be manufactured in your area. Check with your local representative for availability. 1. Water Quality Flow is based on 80% removal of a particle size distribution with an average particle size of 240-µm. This flow also represents the maximum flow prior to which bypass occurs. Notes: Systems can be sized based on a water quality flow (e.g. 1 inch storm) or on a net annual basis depending on the local regulatory requirement. When sizing based on a water quality storm, the required flow to be treated should be equal or less than the listed water quality flow for the selected system. Systems sized based on a water quality storm are generally more conservatively sized. Additional particle size distributions are available for sizing purposes upon request. Depth below invert is measured to the inside bottom of the system. This depth can be adjusted to meet specific storage or maintenance requirements. Contact our support staff for the most cost effective sizing for your area. Customer Support Installation CONTECH Stormwater Solutions’ products are some of the easiest to install in the industry. We provide comprehensive installation drawings, details and instructions, as well as full technical support on every project. Maintenance Maintenance of CONTECH Stormwater Solutions products is cost effective, straightforward and efficient. We offer a complete range of engineering planning, design and drawing, and construction services that can be tailored to your specific site needs. 800.338.1122 contech-cpi.com ©2008 CONTECH Construction Products CONTECH Construction Products Inc is your single source for hassle-free specifying and purchasing of comprehensive site solutions. CONTECH’s portfolio includes bridges, drainage, erosion control, retaining wall, sanitary sewer, soil stabilization and stormwater solutions. Nothing in this catalog should be construed as an expressed warranty or an implied warranty of merchantability or fitness for any particular purpose. See the CONTECH standard quotation or acknowledgement for applicable warranties and other terms and conditions of sale. PROJECT #SHEET #OF:PAGE #OF: MADE BY: DATE: PROJECT:CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: 1 2 The Water Quality Peak Flow calculations in accordance with Appendix B of the August 2015 NYSDEC Stormwater 3 Management Design Manual for the purposes of sizing diversion or off-line structures. 4 5 Using the water quality volume (WQv), a corresponding Curve Number (CN) is computed utilizing the following equation: 6 7 CN = 1000 / [10 + 5P + 10Q - 10(Q^2 + 1.25 QP)^1/2] 8 9 Where P = rainfall, in inches (use the 90% rainfall event from Figure 4.1 for the Water Quailty Storm) 10 Q = runoff, in inches 11 12 P = inch for Saratoga County 13 Q = WQv in cf = inches 14 Watershed Area in sf 15 16 CN = 17 18 Once a CN is computed, the time of concentration (tc) is computed using guidance provided in TR-55. 19 20 The tc for this watershed is hrs 21 22 Using the computed CN, tc, and drainage area (A) in acres, the peak discharge (Qp) for the water quailty storm event 23 is computed (either Type II or Type III in the state of New York) 24 25 Read initial abstraction (Ia), compute Ia / P 26 Read the unit peak discharge (qu) for appropriate tc 27 Using the water quality volume (WQv), compute the peak discharge (Qp) 28 29 Qp = qu x A x WQv 30 31 Where Qp = the peak discharge, in cfs 32 qu = the unit peak discharge, in cfs/sq mi/inch 33 A = drainage area, in square miles 34 WQv = Water Quality Volume, in watershed inches 35 36 qu = csm/in 37 A = acres, or square miles 38 WQv =acft or watershed inches 39 40 Qp =cfs 41 42 43 44 45 46 47 48 49 50 51 52 95 0.80 0.10 1000 0.71 0.0011 0.0427 0.7 30725 Staion Park Subdivision Water Quality Peak Flow Calculations Post Development Area #1A 1,860 0.73 1.2 JWE 6/9/2024 2022-02 1 1 1 PROJECT #SHEET #OF:PAGE #OF: MADE BY: DATE: PROJECT:CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: 1 2 The Water Quality Peak Flow calculations in accordance with Appendix B of the August 2015 NYSDEC Stormwater 3 Management Design Manual for the purposes of sizing diversion or off-line structures. 4 5 Using the water quality volume (WQv), a corresponding Curve Number (CN) is computed utilizing the following equation: 6 7 CN = 1000 / [10 + 5P + 10Q - 10(Q^2 + 1.25 QP)^1/2] 8 9 Where P = rainfall, in inches (use the 90% rainfall event from Figure 4.1 for the Water Quailty Storm) 10 Q = runoff, in inches 11 12 P = inch for Saratoga County 13 Q = WQv in cf = inches 14 Watershed Area in sf 15 16 CN = 17 18 Once a CN is computed, the time of concentration (tc) is computed using guidance provided in TR-55. 19 20 The tc for this watershed is hrs 21 22 Using the computed CN, tc, and drainage area (A) in acres, the peak discharge (Qp) for the water quailty storm event 23 is computed (either Type II or Type III in the state of New York) 24 25 Read initial abstraction (Ia), compute Ia / P 26 Read the unit peak discharge (qu) for appropriate tc 27 Using the water quality volume (WQv), compute the peak discharge (Qp) 28 29 Qp = qu x A x WQv 30 31 Where Qp = the peak discharge, in cfs 32 qu = the unit peak discharge, in cfs/sq mi/inch 33 A = drainage area, in square miles 34 WQv = Water Quality Volume, in watershed inches 35 36 qu = csm/in 37 A = acres, or square miles 38 WQv =acft or watershed inches 39 40 Qp =cfs 41 42 43 44 45 46 47 48 49 50 51 52 97 13.80 0.30 800 12.90 0.0202 0.92 0.9 561846 Staion Park Subdivision Water Quality Peak Flow Calculations Post Development Area #2 40,075 0.86 1.2 JWE 6/9/2024 2022-02 1 1 1 PROJECT #SHEET #OF:PAGE #OF: MADE BY: DATE: PROJECT:CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: 1 2 The Water Quality Peak Flow calculations in accordance with Appendix B of the August 2015 NYSDEC Stormwater 3 Management Design Manual for the purposes of sizing diversion or off-line structures. 4 5 Using the water quality volume (WQv), a corresponding Curve Number (CN) is computed utilizing the following equation: 6 7 CN = 1000 / [10 + 5P + 10Q - 10(Q^2 + 1.25 QP)^1/2] 8 9 Where P = rainfall, in inches (use the 90% rainfall event from Figure 4.1 for the Water Quailty Storm) 10 Q = runoff, in inches 11 12 P = inch for Saratoga County 13 Q = WQv in cf = inches 14 Watershed Area in sf 15 16 CN = 17 18 Once a CN is computed, the time of concentration (tc) is computed using guidance provided in TR-55. 19 20 The tc for this watershed is hrs 21 22 Using the computed CN, tc, and drainage area (A) in acres, the peak discharge (Qp) for the water quailty storm event 23 is computed (either Type II or Type III in the state of New York) 24 25 Read initial abstraction (Ia), compute Ia / P 26 Read the unit peak discharge (qu) for appropriate tc 27 Using the water quality volume (WQv), compute the peak discharge (Qp) 28 29 Qp = qu x A x WQv 30 31 Where Qp = the peak discharge, in cfs 32 qu = the unit peak discharge, in cfs/sq mi/inch 33 A = drainage area, in square miles 34 WQv = Water Quality Volume, in watershed inches 35 36 qu = csm/in 37 A = acres, or square miles 38 WQv =acft or watershed inches 39 40 Qp =cfs 41 42 43 44 45 46 47 48 49 50 51 52 95 3.96 0.10 1000 3.55 0.0055 0.21109 0.7 154702 Staion Park Subdivision Water Quality Peak Flow Calculations Post Development Area #3 9,195 0.71 1.2 JWE 6/9/2024 2022-02 1 1 1 Stormwater Management Report July 2024 Page 19 Exhibit C – Hydrologic Model Simulation Using TR-55 Tabular Method .1 Routing Tables for the 1, 2, 10, 25, 50 and 100 year storms with Inflow and Outflow Hydrographs 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 Watershed Model Schematic Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Project: Saratoga Station (7-11-24).gpw Monday, 07 / 15 / 2024 Hyd.Origin Description Legend 1 SCS Runoff Pre Area #1 2 SCS Runoff Pre Area #2 3 SCS Runoff Pre Area #3 4 SCS Runoff Post Area #1 5 SCS Runoff Post Area #1A 6 SCS Runoff Post Area #2 7 SCS Runoff Post Area #3 8 SCS Runoff Post Area #3A 9 Reservoir Route STMH#7 10 Diversion1 Flow to WQv#2 11 Diversion2 High flow to Array 12 Combine Flow to Array #1 13 Reservoir Route Array #1 14 Reservoir Route Basin #1 15 Reservoir Route Wet Swale #1 Hydraflow Table of Contents Saratoga Station (7-11-24).gpw Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Watershed Model Schematic...................................................................................... 1 Hydrograph Return Period Recap............................................................................. 2 1 - Year Summary Report......................................................................................................................... 3 Hydrograph Reports................................................................................................................... 4 Hydrograph No. 1, SCS Runoff, Pre Area #1.......................................................................... 4 TR-55 Tc Worksheet............................................................................................................ 5 Hydrograph No. 2, SCS Runoff, Pre Area #2........................................................................... 6 TR-55 Tc Worksheet............................................................................................................ 7 Hydrograph No. 3, SCS Runoff, Pre Area #3........................................................................... 8 TR-55 Tc Worksheet............................................................................................................ 9 Hydrograph No. 4, SCS Runoff, Post Area #1....................................................................... 10 TR-55 Tc Worksheet.......................................................................................................... 11 Hydrograph No. 5, SCS Runoff, Post Area #1A..................................................................... 12 Hydrograph No. 6, SCS Runoff, Post Area #2....................................................................... 13 TR-55 Tc Worksheet.......................................................................................................... 14 Hydrograph No. 7, SCS Runoff, Post Area #3....................................................................... 15 TR-55 Tc Worksheet.......................................................................................................... 16 Hydrograph No. 8, SCS Runoff, Post Area #3A..................................................................... 17 Hydrograph No. 9, Reservoir, Route STMH#7....................................................................... 18 Pond Report - STMH#7..................................................................................................... 19 Hydrograph No. 10, Diversion1, Flow to WQv#2................................................................... 20 Hydrograph No. 11, Diversion2, High flow to Array................................................................ 21 Hydrograph No. 12, Combine, Flow to Array #1..................................................................... 22 Hydrograph No. 13, Reservoir, Route Array #1...................................................................... 23 Pond Report - Infiltration Array #1..................................................................................... 24 Hydrograph No. 14, Reservoir, Route Basin #1..................................................................... 25 Pond Report - Basin #1.................................................................................................... 26 Hydrograph No. 15, Reservoir, Route Wet Swale #1............................................................. 27 Pond Report - Wet Swale #1............................................................................................. 28 2 - Year Summary Report....................................................................................................................... 29 Hydrograph Reports................................................................................................................. 30 Hydrograph No. 1, SCS Runoff, Pre Area #1........................................................................ 30 Hydrograph No. 2, SCS Runoff, Pre Area #2......................................................................... 31 Hydrograph No. 3, SCS Runoff, Pre Area #3......................................................................... 32 Hydrograph No. 4, SCS Runoff, Post Area #1....................................................................... 33 Hydrograph No. 5, SCS Runoff, Post Area #1A..................................................................... 34 Hydrograph No. 6, SCS Runoff, Post Area #2....................................................................... 35 Hydrograph No. 7, SCS Runoff, Post Area #3....................................................................... 36 Hydrograph No. 8, SCS Runoff, Post Area #3A..................................................................... 37 Hydrograph No. 9, Reservoir, Route STMH#7....................................................................... 38 Hydrograph No. 10, Diversion1, Flow to WQv#2................................................................... 39 Hydrograph No. 11, Diversion2, High flow to Array................................................................ 40 Hydrograph No. 12, Combine, Flow to Array #1..................................................................... 41 Contents continued...Saratoga Station (7-11-24).gpw Hydrograph No. 13, Reservoir, Route Array #1...................................................................... 42 Hydrograph No. 14, Reservoir, Route Basin #1..................................................................... 43 Hydrograph No. 15, Reservoir, Route Wet Swale #1............................................................. 44 10 - Year Summary Report....................................................................................................................... 45 Hydrograph Reports................................................................................................................. 46 Hydrograph No. 1, SCS Runoff, Pre Area #1........................................................................ 46 Hydrograph No. 2, SCS Runoff, Pre Area #2......................................................................... 47 Hydrograph No. 3, SCS Runoff, Pre Area #3......................................................................... 48 Hydrograph No. 4, SCS Runoff, Post Area #1....................................................................... 49 Hydrograph No. 5, SCS Runoff, Post Area #1A..................................................................... 50 Hydrograph No. 6, SCS Runoff, Post Area #2....................................................................... 51 Hydrograph No. 7, SCS Runoff, Post Area #3....................................................................... 52 Hydrograph No. 8, SCS Runoff, Post Area #3A..................................................................... 53 Hydrograph No. 9, Reservoir, Route STMH#7....................................................................... 54 Hydrograph No. 10, Diversion1, Flow to WQv#2................................................................... 55 Hydrograph No. 11, Diversion2, High flow to Array................................................................ 56 Hydrograph No. 12, Combine, Flow to Array #1..................................................................... 57 Hydrograph No. 13, Reservoir, Route Array #1...................................................................... 58 Hydrograph No. 14, Reservoir, Route Basin #1..................................................................... 59 Hydrograph No. 15, Reservoir, Route Wet Swale #1............................................................. 60 25 - Year Summary Report....................................................................................................................... 61 Hydrograph Reports................................................................................................................. 62 Hydrograph No. 1, SCS Runoff, Pre Area #1........................................................................ 62 Hydrograph No. 2, SCS Runoff, Pre Area #2......................................................................... 63 Hydrograph No. 3, SCS Runoff, Pre Area #3......................................................................... 64 Hydrograph No. 4, SCS Runoff, Post Area #1....................................................................... 65 Hydrograph No. 5, SCS Runoff, Post Area #1A..................................................................... 66 Hydrograph No. 6, SCS Runoff, Post Area #2....................................................................... 67 Hydrograph No. 7, SCS Runoff, Post Area #3....................................................................... 68 Hydrograph No. 8, SCS Runoff, Post Area #3A..................................................................... 69 Hydrograph No. 9, Reservoir, Route STMH#7....................................................................... 70 Hydrograph No. 10, Diversion1, Flow to WQv#2................................................................... 71 Hydrograph No. 11, Diversion2, High flow to Array................................................................ 72 Hydrograph No. 12, Combine, Flow to Array #1..................................................................... 73 Hydrograph No. 13, Reservoir, Route Array #1...................................................................... 74 Hydrograph No. 14, Reservoir, Route Basin #1..................................................................... 75 Hydrograph No. 15, Reservoir, Route Wet Swale #1............................................................. 76 50 - Year Summary Report....................................................................................................................... 77 Hydrograph Reports................................................................................................................. 78 Hydrograph No. 1, SCS Runoff, Pre Area #1........................................................................ 78 Hydrograph No. 2, SCS Runoff, Pre Area #2......................................................................... 79 Hydrograph No. 3, SCS Runoff, Pre Area #3......................................................................... 80 Hydrograph No. 4, SCS Runoff, Post Area #1....................................................................... 81 Hydrograph No. 5, SCS Runoff, Post Area #1A..................................................................... 82 Contents continued...Saratoga Station (7-11-24).gpw Hydrograph No. 6, SCS Runoff, Post Area #2....................................................................... 83 Hydrograph No. 7, SCS Runoff, Post Area #3....................................................................... 84 Hydrograph No. 8, SCS Runoff, Post Area #3A..................................................................... 85 Hydrograph No. 9, Reservoir, Route STMH#7....................................................................... 86 Hydrograph No. 10, Diversion1, Flow to WQv#2................................................................... 87 Hydrograph No. 11, Diversion2, High flow to Array................................................................ 88 Hydrograph No. 12, Combine, Flow to Array #1..................................................................... 89 Hydrograph No. 13, Reservoir, Route Array #1...................................................................... 90 Hydrograph No. 14, Reservoir, Route Basin #1..................................................................... 91 Hydrograph No. 15, Reservoir, Route Wet Swale #1............................................................. 92 100 - Year Summary Report....................................................................................................................... 93 Hydrograph Reports................................................................................................................. 94 Hydrograph No. 1, SCS Runoff, Pre Area #1........................................................................ 94 Hydrograph No. 2, SCS Runoff, Pre Area #2......................................................................... 95 Hydrograph No. 3, SCS Runoff, Pre Area #3......................................................................... 96 Hydrograph No. 4, SCS Runoff, Post Area #1....................................................................... 97 Hydrograph No. 5, SCS Runoff, Post Area #1A..................................................................... 98 Hydrograph No. 6, SCS Runoff, Post Area #2....................................................................... 99 Hydrograph No. 7, SCS Runoff, Post Area #3..................................................................... 100 Hydrograph No. 8, SCS Runoff, Post Area #3A................................................................... 101 Hydrograph No. 9, Reservoir, Route STMH#7..................................................................... 102 Hydrograph No. 10, Diversion1, Flow to WQv#2................................................................. 103 Hydrograph No. 11, Diversion2, High flow to Array.............................................................. 104 Hydrograph No. 12, Combine, Flow to Array #1................................................................... 105 Hydrograph No. 13, Reservoir, Route Array #1.................................................................... 106 Hydrograph No. 14, Reservoir, Route Basin #1................................................................... 107 Hydrograph No. 15, Reservoir, Route Wet Swale #1........................................................... 108 IDF Report................................................................................................................ 109 Hydrograph Return Period Recap 2 Hyd. Hydrograph Inflow Peak Outflow (cfs)Hydrograph No. type hyd(s)Description (origin) 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr 1 SCS Runoff ------ 0.000 0.000 ------- ------- 0.000 0.000 0.007 0.023 Pre Area #1 2 SCS Runoff ------ 0.000 0.000 ------- ------- 0.000 0.003 0.044 0.139 Pre Area #2 3 SCS Runoff ------ 0.000 0.000 ------- ------- 0.000 0.035 0.115 0.485 Pre Area #3 4 SCS Runoff ------ 0.000 0.000 ------- ------- 0.000 0.000 0.006 0.018 Post Area #1 5 SCS Runoff ------ 0.575 0.848 ------- ------- 1.742 2.480 3.200 4.074 Post Area #1A 6 SCS Runoff ------ 8.320 11.68 ------- ------- 22.50 31.32 39.65 49.56 Post Area #2 7 SCS Runoff ------ 0.000 0.000 ------- ------- 0.006 0.029 0.120 0.421 Post Area #3 8 SCS Runoff ------ 3.156 4.569 ------- ------- 9.168 12.94 16.64 21.08 Post Area #3A 9 Reservoir 6 8.327 11.67 ------- ------- 22.51 31.33 39.65 49.56 Route STMH#7 10 Diversion1 9 7.521 8.937 ------- ------- 11.89 13.22 14.17 15.36 Flow to WQv#2 11 Diversion2 9 0.805 2.732 ------- ------- 10.62 18.12 25.48 34.20 High flow to Array 12 Combine 10, 11 8.327 11.67 ------- ------- 22.51 31.33 39.65 49.56 Flow to Array #1 13 Reservoir 12 0.000 0.000 ------- ------- 0.000 0.000 0.000 0.000 Route Array #1 14 Reservoir 8 0.000 0.000 ------- ------- 0.000 0.000 0.000 0.000 Route Basin #1 15 Reservoir 5 0.000 0.000 ------- ------- 0.000 0.000 0.000 0.000 Route Wet Swale #1 Proj. file: Saratoga Station (7-11-24).gpw Monday, 07 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph Summary Report 3 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Pre Area #1 2 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Pre Area #2 3 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Pre Area #3 4 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Post Area #1 5 SCS Runoff 0.575 2 718 1,197 ------ ------ ------ Post Area #1A 6 SCS Runoff 8.320 2 730 32,609 ------ ------ ------ Post Area #2 7 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Post Area #3 8 SCS Runoff 3.156 2 718 6,491 ------ ------ ------ Post Area #3A 9 Reservoir 8.327 2 730 32,609 6 321.42 7.70 Route STMH#7 10 Diversion1 7.521 2 730 32,115 9 ------ ------ Flow to WQv#2 11 Diversion2 0.805 2 730 494 9 ------ ------ High flow to Array 12 Combine 8.327 2 730 32,609 10, 11 ------ ------ Flow to Array #1 13 Reservoir 0.000 2 728 0 12 319.02 45.5 Route Array #1 14 Reservoir 0.000 2 n/a 0 8 319.35 469 Route Basin #1 15 Reservoir 0.000 2 732 0 5 320.18 277 Route Wet Swale #1 Saratoga Station (7-11-24).gpw Return Period: 1 Year Monday, 07 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 1 Pre Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 1 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 2.415 ac Curve number = 30 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 29.30 min Total precip. = 2.23 in Distribution = Type II Storm duration = 24 hrs Shape factor = 600 4 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #1 Hyd. No. 1 -- 1 Year Hyd No. 1 TR55 Tc Worksheet 5 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hyd. No. 1 Pre Area #1 Description A B C Totals Sheet Flow Manning's n-value = 0.400 0.011 0.011 Flow length (ft) = 150.0 0.0 0.0 Two-year 24-hr precip. (in) = 2.61 0.00 0.00 Land slope (%) = 3.00 0.00 0.00 Travel Time (min) = 27.96 + 0.00 + 0.00 = 27.96 Shallow Concentrated Flow Flow length (ft) = 119.00 0.00 0.00 Watercourse slope (%) = 1.60 0.00 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =2.04 0.00 0.00 Travel Time (min) = 0.97 + 0.00 + 0.00 = 0.97 Channel Flow X sectional flow area (sqft) = 20.00 0.00 0.00 Wetted perimeter (ft) = 10.00 0.00 0.00 Channel slope (%) = 0.50 0.00 0.00 Manning's n-value = 0.040 0.015 0.015 Velocity (ft/s) =4.19 0.00 0.00 Flow length (ft) ({0})102.0 0.0 0.0 Travel Time (min) = 0.41 + 0.00 + 0.00 = 0.41 Total Travel Time, Tc .............................................................................. 29.30 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 2 Pre Area #2 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 1 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 10.554 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 49.40 min Total precip. = 2.23 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 6 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #2 Hyd. No. 2 -- 1 Year Hyd No. 2 TR55 Tc Worksheet 7 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hyd. No. 2 Pre Area #2 Description A B C Totals Sheet Flow Manning's n-value = 0.400 0.011 0.011 Flow length (ft) = 150.0 0.0 0.0 Two-year 24-hr precip. (in) = 2.61 0.00 0.00 Land slope (%) = 1.00 0.00 0.00 Travel Time (min) = 43.40 + 0.00 + 0.00 = 43.40 Shallow Concentrated Flow Flow length (ft) = 452.00 0.00 0.00 Watercourse slope (%) = 0.60 0.00 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =1.25 0.00 0.00 Travel Time (min) = 6.03 + 0.00 + 0.00 = 6.03 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =0.00 0.00 0.00 Flow length (ft) ({0})0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc .............................................................................. 49.40 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 3 Pre Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 1 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 8.479 ac Curve number = 35 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 2.23 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 8 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #3 Hyd. No. 3 -- 1 Year Hyd No. 3 TR55 Tc Worksheet 9 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hyd. No. 3 Pre Area #3 Description A B C Totals Sheet Flow Manning's n-value = 0.400 0.011 0.011 Flow length (ft) = 150.0 0.0 0.0 Two-year 24-hr precip. (in) = 2.61 0.00 0.00 Land slope (%) = 4.00 0.00 0.00 Travel Time (min) = 24.92 + 0.00 + 0.00 = 24.92 Shallow Concentrated Flow Flow length (ft) = 455.00 0.00 0.00 Watercourse slope (%) = 0.80 0.00 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =1.44 0.00 0.00 Travel Time (min) = 5.25 + 0.00 + 0.00 = 5.25 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =0.00 0.00 0.00 Flow length (ft) ({0})0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc .............................................................................. 30.20 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 4 Post Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 1 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 1.337 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 28.60 min Total precip. = 2.23 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 10 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Post Area #1 Hyd. No. 4 -- 1 Year Hyd No. 4 TR55 Tc Worksheet 11 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hyd. No. 4 Post Area #1 Description A B C Totals Sheet Flow Manning's n-value = 0.400 0.011 0.011 Flow length (ft) = 150.0 0.0 0.0 Two-year 24-hr precip. (in) = 2.61 0.00 0.00 Land slope (%) = 3.00 0.00 0.00 Travel Time (min) = 27.96 + 0.00 + 0.00 = 27.96 Shallow Concentrated Flow Flow length (ft) = 30.00 0.00 0.00 Watercourse slope (%) = 1.60 0.00 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =2.04 0.00 0.00 Travel Time (min) = 0.24 + 0.00 + 0.00 = 0.24 Channel Flow X sectional flow area (sqft) = 20.00 0.00 0.00 Wetted perimeter (ft) = 10.00 0.00 0.00 Channel slope (%) = 0.50 0.00 0.00 Manning's n-value = 0.040 0.015 0.015 Velocity (ft/s) =4.19 0.00 0.00 Flow length (ft) ({0})102.0 0.0 0.0 Travel Time (min) = 0.41 + 0.00 + 0.00 = 0.41 Total Travel Time, Tc .............................................................................. 28.60 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 5 Post Area #1A Hydrograph type = SCS Runoff Peak discharge = 0.575 cfs Storm frequency = 1 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 1,197 cuft Drainage area = 0.705 ac Curve number = 75 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 2.23 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 12 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (hrs) Post Area #1A Hyd. No. 5 -- 1 Year Hyd No. 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 6 Post Area #2 Hydrograph type = SCS Runoff Peak discharge = 8.320 cfs Storm frequency = 1 yrs Time to peak = 12.17 hrs Time interval = 2 min Hyd. volume = 32,609 cuft Drainage area = 12.898 ac Curve number = 80 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 24.40 min Total precip. = 2.23 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 13 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (hrs) Post Area #2 Hyd. No. 6 -- 1 Year Hyd No. 6 TR55 Tc Worksheet 14 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hyd. No. 6 Post Area #2 Description A B C Totals Sheet Flow Manning's n-value = 0.240 0.011 0.011 Flow length (ft) = 100.0 0.0 0.0 Two-year 24-hr precip. (in) = 2.61 0.00 0.00 Land slope (%) = 1.00 0.00 0.00 Travel Time (min) = 20.85 + 0.00 + 0.00 = 20.85 Shallow Concentrated Flow Flow length (ft) = 266.00 0.00 0.00 Watercourse slope (%) = 1.00 0.00 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =1.61 0.00 0.00 Travel Time (min) = 2.75 + 0.00 + 0.00 = 2.75 Channel Flow X sectional flow area (sqft) = 0.78 0.00 0.00 Wetted perimeter (ft) = 1.00 0.00 0.00 Channel slope (%) = 0.60 0.00 0.00 Manning's n-value = 0.012 0.015 0.015 Velocity (ft/s) =8.14 0.00 0.00 Flow length (ft) ({0})400.0 0.0 0.0 Travel Time (min) = 0.82 + 0.00 + 0.00 = 0.82 Total Travel Time, Tc .............................................................................. 24.40 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 7 Post Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 1 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 3.008 ac Curve number = 38 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 2.23 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 15 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Post Area #3 Hyd. No. 7 -- 1 Year Hyd No. 7 TR55 Tc Worksheet 16 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hyd. No. 7 Post Area #3 Description A B C Totals Sheet Flow Manning's n-value = 0.400 0.011 0.011 Flow length (ft) = 150.0 0.0 0.0 Two-year 24-hr precip. (in) = 2.61 0.00 0.00 Land slope (%) = 4.00 0.00 0.00 Travel Time (min) = 24.92 + 0.00 + 0.00 = 24.92 Shallow Concentrated Flow Flow length (ft) = 455.00 0.00 0.00 Watercourse slope (%) = 0.80 0.00 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =1.44 0.00 0.00 Travel Time (min) = 5.25 + 0.00 + 0.00 = 5.25 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =0.00 0.00 0.00 Flow length (ft) ({0})0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc .............................................................................. 30.20 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 8 Post Area #3A Hydrograph type = SCS Runoff Peak discharge = 3.156 cfs Storm frequency = 1 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 6,491 cuft Drainage area = 3.551 ac Curve number = 76 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 2.23 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 17 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 Q (cfs) Time (hrs) Post Area #3A Hyd. No. 8 -- 1 Year Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 9 Route STMH#7 Hydrograph type = Reservoir Peak discharge = 8.327 cfs Storm frequency = 1 yrs Time to peak = 12.17 hrs Time interval = 2 min Hyd. volume = 32,609 cuft Inflow hyd. No. = 6 - Post Area #2 Max. Elevation = 321.42 ft Reservoir name = STMH#7 Max. Storage = 8 cuft Storage Indication method used. 18 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (hrs) Route STMH#7 Hyd. No. 9 -- 1 Year Hyd No. 9 Hyd No. 6 Total storage used = 8 cuft Pond Report 19 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Pond No. 4 - STMH#7 Pond Data Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 319.50 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 319.50 04 0 0 1.00 320.50 04 4 4 2.00 321.50 04 4 8 3.00 322.50 04 4 12 4.00 323.50 04 4 16 5.00 324.50 04 4 20 6.00 325.50 04 4 24 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 18.00 24.00 0.00 0.00 Span (in)= 18.00 38.00 0.00 0.00 No. Barrels = 1 1 0 0 Invert El. (ft)= 319.50 321.25 0.00 0.00 Length (ft)= 24.00 30.00 0.00 0.00 Slope (%)= 0.50 5.80 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 0.00 0.00 0.00 0.00 Crest El. (ft)= 0.00 0.00 0.00 0.00 Weir Coeff.= 2.60 3.33 3.33 3.33 Weir Type = Broad --- --- --- Multi-Stage = No No No No Exfil.(in/hr)= 0.000 (by Contour) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). 0.00 8.00 16.00 24.00 32.00 40.00 48.00 56.00 64.00 72.00 80.00 Stage (ft) 0.00 319.50 1.00 320.50 2.00 321.50 3.00 322.50 4.00 323.50 5.00 324.50 6.00 325.50 Elev (ft) Discharge (cfs) Stage / Discharge Total Q Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 10 Flow to WQv#2 Hydrograph type = Diversion1 Peak discharge = 7.521 cfs Storm frequency = 1 yrs Time to peak = 12.17 hrs Time interval = 2 min Hyd. volume = 32,115 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 11 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 20 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (hrs) Flow to WQv#2 Hyd. No. 10 -- 1 Year Hyd No. 10 -- Pond outlet Hyd No. 9 -- Inflow Hyd No. 11 -- 9 minus 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 11 High flow to Array Hydrograph type = Diversion2 Peak discharge = 0.805 cfs Storm frequency = 1 yrs Time to peak = 12.17 hrs Time interval = 2 min Hyd. volume = 494 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 10 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 21 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (hrs) High flow to Array Hyd. No. 11 -- 1 Year Hyd No. 11 -- Qin - Pond outlet Hyd No. 9 -- Inflow Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 12 Flow to Array #1 Hydrograph type = Combine Peak discharge = 8.327 cfs Storm frequency = 1 yrs Time to peak = 12.17 hrs Time interval = 2 min Hyd. volume = 32,609 cuft Inflow hyds. = 10, 11 Contrib. drain. area = 0.000 ac 22 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (hrs) Flow to Array #1 Hyd. No. 12 -- 1 Year Hyd No. 12 Hyd No. 10 Hyd No. 11 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 13 Route Array #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 1 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 12 - Flow to Array #1 Max. Elevation = 319.02 ft Reservoir name = Infiltration Array #1 Max. Storage = 45 cuft Storage Indication method used. Exfiltration extracted from Outflow. 23 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (hrs) Route Array #1 Hyd. No. 13 -- 1 Year Hyd No. 13 Hyd No. 12 Total storage used = 45 cuft Pond Report 24 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Pond No. 2 - Infiltration Array #1 Pond Data UG Chambers -Invert elev. = 319.00 ft, Rise x Span = 3.00 x 3.00 ft, Barrel Len = 180.00 ft, No. Barrels = 4, Slope = 0.00%, Headers = Yes Encasement -Invert elev. = 319.00 ft, Width = 10.00 ft, Height = 7.00 ft, Voids = 20.00% Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 319.00 n/a 0 0 0.70 319.70 n/a 1,923 1,923 1.40 320.40 n/a 2,389 4,312 2.10 321.10 n/a 2,432 6,744 2.80 321.80 n/a 2,132 8,876 3.50 322.50 n/a 1,250 10,126 4.20 323.20 n/a 1,120 11,246 4.90 323.90 n/a 1,120 12,366 5.60 324.60 n/a 1,120 13,486 6.30 325.30 n/a 1,120 14,607 7.00 326.00 n/a 1,120 15,727 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 12.00 0.00 0.00 0.00 Span (in)= 12.00 0.00 0.00 0.00 No. Barrels = 1 0 0 0 Invert El. (ft)= 323.50 0.00 0.00 0.00 Length (ft)= 70.00 0.00 0.00 0.00 Slope (%)= 0.71 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 0.00 0.00 0.00 0.00 Crest El. (ft)= 0.00 0.00 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = --- --- --- --- Multi-Stage = No No No No Exfil.(in/hr)= 200.000 (by Contour) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). 0.00 4.00 8.00 12.00 16.00 20.00 24.00 28.00 32.00 36.00 40.00 Stage (ft) 0.00 319.00 1.00 320.00 2.00 321.00 3.00 322.00 4.00 323.00 5.00 324.00 6.00 325.00 7.00 326.00 Elev (ft) Discharge (cfs) Stage / Discharge Total Q Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 14 Route Basin #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 1 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 8 - Post Area #3A Max. Elevation = 319.35 ft Reservoir name = Basin #1 Max. Storage = 469 cuft Storage Indication method used. Exfiltration extracted from Outflow. 25 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 Q (cfs) Time (hrs) Route Basin #1 Hyd. No. 14 -- 1 Year Hyd No. 14 Hyd No. 8 Total storage used = 469 cuft Pond Report 26 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Pond No. 3 - Basin #1 Pond Data Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 319.00 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 319.00 1,020 0 0 1.00 320.00 1,718 1,354 1,354 2.00 321.00 2,618 2,152 3,506 3.00 322.00 3,709 3,147 6,653 4.00 323.00 4,990 4,333 10,986 5.00 324.00 6,436 5,697 16,684 6.00 325.00 7,957 7,182 23,866 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 0.00 0.00 0.00 0.00 Span (in)= 0.00 0.00 0.00 0.00 No. Barrels = 0 0 0 0 Invert El. (ft)= 0.00 0.00 0.00 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 10.00 0.00 0.00 0.00 Crest El. (ft)= 324.00 0.00 0.00 0.00 Weir Coeff.= 2.60 3.33 3.33 3.33 Weir Type = Broad --- --- --- Multi-Stage = No No No No Exfil.(in/hr)= 200.000 (by Contour) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). 0.00 6.00 12.00 18.00 24.00 30.00 36.00 42.00 48.00 54.00 60.00 66.00 Stage (ft) 0.00 319.00 1.00 320.00 2.00 321.00 3.00 322.00 4.00 323.00 5.00 324.00 6.00 325.00 Elev (ft) Discharge (cfs) Stage / Discharge Total Q Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 15 Route Wet Swale #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 1 yrs Time to peak = 12.20 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 5 - Post Area #1A Max. Elevation = 320.18 ft Reservoir name = Wet Swale #1 Max. Storage = 277 cuft Storage Indication method used. Exfiltration extracted from Outflow. 27 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (hrs) Route Wet Swale #1 Hyd. No. 15 -- 1 Year Hyd No. 15 Hyd No. 5 Total storage used = 277 cuft Pond Report 28 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Pond No. 1 - Wet Swale #1 Pond Data Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 320.00 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 320.00 938 0 0 1.00 321.00 2,313 1,574 1,574 2.00 322.00 3,189 2,739 4,314 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 0.00 0.00 0.00 0.00 Span (in)= 0.00 0.00 0.00 0.00 No. Barrels = 0 0 0 0 Invert El. (ft)= 0.00 0.00 0.00 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 10.00 0.00 0.00 0.00 Crest El. (ft)= 321.50 0.00 0.00 0.00 Weir Coeff.= 2.60 3.33 3.33 3.33 Weir Type = Broad --- --- --- Multi-Stage = No No No No Exfil.(in/hr)= 20.000 (by Contour) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 Stage (ft) 0.00 320.00 0.20 320.20 0.40 320.40 0.60 320.60 0.80 320.80 1.00 321.00 1.20 321.20 1.40 321.40 1.60 321.60 1.80 321.80 2.00 322.00 Elev (ft) Discharge (cfs) Stage / Discharge Total Q Hydrograph Summary Report 29 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Pre Area #1 2 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Pre Area #2 3 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Pre Area #3 4 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Post Area #1 5 SCS Runoff 0.848 2 718 1,717 ------ ------ ------ Post Area #1A 6 SCS Runoff 11.68 2 730 44,510 ------ ------ ------ Post Area #2 7 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Post Area #3 8 SCS Runoff 4.569 2 718 9,209 ------ ------ ------ Post Area #3A 9 Reservoir 11.67 2 730 44,510 6 321.65 8.59 Route STMH#7 10 Diversion1 8.937 2 730 42,037 9 ------ ------ Flow to WQv#2 11 Diversion2 2.732 2 730 2,472 9 ------ ------ High flow to Array 12 Combine 11.67 2 730 44,510 10, 11 ------ ------ Flow to Array #1 13 Reservoir 0.000 2 722 0 12 319.02 63.9 Route Array #1 14 Reservoir 0.000 2 n/a 0 8 319.51 685 Route Basin #1 15 Reservoir 0.000 2 768 0 5 320.27 433 Route Wet Swale #1 Saratoga Station (7-11-24).gpw Return Period: 2 Year Monday, 07 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 1 Pre Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 2.415 ac Curve number = 30 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 29.30 min Total precip. = 2.61 in Distribution = Type II Storm duration = 24 hrs Shape factor = 600 30 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #1 Hyd. No. 1 -- 2 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 2 Pre Area #2 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 10.554 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 49.40 min Total precip. = 2.61 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 31 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #2 Hyd. No. 2 -- 2 Year Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 3 Pre Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 8.479 ac Curve number = 35 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 2.61 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 32 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #3 Hyd. No. 3 -- 2 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 4 Post Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 1.337 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 28.60 min Total precip. = 2.61 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 33 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Post Area #1 Hyd. No. 4 -- 2 Year Hyd No. 4 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 5 Post Area #1A Hydrograph type = SCS Runoff Peak discharge = 0.848 cfs Storm frequency = 2 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 1,717 cuft Drainage area = 0.705 ac Curve number = 75 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 2.61 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 34 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (hrs) Post Area #1A Hyd. No. 5 -- 2 Year Hyd No. 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 6 Post Area #2 Hydrograph type = SCS Runoff Peak discharge = 11.68 cfs Storm frequency = 2 yrs Time to peak = 12.17 hrs Time interval = 2 min Hyd. volume = 44,510 cuft Drainage area = 12.898 ac Curve number = 80 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 24.40 min Total precip. = 2.61 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 35 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 Q (cfs) Time (hrs) Post Area #2 Hyd. No. 6 -- 2 Year Hyd No. 6 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 7 Post Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 3.008 ac Curve number = 38 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 2.61 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 36 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Post Area #3 Hyd. No. 7 -- 2 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 8 Post Area #3A Hydrograph type = SCS Runoff Peak discharge = 4.569 cfs Storm frequency = 2 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 9,209 cuft Drainage area = 3.551 ac Curve number = 76 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 2.61 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 37 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 5.00 5.00 Q (cfs) Time (hrs) Post Area #3A Hyd. No. 8 -- 2 Year Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 9 Route STMH#7 Hydrograph type = Reservoir Peak discharge = 11.67 cfs Storm frequency = 2 yrs Time to peak = 12.17 hrs Time interval = 2 min Hyd. volume = 44,510 cuft Inflow hyd. No. = 6 - Post Area #2 Max. Elevation = 321.65 ft Reservoir name = STMH#7 Max. Storage = 9 cuft Storage Indication method used. 38 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 Q (cfs) Time (hrs) Route STMH#7 Hyd. No. 9 -- 2 Year Hyd No. 9 Hyd No. 6 Total storage used = 9 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 10 Flow to WQv#2 Hydrograph type = Diversion1 Peak discharge = 8.937 cfs Storm frequency = 2 yrs Time to peak = 12.17 hrs Time interval = 2 min Hyd. volume = 42,037 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 11 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 39 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 Q (cfs) Time (hrs) Flow to WQv#2 Hyd. No. 10 -- 2 Year Hyd No. 10 -- Pond outlet Hyd No. 9 -- Inflow Hyd No. 11 -- 9 minus 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 11 High flow to Array Hydrograph type = Diversion2 Peak discharge = 2.732 cfs Storm frequency = 2 yrs Time to peak = 12.17 hrs Time interval = 2 min Hyd. volume = 2,472 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 10 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 40 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 Q (cfs) Time (hrs) High flow to Array Hyd. No. 11 -- 2 Year Hyd No. 11 -- Qin - Pond outlet Hyd No. 9 -- Inflow Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 12 Flow to Array #1 Hydrograph type = Combine Peak discharge = 11.67 cfs Storm frequency = 2 yrs Time to peak = 12.17 hrs Time interval = 2 min Hyd. volume = 44,510 cuft Inflow hyds. = 10, 11 Contrib. drain. area = 0.000 ac 41 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 Q (cfs) Time (hrs) Flow to Array #1 Hyd. No. 12 -- 2 Year Hyd No. 12 Hyd No. 10 Hyd No. 11 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 13 Route Array #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = 12.03 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 12 - Flow to Array #1 Max. Elevation = 319.02 ft Reservoir name = Infiltration Array #1 Max. Storage = 64 cuft Storage Indication method used. Exfiltration extracted from Outflow. 42 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 Q (cfs) Time (hrs) Route Array #1 Hyd. No. 13 -- 2 Year Hyd No. 13 Hyd No. 12 Total storage used = 64 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 14 Route Basin #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 8 - Post Area #3A Max. Elevation = 319.51 ft Reservoir name = Basin #1 Max. Storage = 685 cuft Storage Indication method used. Exfiltration extracted from Outflow. 43 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 5.00 5.00 Q (cfs) Time (hrs) Route Basin #1 Hyd. No. 14 -- 2 Year Hyd No. 14 Hyd No. 8 Total storage used = 685 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 15 Route Wet Swale #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = 12.80 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 5 - Post Area #1A Max. Elevation = 320.27 ft Reservoir name = Wet Swale #1 Max. Storage = 433 cuft Storage Indication method used. Exfiltration extracted from Outflow. 44 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (hrs) Route Wet Swale #1 Hyd. No. 15 -- 2 Year Hyd No. 15 Hyd No. 5 Total storage used = 433 cuft Hydrograph Summary Report 45 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Pre Area #1 2 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Pre Area #2 3 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Pre Area #3 4 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Post Area #1 5 SCS Runoff 1.742 2 718 3,485 ------ ------ ------ Post Area #1A 6 SCS Runoff 22.50 2 728 83,169 ------ ------ ------ Post Area #2 7 SCS Runoff 0.006 2 1440 130 ------ ------ ------ Post Area #3 8 SCS Runoff 9.168 2 718 18,364 ------ ------ ------ Post Area #3A 9 Reservoir 22.51 2 728 83,169 6 322.24 11.0 Route STMH#7 10 Diversion1 11.89 2 728 69,786 9 ------ ------ Flow to WQv#2 11 Diversion2 10.62 2 728 13,384 9 ------ ------ High flow to Array 12 Combine 22.51 2 728 83,169 10, 11 ------ ------ Flow to Array #1 13 Reservoir 0.000 2 720 0 12 319.04 123 Route Array #1 14 Reservoir 0.000 2 716 0 8 320.03 1,410 Route Basin #1 15 Reservoir 0.000 2 760 0 5 320.62 970 Route Wet Swale #1 Saratoga Station (7-11-24).gpw Return Period: 10 Year Monday, 07 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 1 Pre Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 10 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 2.415 ac Curve number = 30 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 29.30 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 600 46 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #1 Hyd. No. 1 -- 10 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 2 Pre Area #2 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 10 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 10.554 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 49.40 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 47 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #2 Hyd. No. 2 -- 10 Year Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 3 Pre Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 10 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 8.479 ac Curve number = 35 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 48 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #3 Hyd. No. 3 -- 10 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 4 Post Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 10 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 1.337 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 28.60 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 49 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Post Area #1 Hyd. No. 4 -- 10 Year Hyd No. 4 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 5 Post Area #1A Hydrograph type = SCS Runoff Peak discharge = 1.742 cfs Storm frequency = 10 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 3,485 cuft Drainage area = 0.705 ac Curve number = 75 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 50 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (hrs) Post Area #1A Hyd. No. 5 -- 10 Year Hyd No. 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 6 Post Area #2 Hydrograph type = SCS Runoff Peak discharge = 22.50 cfs Storm frequency = 10 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 83,169 cuft Drainage area = 12.898 ac Curve number = 80 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 24.40 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 51 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 Q (cfs) Time (hrs) Post Area #2 Hyd. No. 6 -- 10 Year Hyd No. 6 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 7 Post Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.006 cfs Storm frequency = 10 yrs Time to peak = 24.00 hrs Time interval = 2 min Hyd. volume = 130 cuft Drainage area = 3.008 ac Curve number = 38 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 52 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Post Area #3 Hyd. No. 7 -- 10 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 8 Post Area #3A Hydrograph type = SCS Runoff Peak discharge = 9.168 cfs Storm frequency = 10 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 18,364 cuft Drainage area = 3.551 ac Curve number = 76 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 3.71 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 53 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (hrs) Post Area #3A Hyd. No. 8 -- 10 Year Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 9 Route STMH#7 Hydrograph type = Reservoir Peak discharge = 22.51 cfs Storm frequency = 10 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 83,169 cuft Inflow hyd. No. = 6 - Post Area #2 Max. Elevation = 322.24 ft Reservoir name = STMH#7 Max. Storage = 11 cuft Storage Indication method used. 54 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 Q (cfs) Time (hrs) Route STMH#7 Hyd. No. 9 -- 10 Year Hyd No. 9 Hyd No. 6 Total storage used = 11 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 10 Flow to WQv#2 Hydrograph type = Diversion1 Peak discharge = 11.89 cfs Storm frequency = 10 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 69,786 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 11 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 55 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 Q (cfs) Time (hrs) Flow to WQv#2 Hyd. No. 10 -- 10 Year Hyd No. 10 -- Pond outlet Hyd No. 9 -- Inflow Hyd No. 11 -- 9 minus 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 11 High flow to Array Hydrograph type = Diversion2 Peak discharge = 10.62 cfs Storm frequency = 10 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 13,384 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 10 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 56 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 Q (cfs) Time (hrs) High flow to Array Hyd. No. 11 -- 10 Year Hyd No. 11 -- Qin - Pond outlet Hyd No. 9 -- Inflow Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 12 Flow to Array #1 Hydrograph type = Combine Peak discharge = 22.51 cfs Storm frequency = 10 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 83,169 cuft Inflow hyds. = 10, 11 Contrib. drain. area = 0.000 ac 57 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 Q (cfs) Time (hrs) Flow to Array #1 Hyd. No. 12 -- 10 Year Hyd No. 12 Hyd No. 10 Hyd No. 11 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 13 Route Array #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 10 yrs Time to peak = 12.00 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 12 - Flow to Array #1 Max. Elevation = 319.04 ft Reservoir name = Infiltration Array #1 Max. Storage = 123 cuft Storage Indication method used. Exfiltration extracted from Outflow. 58 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 Q (cfs) Time (hrs) Route Array #1 Hyd. No. 13 -- 10 Year Hyd No. 13 Hyd No. 12 Total storage used = 123 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 14 Route Basin #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 10 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 8 - Post Area #3A Max. Elevation = 320.03 ft Reservoir name = Basin #1 Max. Storage = 1,410 cuft Storage Indication method used. Exfiltration extracted from Outflow. 59 0.0 2.0 4.0 6.0 8.0 10.0 12.0 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (hrs) Route Basin #1 Hyd. No. 14 -- 10 Year Hyd No. 14 Hyd No. 8 Total storage used = 1,410 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 15 Route Wet Swale #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 10 yrs Time to peak = 12.67 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 5 - Post Area #1A Max. Elevation = 320.62 ft Reservoir name = Wet Swale #1 Max. Storage = 970 cuft Storage Indication method used. Exfiltration extracted from Outflow. 60 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (hrs) Route Wet Swale #1 Hyd. No. 15 -- 10 Year Hyd No. 15 Hyd No. 5 Total storage used = 970 cuft Hydrograph Summary Report 61 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 0.000 2 n/a 0 ------ ------ ------ Pre Area #1 2 SCS Runoff 0.003 2 1450 13 ------ ------ ------ Pre Area #2 3 SCS Runoff 0.035 2 1440 1,082 ------ ------ ------ Pre Area #3 4 SCS Runoff 0.000 2 1442 2 ------ ------ ------ Post Area #1 5 SCS Runoff 2.480 2 718 4,995 ------ ------ ------ Post Area #1A 6 SCS Runoff 31.32 2 728 115,020 ------ ------ ------ Post Area #2 7 SCS Runoff 0.029 2 912 1,012 ------ ------ ------ Post Area #3 8 SCS Runoff 12.94 2 716 26,124 ------ ------ ------ Post Area #3A 9 Reservoir 31.33 2 728 115,020 6 322.66 12.7 Route STMH#7 10 Diversion1 13.22 2 728 90,167 9 ------ ------ Flow to WQv#2 11 Diversion2 18.12 2 728 24,853 9 ------ ------ High flow to Array 12 Combine 31.33 2 728 115,020 10, 11 ------ ------ Flow to Array #1 13 Reservoir 0.000 2 716 0 12 319.06 171 Route Array #1 14 Reservoir 0.000 2 706 0 8 320.51 2,456 Route Basin #1 15 Reservoir 0.000 2 744 0 5 320.91 1,427 Route Wet Swale #1 Saratoga Station (7-11-24).gpw Return Period: 25 Year Monday, 07 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 1 Pre Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 25 yrs Time to peak = n/a Time interval = 2 min Hyd. volume = 0 cuft Drainage area = 2.415 ac Curve number = 30 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 29.30 min Total precip. = 4.54 in Distribution = Type II Storm duration = 24 hrs Shape factor = 600 62 0.0 0.3 0.7 1.0 1.3 1.7 2.0 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #1 Hyd. No. 1 -- 25 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 2 Pre Area #2 Hydrograph type = SCS Runoff Peak discharge = 0.003 cfs Storm frequency = 25 yrs Time to peak = 24.17 hrs Time interval = 2 min Hyd. volume = 13 cuft Drainage area = 10.554 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 49.40 min Total precip. = 4.54 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 63 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #2 Hyd. No. 2 -- 25 Year Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 3 Pre Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.035 cfs Storm frequency = 25 yrs Time to peak = 24.00 hrs Time interval = 2 min Hyd. volume = 1,082 cuft Drainage area = 8.479 ac Curve number = 35 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 4.54 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 64 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #3 Hyd. No. 3 -- 25 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 4 Post Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs Storm frequency = 25 yrs Time to peak = 24.03 hrs Time interval = 2 min Hyd. volume = 2 cuft Drainage area = 1.337 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 28.60 min Total precip. = 4.54 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 65 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Post Area #1 Hyd. No. 4 -- 25 Year Hyd No. 4 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 5 Post Area #1A Hydrograph type = SCS Runoff Peak discharge = 2.480 cfs Storm frequency = 25 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 4,995 cuft Drainage area = 0.705 ac Curve number = 75 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 4.54 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 66 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 Q (cfs) Time (hrs) Post Area #1A Hyd. No. 5 -- 25 Year Hyd No. 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 6 Post Area #2 Hydrograph type = SCS Runoff Peak discharge = 31.32 cfs Storm frequency = 25 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 115,020 cuft Drainage area = 12.898 ac Curve number = 80 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 24.40 min Total precip. = 4.54 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 67 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 5.00 5.00 10.00 10.00 15.00 15.00 20.00 20.00 25.00 25.00 30.00 30.00 35.00 35.00 Q (cfs) Time (hrs) Post Area #2 Hyd. No. 6 -- 25 Year Hyd No. 6 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 7 Post Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.029 cfs Storm frequency = 25 yrs Time to peak = 15.20 hrs Time interval = 2 min Hyd. volume = 1,012 cuft Drainage area = 3.008 ac Curve number = 38 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 4.54 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 68 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Post Area #3 Hyd. No. 7 -- 25 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 8 Post Area #3A Hydrograph type = SCS Runoff Peak discharge = 12.94 cfs Storm frequency = 25 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 26,124 cuft Drainage area = 3.551 ac Curve number = 76 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 4.54 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 69 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 14.00 14.00 Q (cfs) Time (hrs) Post Area #3A Hyd. No. 8 -- 25 Year Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 9 Route STMH#7 Hydrograph type = Reservoir Peak discharge = 31.33 cfs Storm frequency = 25 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 115,020 cuft Inflow hyd. No. = 6 - Post Area #2 Max. Elevation = 322.66 ft Reservoir name = STMH#7 Max. Storage = 13 cuft Storage Indication method used. 70 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 5.00 5.00 10.00 10.00 15.00 15.00 20.00 20.00 25.00 25.00 30.00 30.00 35.00 35.00 Q (cfs) Time (hrs) Route STMH#7 Hyd. No. 9 -- 25 Year Hyd No. 9 Hyd No. 6 Total storage used = 13 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 10 Flow to WQv#2 Hydrograph type = Diversion1 Peak discharge = 13.22 cfs Storm frequency = 25 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 90,167 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 11 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 71 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 5.00 5.00 10.00 10.00 15.00 15.00 20.00 20.00 25.00 25.00 30.00 30.00 35.00 35.00 Q (cfs) Time (hrs) Flow to WQv#2 Hyd. No. 10 -- 25 Year Hyd No. 10 -- Pond outlet Hyd No. 9 -- Inflow Hyd No. 11 -- 9 minus 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 11 High flow to Array Hydrograph type = Diversion2 Peak discharge = 18.12 cfs Storm frequency = 25 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 24,853 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 10 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 72 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 5.00 5.00 10.00 10.00 15.00 15.00 20.00 20.00 25.00 25.00 30.00 30.00 35.00 35.00 Q (cfs) Time (hrs) High flow to Array Hyd. No. 11 -- 25 Year Hyd No. 11 -- Qin - Pond outlet Hyd No. 9 -- Inflow Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 12 Flow to Array #1 Hydrograph type = Combine Peak discharge = 31.33 cfs Storm frequency = 25 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 115,020 cuft Inflow hyds. = 10, 11 Contrib. drain. area = 0.000 ac 73 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 5.00 5.00 10.00 10.00 15.00 15.00 20.00 20.00 25.00 25.00 30.00 30.00 35.00 35.00 Q (cfs) Time (hrs) Flow to Array #1 Hyd. No. 12 -- 25 Year Hyd No. 12 Hyd No. 10 Hyd No. 11 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 13 Route Array #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 25 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 12 - Flow to Array #1 Max. Elevation = 319.06 ft Reservoir name = Infiltration Array #1 Max. Storage = 171 cuft Storage Indication method used. Exfiltration extracted from Outflow. 74 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 5.00 5.00 10.00 10.00 15.00 15.00 20.00 20.00 25.00 25.00 30.00 30.00 35.00 35.00 Q (cfs) Time (hrs) Route Array #1 Hyd. No. 13 -- 25 Year Hyd No. 13 Hyd No. 12 Total storage used = 171 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 14 Route Basin #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 25 yrs Time to peak = 11.77 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 8 - Post Area #3A Max. Elevation = 320.51 ft Reservoir name = Basin #1 Max. Storage = 2,456 cuft Storage Indication method used. Exfiltration extracted from Outflow. 75 0.0 2.0 4.0 6.0 8.0 10.0 12.0 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 14.00 14.00 Q (cfs) Time (hrs) Route Basin #1 Hyd. No. 14 -- 25 Year Hyd No. 14 Hyd No. 8 Total storage used = 2,456 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 15 Route Wet Swale #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 25 yrs Time to peak = 12.40 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 5 - Post Area #1A Max. Elevation = 320.91 ft Reservoir name = Wet Swale #1 Max. Storage = 1,427 cuft Storage Indication method used. Exfiltration extracted from Outflow. 76 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 Q (cfs) Time (hrs) Route Wet Swale #1 Hyd. No. 15 -- 25 Year Hyd No. 15 Hyd No. 5 Total storage used = 1,427 cuft Hydrograph Summary Report 77 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 0.007 2 1440 144 ------ ------ ------ Pre Area #1 2 SCS Runoff 0.044 2 1440 1,193 ------ ------ ------ Pre Area #2 3 SCS Runoff 0.115 2 828 3,839 ------ ------ ------ Pre Area #3 4 SCS Runoff 0.006 2 1440 151 ------ ------ ------ Post Area #1 5 SCS Runoff 3.200 2 716 6,465 ------ ------ ------ Post Area #1A 6 SCS Runoff 39.65 2 728 145,462 ------ ------ ------ Post Area #2 7 SCS Runoff 0.120 2 758 2,468 ------ ------ ------ Post Area #3 8 SCS Runoff 16.64 2 716 33,652 ------ ------ ------ Post Area #3A 9 Reservoir 39.65 2 728 145,462 6 323.02 14.1 Route STMH#7 10 Diversion1 14.17 2 728 108,467 9 ------ ------ Flow to WQv#2 11 Diversion2 25.48 2 728 36,995 9 ------ ------ High flow to Array 12 Combine 39.65 2 728 145,462 10, 11 ------ ------ Flow to Array #1 13 Reservoir 0.000 2 722 0 12 319.07 2,065 Route Array #1 14 Reservoir 0.000 2 696 0 8 321.03 3,611 Route Basin #1 15 Reservoir 0.000 2 714 0 5 321.12 1,909 Route Wet Swale #1 Saratoga Station (7-11-24).gpw Return Period: 50 Year Monday, 07 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 1 Pre Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.007 cfs Storm frequency = 50 yrs Time to peak = 24.00 hrs Time interval = 2 min Hyd. volume = 144 cuft Drainage area = 2.415 ac Curve number = 30 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 29.30 min Total precip. = 5.30 in Distribution = Type II Storm duration = 24 hrs Shape factor = 600 78 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #1 Hyd. No. 1 -- 50 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 2 Pre Area #2 Hydrograph type = SCS Runoff Peak discharge = 0.044 cfs Storm frequency = 50 yrs Time to peak = 24.00 hrs Time interval = 2 min Hyd. volume = 1,193 cuft Drainage area = 10.554 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 49.40 min Total precip. = 5.30 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 79 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #2 Hyd. No. 2 -- 50 Year Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 3 Pre Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.115 cfs Storm frequency = 50 yrs Time to peak = 13.80 hrs Time interval = 2 min Hyd. volume = 3,839 cuft Drainage area = 8.479 ac Curve number = 35 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 5.30 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 80 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (hrs) Pre Area #3 Hyd. No. 3 -- 50 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 4 Post Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.006 cfs Storm frequency = 50 yrs Time to peak = 24.00 hrs Time interval = 2 min Hyd. volume = 151 cuft Drainage area = 1.337 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 28.60 min Total precip. = 5.30 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 81 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Post Area #1 Hyd. No. 4 -- 50 Year Hyd No. 4 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 5 Post Area #1A Hydrograph type = SCS Runoff Peak discharge = 3.200 cfs Storm frequency = 50 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 6,465 cuft Drainage area = 0.705 ac Curve number = 75 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 5.30 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 82 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 Q (cfs) Time (hrs) Post Area #1A Hyd. No. 5 -- 50 Year Hyd No. 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 6 Post Area #2 Hydrograph type = SCS Runoff Peak discharge = 39.65 cfs Storm frequency = 50 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 145,462 cuft Drainage area = 12.898 ac Curve number = 80 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 24.40 min Total precip. = 5.30 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 83 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 Q (cfs) Time (hrs) Post Area #2 Hyd. No. 6 -- 50 Year Hyd No. 6 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 7 Post Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.120 cfs Storm frequency = 50 yrs Time to peak = 12.63 hrs Time interval = 2 min Hyd. volume = 2,468 cuft Drainage area = 3.008 ac Curve number = 38 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 5.30 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 84 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (hrs) Post Area #3 Hyd. No. 7 -- 50 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 8 Post Area #3A Hydrograph type = SCS Runoff Peak discharge = 16.64 cfs Storm frequency = 50 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 33,652 cuft Drainage area = 3.551 ac Curve number = 76 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 5.30 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 85 0 2 4 6 8 10 12 14 16 18 20 22 24 Q (cfs) 0.00 0.00 3.00 3.00 6.00 6.00 9.00 9.00 12.00 12.00 15.00 15.00 18.00 18.00 Q (cfs) Time (hrs) Post Area #3A Hyd. No. 8 -- 50 Year Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 9 Route STMH#7 Hydrograph type = Reservoir Peak discharge = 39.65 cfs Storm frequency = 50 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 145,462 cuft Inflow hyd. No. = 6 - Post Area #2 Max. Elevation = 323.02 ft Reservoir name = STMH#7 Max. Storage = 14 cuft Storage Indication method used. 86 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 Q (cfs) Time (hrs) Route STMH#7 Hyd. No. 9 -- 50 Year Hyd No. 9 Hyd No. 6 Total storage used = 14 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 10 Flow to WQv#2 Hydrograph type = Diversion1 Peak discharge = 14.17 cfs Storm frequency = 50 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 108,467 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 11 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 87 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 Q (cfs) Time (hrs) Flow to WQv#2 Hyd. No. 10 -- 50 Year Hyd No. 10 -- Pond outlet Hyd No. 9 -- Inflow Hyd No. 11 -- 9 minus 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 11 High flow to Array Hydrograph type = Diversion2 Peak discharge = 25.48 cfs Storm frequency = 50 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 36,995 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 10 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 88 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 Q (cfs) Time (hrs) High flow to Array Hyd. No. 11 -- 50 Year Hyd No. 11 -- Qin - Pond outlet Hyd No. 9 -- Inflow Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 12 Flow to Array #1 Hydrograph type = Combine Peak discharge = 39.65 cfs Storm frequency = 50 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 145,462 cuft Inflow hyds. = 10, 11 Contrib. drain. area = 0.000 ac 89 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 Q (cfs) Time (hrs) Flow to Array #1 Hyd. No. 12 -- 50 Year Hyd No. 12 Hyd No. 10 Hyd No. 11 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 13 Route Array #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 50 yrs Time to peak = 12.03 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 12 - Flow to Array #1 Max. Elevation = 319.07 ft Reservoir name = Infiltration Array #1 Max. Storage = 2,065 cuft Storage Indication method used. Exfiltration extracted from Outflow. 90 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 Q (cfs) Time (hrs) Route Array #1 Hyd. No. 13 -- 50 Year Hyd No. 13 Hyd No. 12 Total storage used = 2,065 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 14 Route Basin #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 50 yrs Time to peak = 11.60 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 8 - Post Area #3A Max. Elevation = 321.03 ft Reservoir name = Basin #1 Max. Storage = 3,611 cuft Storage Indication method used. Exfiltration extracted from Outflow. 91 0.0 2.0 4.0 6.0 8.0 10.0 12.0 Q (cfs) 0.00 0.00 3.00 3.00 6.00 6.00 9.00 9.00 12.00 12.00 15.00 15.00 18.00 18.00 Q (cfs) Time (hrs) Route Basin #1 Hyd. No. 14 -- 50 Year Hyd No. 14 Hyd No. 8 Total storage used = 3,611 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 15 Route Wet Swale #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 50 yrs Time to peak = 11.90 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 5 - Post Area #1A Max. Elevation = 321.12 ft Reservoir name = Wet Swale #1 Max. Storage = 1,909 cuft Storage Indication method used. Exfiltration extracted from Outflow. 92 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 Q (cfs) Time (hrs) Route Wet Swale #1 Hyd. No. 15 -- 50 Year Hyd No. 15 Hyd No. 5 Total storage used = 1,909 cuft Hydrograph Summary Report 93 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 0.023 2 934 803 ------ ------ ------ Pre Area #1 2 SCS Runoff 0.139 2 928 4,824 ------ ------ ------ Pre Area #2 3 SCS Runoff 0.485 2 756 8,947 ------ ------ ------ Pre Area #3 4 SCS Runoff 0.018 2 912 611 ------ ------ ------ Post Area #1 5 SCS Runoff 4.074 2 716 8,264 ------ ------ ------ Post Area #1A 6 SCS Runoff 49.56 2 728 182,192 ------ ------ ------ Post Area #2 7 SCS Runoff 0.421 2 744 4,857 ------ ------ ------ Post Area #3 8 SCS Runoff 21.08 2 716 42,835 ------ ------ ------ Post Area #3A 9 Reservoir 49.56 2 728 182,192 6 323.51 16.0 Route STMH#7 10 Diversion1 15.36 2 728 129,680 9 ------ ------ Flow to WQv#2 11 Diversion2 34.20 2 728 52,513 9 ------ ------ High flow to Array 12 Combine 49.56 2 728 182,192 10, 11 ------ ------ Flow to Array #1 13 Reservoir 0.000 2 712 0 12 319.07 10,634 Route Array #1 14 Reservoir 0.000 2 700 0 8 321.52 5,145 Route Basin #1 15 Reservoir 0.000 2 824 0 5 321.36 2,562 Route Wet Swale #1 Saratoga Station (7-11-24).gpw Return Period: 100 Year Monday, 07 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 1 Pre Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.023 cfs Storm frequency = 100 yrs Time to peak = 15.57 hrs Time interval = 2 min Hyd. volume = 803 cuft Drainage area = 2.415 ac Curve number = 30 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 29.30 min Total precip. = 6.19 in Distribution = Type II Storm duration = 24 hrs Shape factor = 600 94 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Pre Area #1 Hyd. No. 1 -- 100 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 2 Pre Area #2 Hydrograph type = SCS Runoff Peak discharge = 0.139 cfs Storm frequency = 100 yrs Time to peak = 15.47 hrs Time interval = 2 min Hyd. volume = 4,824 cuft Drainage area = 10.554 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 49.40 min Total precip. = 6.19 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 95 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (hrs) Pre Area #2 Hyd. No. 2 -- 100 Year Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 3 Pre Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.485 cfs Storm frequency = 100 yrs Time to peak = 12.60 hrs Time interval = 2 min Hyd. volume = 8,947 cuft Drainage area = 8.479 ac Curve number = 35 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 6.19 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 96 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (hrs) Pre Area #3 Hyd. No. 3 -- 100 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 4 Post Area #1 Hydrograph type = SCS Runoff Peak discharge = 0.018 cfs Storm frequency = 100 yrs Time to peak = 15.20 hrs Time interval = 2 min Hyd. volume = 611 cuft Drainage area = 1.337 ac Curve number = 31 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 28.60 min Total precip. = 6.19 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 97 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (hrs) Post Area #1 Hyd. No. 4 -- 100 Year Hyd No. 4 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 5 Post Area #1A Hydrograph type = SCS Runoff Peak discharge = 4.074 cfs Storm frequency = 100 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 8,264 cuft Drainage area = 0.705 ac Curve number = 75 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 6.19 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 98 0 2 4 6 8 10 12 14 16 18 20 22 24 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 5.00 5.00 Q (cfs) Time (hrs) Post Area #1A Hyd. No. 5 -- 100 Year Hyd No. 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 6 Post Area #2 Hydrograph type = SCS Runoff Peak discharge = 49.56 cfs Storm frequency = 100 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 182,192 cuft Drainage area = 12.898 ac Curve number = 80 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 24.40 min Total precip. = 6.19 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 99 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 50.00 50.00 Q (cfs) Time (hrs) Post Area #2 Hyd. No. 6 -- 100 Year Hyd No. 6 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 7 Post Area #3 Hydrograph type = SCS Runoff Peak discharge = 0.421 cfs Storm frequency = 100 yrs Time to peak = 12.40 hrs Time interval = 2 min Hyd. volume = 4,857 cuft Drainage area = 3.008 ac Curve number = 38 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 30.20 min Total precip. = 6.19 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 100 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (hrs) Post Area #3 Hyd. No. 7 -- 100 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 8 Post Area #3A Hydrograph type = SCS Runoff Peak discharge = 21.08 cfs Storm frequency = 100 yrs Time to peak = 11.93 hrs Time interval = 2 min Hyd. volume = 42,835 cuft Drainage area = 3.551 ac Curve number = 76 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 6.19 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 101 0 2 4 6 8 10 12 14 16 18 20 22 24 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 Q (cfs) Time (hrs) Post Area #3A Hyd. No. 8 -- 100 Year Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 9 Route STMH#7 Hydrograph type = Reservoir Peak discharge = 49.56 cfs Storm frequency = 100 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 182,192 cuft Inflow hyd. No. = 6 - Post Area #2 Max. Elevation = 323.51 ft Reservoir name = STMH#7 Max. Storage = 16 cuft Storage Indication method used. 102 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 50.00 50.00 Q (cfs) Time (hrs) Route STMH#7 Hyd. No. 9 -- 100 Year Hyd No. 9 Hyd No. 6 Total storage used = 16 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 10 Flow to WQv#2 Hydrograph type = Diversion1 Peak discharge = 15.36 cfs Storm frequency = 100 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 129,680 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 11 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 103 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 50.00 50.00 Q (cfs) Time (hrs) Flow to WQv#2 Hyd. No. 10 -- 100 Year Hyd No. 10 -- Pond outlet Hyd No. 9 -- Inflow Hyd No. 11 -- 9 minus 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 11 High flow to Array Hydrograph type = Diversion2 Peak discharge = 34.20 cfs Storm frequency = 100 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 52,513 cuft Inflow hydrograph = 9 - Route STMH#7 2nd diverted hyd. = 10 Diversion method = Pond - STMH#7 Pond structure = Culv/Orf A 104 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 50.00 50.00 Q (cfs) Time (hrs) High flow to Array Hyd. No. 11 -- 100 Year Hyd No. 11 -- Qin - Pond outlet Hyd No. 9 -- Inflow Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 12 Flow to Array #1 Hydrograph type = Combine Peak discharge = 49.56 cfs Storm frequency = 100 yrs Time to peak = 12.13 hrs Time interval = 2 min Hyd. volume = 182,192 cuft Inflow hyds. = 10, 11 Contrib. drain. area = 0.000 ac 105 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 50.00 50.00 Q (cfs) Time (hrs) Flow to Array #1 Hyd. No. 12 -- 100 Year Hyd No. 12 Hyd No. 10 Hyd No. 11 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 13 Route Array #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 100 yrs Time to peak = 11.87 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 12 - Flow to Array #1 Max. Elevation = 319.07 ft Reservoir name = Infiltration Array #1 Max. Storage = 10,634 cuft Storage Indication method used. Exfiltration extracted from Outflow. 106 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 50.00 50.00 Q (cfs) Time (hrs) Route Array #1 Hyd. No. 13 -- 100 Year Hyd No. 13 Hyd No. 12 Total storage used = 10,634 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 14 Route Basin #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 100 yrs Time to peak = 11.67 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 8 - Post Area #3A Max. Elevation = 321.52 ft Reservoir name = Basin #1 Max. Storage = 5,145 cuft Storage Indication method used. Exfiltration extracted from Outflow. 107 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 Q (cfs) Time (hrs) Route Basin #1 Hyd. No. 14 -- 100 Year Hyd No. 14 Hyd No. 8 Total storage used = 5,145 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Hyd. No. 15 Route Wet Swale #1 Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 100 yrs Time to peak = 13.73 hrs Time interval = 2 min Hyd. volume = 0 cuft Inflow hyd. No. = 5 - Post Area #1A Max. Elevation = 321.36 ft Reservoir name = Wet Swale #1 Max. Storage = 2,562 cuft Storage Indication method used. Exfiltration extracted from Outflow. 108 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 5.00 5.00 Q (cfs) Time (hrs) Route Wet Swale #1 Hyd. No. 15 -- 100 Year Hyd No. 15 Hyd No. 5 Total storage used = 2,562 cuft Hydraflow Rainfall Report 109 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2021 Monday, 07 / 15 / 2024 Return Intensity-Duration-Frequency Equation Coefficients (FHA) Period (Yrs) B D E (N/A) 1 0.0000 0.0000 0.0000 -------- 2 69.8703 13.1000 0.8658 -------- 3 0.0000 0.0000 0.0000 -------- 5 79.2597 14.6000 0.8369 -------- 10 88.2351 15.5000 0.8279 -------- 25 102.6072 16.5000 0.8217 -------- 50 114.8193 17.2000 0.8199 -------- 100 127.1596 17.8000 0.8186 -------- File name: SampleFHA.idf Intensity = B / (Tc + D)^E Return Intensity Values (in/hr) Period (Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2 5.69 4.61 3.89 3.38 2.99 2.69 2.44 2.24 2.07 1.93 1.81 1.70 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5 6.57 5.43 4.65 4.08 3.65 3.30 3.02 2.79 2.59 2.42 2.27 2.15 10 7.24 6.04 5.21 4.59 4.12 3.74 3.43 3.17 2.95 2.77 2.60 2.46 25 8.25 6.95 6.03 5.34 4.80 4.38 4.02 3.73 3.48 3.26 3.07 2.91 50 9.04 7.65 6.66 5.92 5.34 4.87 4.49 4.16 3.88 3.65 3.44 3.25 100 9.83 8.36 7.30 6.50 5.87 5.36 4.94 4.59 4.29 4.03 3.80 3.60 Tc = time in minutes. Values may exceed 60. Rainfall Precipitation Table (in) Precip. file name: I:\Engineering Projects\Prime Companies\2022\2022-02-Saratoga Station\03-Admin\Reports\Storm Report\Exhibit C-Hydrographs\saratoga.pcp Storm Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr SCS 24-hour 2.23 2.61 0.00 1.20 3.71 4.54 5.30 6.19 SCS 6-Hr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-1st 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Custom 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Stormwater Management Report July 2024 Page 20 Exhibit D – Drainage Calculations .1 Pipe Capacities and Expected Flows PROJECT #SHEET #OF:PAGE #OF: MADE BY: DATE: PROJECT:CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: CB#63 CB#64 CB#65 CB#66 FI#11 Expected flow calculations in Pipe Runs Q=Drainage area to CB x 10 year peak dischargeTotal Area of Watershed (Post Development Area #1A) CB#62 2653 1.71% 0.16 CB#61 0.36% CB#60 1062 0.69% 0.06 CB#59 2506 1.62% 0.15 CB#58 839 0.54% 0.05 CB#57 8969 5.80% 0.53 CB#56 11845 7.66% 0.70 CB#55 5348 3.46% 0.32 CB#54 10878 7.03% 0.64 CB#53 4038 2.61% 0.24 CB#52 7576 4.90% 0.45 CB#51 2432 1.57% 0.14 FES #10 11544 7.46% 0.68 0.80 CB#49 10680 6.90% 0.63 CB#48 21305 13.77% 1.26 POST DEVELOPMENT AREA #1A CB#2 10385 33.80% 0.59 Drainage Structure Drainage Area (sf) To CB Percentage of Watershed Expected 10-year Peak Flow (cfs) to CB/FI Flow to Catch Basins POST DEVELOPMENT AREA #3A 2022-02 1 1 JWE 5/15/2024 Station Park CB#1 16240 52.86% 0.92 CB#50 13523 8.74% 1526 0.99% 0.09 550 12050 7.79% 0.71 3788 2.45% 0.22 2156 86.66% 1.51 0.03 2481 1.60% 0.15 1.39% 0.13 Total Area=137749 89.04% 8.16 Total Area=26625 7/15/2024 Pipes mann2.xls Post #1a and #3A PROJECT #SHEET #OF:PAGE #OF: MADE BY: DATE: PROJECT:CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: CB#24 CB#25 CB#26 CB#27 CB#28 CB#29 CB#30 CB#31 CB#32 CB#33 CB#34 CB#35 CB#36 CB#37 CB#38 FES#4 Expected flow calculations in Pipe Runs Q= 2022-02 1 1 JWE 5/15/2024 Station Park Flow to Catch Basins Drainage Structure Drainage Area (sf) To CB Percentage of Watershed Expected 10- year Peak Flow (cfs) to CB/FI/CO Expected 10-year Peak Flow (cfs) to CB/FI/CO Drainage Structure 23468 4.18% 0.95 CB#4 14170 2.52% 0.58 0.61 CB#5 6513 1.16% 0.26 0.30CB#41 7283 1.30% CB#8 0.4410940 1.95% CB#10 9544 1.70% 0.39 CB#9 22352 3.98% 0.91 0.22 CB#11 3592 0.64% 0.15 0.82CB#47 20118 CB#12 15300 2.72% 0.62 0.45 0.45 CB#14 2756 0.49% 0.11 CB#13 5581 0.99% 0.23 0.07 CB#15 5941 1.06% 0.24 0.45CO#3 11000 CB#16 4747 0.84% 0.19 0.45 0.45 CB#18 1370 0.24% 0.06 CB#17 1054 0.19% 0.04 0.45 CB#19 1501 0.27% 0.06 0.01 FI#3 11000 CB#20 4703 0.84% 0.19 0.45 0.45 CB#22 10425 1.86% 0.42 CB#21 6584 1.17% 0.27 0.45 CB#23 5085 0.91% 0.21 0.45CO#19 11000 7617 1.36% 0.31 10130 1.80% 0.41 13417 2.39% 0.54 8973 1.60% 0.36 Total Area=325532 11581 59231 10.54% 2.40 6698 1.19% 0.27 Drainage area to CB x 10 year peak dischargeTotal Area of Watershed (Post Development Area #2) CB#6 1202 0.21% 0.05 9025 1.61% 0.37 CB#44 0.13 CB#7 1930 0.34% 0.08 2.11 CB#42 3241 2.44% 2.06% 0.47 20063 3.57% 0.81 0.5613683 2908 0.52% 0.12 3827 0.68% 0.16 5450 0.97% 0.22 5111 0.91% 0.21 Drainage Area (sf) To CB Percentage of Watershed CB#39 CB#40 15150 2.70% POST DEVELOPMENT AREA #2 CB#3 0.58% CB#43 52054 9.26% CB#46 5327 0.95% 3.58% CB#45 CO#1 11000 1.96% CO#2 11000 1.96% FI#1 1762 0.31% 1.96% CO#4 11000 1.96% CO#6 11000 1.96% 1.96% FI#5 300 0.05% CO#13 11000 1.96% CO#14 11000 1.96% CO#18 11000 1.96% 1.96% 11000 1.96% 0.45 FI#6 237175Sub Total= Total Area=562707 100.2% 7/15/2024 Pipes mann2.xls Post #2 Stormwater Management Report July 2024 Page 21 Exhibit E – Maps .1 Project Location Map .2 Soil Map (Figure 1) .3 Pre-Development Watersheds (Figure 2) .4 Post Development Watersheds (Figure 3) .5 Catch Basin Sub-Watershed Areas (Figure 4) STATION LANE NYS ROUTE 29X WnCHYDROLOGICGROUP"A"WnBHYDROLOGICGROUP"A"SaHYDROLOGICGROUP"A"DeAHYDROLOGICGROUP"A"WaHYDROLOGICGROUP"A"THE ALTERATION OF THIS MATERIAL INANY WAY, UNLESS DONE UNDER THEDIRECTION OF A COMPARABLEPROFESSIONAL, (I.E.) ARCHITECT FORAN ARCHITECT, ENGINEER FOR ANENGINEER OR LANDSCAPE ARCHITECTFOR A LANDSCAPE ARCHITECT, IS AVIOLATION OF THE NEW YORK STATEEDUCATION LAW AND/OR REGULATIONSAND IS A CLASS "A" MISDEMEANOR.SEALDATENo.DESCRIPTIONSUBMITTAL / REVISIONSPROJ. MANAGER:CHIEF DESIGNER:BYDESIGNED BY:DRAWN BY:DATE:PROJ. No.:SCALE:File Name: I:\Engineering Projects\Prime Companies\2022\2022-02-Saratoga Station\04-Cad File\Stormwater.dwg (Layout: SOIL )Date: Mon, Jul 15, 2024 - 11:37 AM (Name: JamieEaston)1"=120'2022-02JULY 2024CITY OF SARATOGA SPRINGSNEW YORKSOILS MAPFig-1JWEJWEJWEJWEEP LAND SERVICES LLC621 COLUMBIA STREET- COHOES, NY 12047PHONE: 518-785-9000060'120'120'TAX PARCELS 165-2-70, 165-2-18, & 165-2-19NYS ROUTE 29 (WASHINGTON AVE)PRIME COMPANIES- STATION PARK STATION LANE NYS ROUTE 29X 150' SHEETFLOW119' SCF102' CHANNELFLOW150' SHEETFLOW452' SCF150' SHEETFLOW455' SCFSEALDATENo.DESCRIPTIONSUBMITTAL / REVISIONSPROJ. MANAGER:CHIEF DESIGNER:BYDESIGNED BY:DRAWN BY:DATE:PROJ. No.:SCALE:File Name: I:\Engineering Projects\Prime Companies\2022\2022-02-Saratoga Station\04-Cad File\Stormwater.dwg (Layout: PRE )Date: Mon, Jul 15, 2024 - 11:38 AM (Name: JamieEaston)1"=120'2022-02JULY 2024CITY OF SARATOGA SPRINGSNEW YORKPRE-DEVELOPMENT WATERSHEDSFig-2JWEJWEJWEJWEEP LAND SERVICES LLC621 COLUMBIA STREET- COHOES, NY 12047PHONE: 518-785-9000060'120'120'TAX PARCELS 165-2-70, 165-2-18, & 165-2-19NYS ROUTE 29 (WASHINGTON AVE)PRIME COMPANIES- STATION PARKTHE ALTERATION OF THIS MATERIAL INANY WAY, UNLESS DONE UNDER THEDIRECTION OF A COMPARABLEPROFESSIONAL, (I.E.) ARCHITECT FORAN ARCHITECT, ENGINEER FOR ANENGINEER OR LANDSCAPE ARCHITECTFOR A LANDSCAPE ARCHITECT, IS AVIOLATION OF THE NEW YORK STATEEDUCATION LAW AND/OR REGULATIONSAND IS A CLASS "A" MISDEMEANOR.DISCHARGEPOINT #1DISCHARGEPOINT #2DISCHARGEPOINT #3PRE DEVELOPMENTAREA #1PRE DEVELOPMENTAREA #3PRE DEVELOPMENTAREA #2 STATION LANE NYS ROUTE 29X ■■ST STST ■■HOTEL4 STORIES110 ROOMSWITH 17 COVERED PARKING STALLSROW HOUSE #7ROW HOUSE #8ROW HOUSE #9ROW HOUSE #10ROW HOUSE #11ROW HOUSE #12ROW HOUSE #13ROW HOUSE #14ROW HOUSE #15ROW HOUSE #16 ROW HOUSE #17 ROW HOUSE #18 ROW HOUSE #41 ROW HOUSE #42 ROW HOUSE #43 ROW HOUSE #44 ROW HOUSE #45 ROW HOUSE #46 ROW HOUSE #35 ROW HOUSE #36 ROW HOUSE #37 ROW HOUSE #38 ROW HOUSE #39 ROW HOUSE #40 ROW HOUSE #31 ROW HOUSE #32 ROW HOUSE #33 ROW HOUSE #34 STSTSTSTSTSTROW HOUSE #1ROW HOUSE #2ROW HOUSE #3ROW HOUSE #4ROW HOUSE #5ROW HOUSE #6 ROW HOUSE #19 ROW HOUSE #20 ROW HOUSE #21 ROW HOUSE #22 ROW HOUSE #23 ROW HOUSE #24BLDG #1MULTIFAMILY4 STORIES184 UNITS162 UNDERGROUND PARKING STALLSBLDG #2MULTIFAMILY4 STORIES160 UNITS165 UNDERGROUND PARKING STALLS2 STORY MAINTENANCE BLDG.100'x20'STATION PARK AVESTATION PARK AVERAILROAD AVE (PRIVATE ROAD)■■■■STSTSTSTSTSTSTSTSTSTST ■■■■■■■■■■MAINT.BLDG./COVEREDPATIO67'x32'ST ■■■■■■■■ ■■■ROW HOUSE #25 ROW HOUSE #26 ROW HOUSE #27 ROW HOUSE #28 ROW HOUSE #29 ROW HOUSE #30■■■STSTSTSTSTSTSTSTSTSTST STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTST■■■■■■■■■■■■■150' SHEETFLOW102' CHANNELFLOW30' SCF266' SCF100' SHEETFLOW150' SHEETFLOW400' CHANNELFLOW255' SCFSEALDATENo.DESCRIPTIONSUBMITTAL / REVISIONSPROJ. MANAGER:CHIEF DESIGNER:BYDESIGNED BY:DRAWN BY:DATE:PROJ. No.:SCALE:File Name: I:\Engineering Projects\Prime Companies\2022\2022-02-Saratoga Station\04-Cad File\Stormwater.dwg (Layout: POST )Date: Mon, Jul 15, 2024 - 11:48 AM (Name: JamieEaston)1"=120'2022-02JULY 2024CITY OF SARATOGA SPRINGSNEW YORKPOST DEVELOPMENT WATERSHEDSFig-3JWEJWEJWEJWEEP LAND SERVICES LLC621 COLUMBIA STREET- COHOES, NY 12047PHONE: 518-785-9000060'120'120'TAX PARCELS 165-2-70, 165-2-18, & 165-2-19NYS ROUTE 29 (WASHINGTON AVE)PRIME COMPANIES- STATION PARKTHE ALTERATION OF THIS MATERIAL INANY WAY, UNLESS DONE UNDER THEDIRECTION OF A COMPARABLEPROFESSIONAL, (I.E.) ARCHITECT FORAN ARCHITECT, ENGINEER FOR ANENGINEER OR LANDSCAPE ARCHITECTFOR A LANDSCAPE ARCHITECT, IS AVIOLATION OF THE NEW YORK STATEEDUCATION LAW AND/OR REGULATIONSAND IS A CLASS "A" MISDEMEANOR.DISCHARGEPOINT #1DISCHARGEPOINT #3POSTDEVELOPMENTAREA #1APOSTDEVELOPMENTAREA #3POST DEVELOPMENTAREA #2POSTDEVELOPMENTAREA #3APOST DEVELOPMENTAREA #1A STATION LANE NYS ROUTE 29X ■■ST STST ■■HOTEL4 STORIES110 ROOMSWITH 17 COVERED PARKING STALLSROW HOUSE #7ROW HOUSE #8ROW HOUSE #9ROW HOUSE #10ROW HOUSE #11ROW HOUSE #12ROW HOUSE #13ROW HOUSE #14ROW HOUSE #15ROW HOUSE #16 ROW HOUSE #17 ROW HOUSE #18 ROW HOUSE #41 ROW HOUSE #42 ROW HOUSE #43 ROW HOUSE #44 ROW HOUSE #45 ROW HOUSE #46 ROW HOUSE #35 ROW HOUSE #36 ROW HOUSE #37 ROW HOUSE #38 ROW HOUSE #39 ROW HOUSE #40 ROW HOUSE #31 ROW HOUSE #32 ROW HOUSE #33 ROW HOUSE #34 STSTSTSTSTSTROW HOUSE #1ROW HOUSE #2ROW HOUSE #3ROW HOUSE #4ROW HOUSE #5ROW HOUSE #6 ROW HOUSE #19 ROW HOUSE #20 ROW HOUSE #21 ROW HOUSE #22 ROW HOUSE #23 ROW HOUSE #24BLDG #1MULTIFAMILY4 STORIES184 UNITS162 UNDERGROUND PARKING STALLSBLDG #2MULTIFAMILY4 STORIES160 UNITS165 UNDERGROUND PARKING STALLS2 STORY MAINTENANCE BLDG.100'x20'STATION PARK AVESTATION PARK AVERAILROAD AVE (PRIVATE ROAD)■■■■STSTSTSTSTSTSTSTSTSTST ■■■■■■■■■■MAINT.BLDG./COVEREDPATIO67'x32'ST ■■■■■■■■ ■■■ROW HOUSE #25 ROW HOUSE #26 ROW HOUSE #27 ROW HOUSE #28 ROW HOUSE #29 ROW HOUSE #30■■■STSTSTSTSTSTSTSTSTSTST STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTST■■■■■■■■■■■■■SEALDATENo.DESCRIPTIONSUBMITTAL / REVISIONSPROJ. MANAGER:CHIEF DESIGNER:BYDESIGNED BY:DRAWN BY:DATE:PROJ. No.:SCALE:File Name: I:\Engineering Projects\Prime Companies\2022\2022-02-Saratoga Station\04-Cad File\Stormwater.dwg (Layout: cb )Date: Mon, Jul 15, 2024 - 1:11 PM (Name: JamieEaston)1"=120'2022-02JULY 2024CITY OF SARATOGA SPRINGSNEW YORKCATCH BASIN WATERSHED AREASFig-4JWEJWEJWEJWEEP LAND SERVICES LLC621 COLUMBIA STREET- COHOES, NY 12047PHONE: 518-785-9000060'120'120'TAX PARCELS 165-2-70, 165-2-18, & 165-2-19NYS ROUTE 29 (WASHINGTON AVE)PRIME COMPANIES- STATION PARKTHE ALTERATION OF THIS MATERIAL INANY WAY, UNLESS DONE UNDER THEDIRECTION OF A COMPARABLEPROFESSIONAL, (I.E.) ARCHITECT FORAN ARCHITECT, ENGINEER FOR ANENGINEER OR LANDSCAPE ARCHITECTFOR A LANDSCAPE ARCHITECT, IS AVIOLATION OF THE NEW YORK STATEEDUCATION LAW AND/OR REGULATIONSAND IS A CLASS "A" MISDEMEANOR.CB#2CB#1CB#12CB#10CB#11CB#13CB#15CB#14CB#31CB#30CB#32CB#33CB#35CB#34CB#38CB#36CB#40CB#41CB#42CB#43CB#44CB#26CB#25CB#29CB#27CB#28CB#9CB#21CB#20CB#24CB#23CB#57CB#56CB#55CB#54CB#50CB#49CB#48CB#47CB#46CB#64CB#65CB#66CB#53CB#52CB#51CB#63CB#62CB#60CB#59CB#58CB#4CB#3CB#5CB#6CB#7CB#14CB#16CB#17CB#18CB#19CB#22FES#10 Prepared by: EP Land Services LLC 621 Columbia Street Ext. Cohoes, NY 12047 (518) 785-9000 Stormwater Pollution Prevention Plan (SWPPP) for (Part II) Station Park Subdivision City of Saratoga Springs Saratoga County, New York July 12, 2024 July 2024 STORMWATER POLLUTION PREVENTION PLAN for STATION PARK SUBDIVISION CITY OF SARATOGA SPRINGS, SARATOGA COUNTY Table of Contents 1.0 OWNER AND CONTRACTOR’S/SUBCONTRACTOR’S CERTIFICATION ............................... 1 1.1 NOI Permittee’s Certification: .............................................................................................................. 1 1.2 General Site Contractor’s Contractor and Subcontractors Certification: ....................................... 1 1.3 Building Contractor and Subcontractors Certification: .................................................................... 4 2.0 NYSDEC GUIDELINES FOR PREPARING A SWPPP .............................................................. 6 2.1 Stormwater Pollution Prevention (SWPPP) Requirements ............................................................... 6 A. The Narrative Report .......................................................................................................................... 6 B. Maps ................................................................................................................................................... 7 C. Plan Components ............................................................................................................................... 8 2.2 Erosion and Sediment Control Design Elements By NYSDEC ........................................................ 8 2.3 SWPPP Requirements For Water Quality and Water Quantity Control Plans .............................. 12 A. Mapping requirements: ..................................................................................................................... 12 B. Hydrologic and hydraulic analysis: ................................................................................................... 13 C. Finalize landscaping ......................................................................................................................... 14 D. Maintenance Plan ............................................................................................................................. 14 2.4 Construction Sequence Scheduling ................................................................................................. 15 3.0 CONSTRUCTION EROSION CONTROL PRACTICES ............................................................ 16 4.0 CONSTRUCTION WASTE MANAGEMENT............................................................................. 17 5.0 SEQUENCE OF CONSTRUCTION .......................................................................................... 18 6.0 EROSION CONTROL MAINTENANCE DURING CONSTRUCTION ....................................... 19 7.0 GENERAL PERMIT (GP-0-20-002) INFORMATION ................................................................ 20 7.1 Historical Places ................................................................................................................................. 20 7.2 Endangered Species ........................................................................................................................... 20 7.3 Notice of Intent .................................................................................................................................... 20 7.4 Notice of Termination ......................................................................................................................... 20 Exhibits ............................................................................................................................................................. 21 Exhibit F – Stormwater Pollution Prevention Plan (SWPPP) ....................................................................... 22 .1 Notice of Intent (NOI) ........................................................................................................................ 22 .2 MS4 agreement ................................................................................................................................ 22 .3 General Permit .................................................................................................................................. 22 .4 Construction Site Log Book .............................................................................................................. 22 .5 Notice of Termination (NOT) ............................................................................................................. 22 .6 NYSOPRHP and NYSDEC Correspondence ................................................................................... 22 I:\ENGINEERING PROJECTS\PRIME COMPANIES\2022\2022-02-SARATOGA STATION\03-ADMIN\REPORTS\STORM REPORT\EXHIBIT F-SWPPP\SWPPP.DOCX SWPPP July 2024 Page 1 1.0 OWNER AND CONTRACTOR’S/SUBCONTRACTOR’S CERTIFICATION Notice of Intent (NOI) Permitee and General Contractor and Subcontractors shall read Section 2.0 through Section 5.0 of Stormwater Pollution Prevention Plan (SWPPP). Each representative of his or her company shall understand their responsibilities, base upon their scope of work, that Erosion Control and Pollution Control are required for this project. The NOI Permittee, General Contractor and all Subcontractors shall sign the ”logbook” listed below. If a Subcontractor wishes NOT to sign the logbook the General Contractor is to obtain the name, company and phone number of this company and list the information in the logbook. 1.1 NOI Permittee’s Certification: “I hereby certify that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspector during a site inspection. I also understand that the owner or operator must comply with the terms and conditions of the New York State Pollutant Discharge Elimination System (“SPDES”) general permit for stormwater discharge from construction activities and that it is unlawful for any person to cause or contribute to a violation of water quality standards. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of referenced permit and the laws of State of New York and could subject me to criminal, civil and/or administrative proceedings.” Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Company Address:______________________________________________ _____________________________________________________ Phone #:______________________________________________ 1.2 General Site Contractor’s Contractor and Subcontractors Certification: “I hereby certify that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspector during a site inspection. I also understand that the owner or operator must comply with the terms and conditions of the New York State Pollutant Discharge Elimination System (“SPDES”) general permit for stormwater discharge from construction activities and that it is unlawful for any person to cause or contribute to a violation of water quality standards. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of referenced permit and the laws of State of New York and could subject me to criminal, civil and/or administrative proceedings.” General Site Contractor Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Company Address:______________________________________________ _____________________________________________________ Phone #:____________________________________________ SWPPP July 2024 Page 2 Each Subcontractor to site General Contractor (GC) or contractor responsible for site construction aspects shall list their company responsibility (i.e. Landscaper, Underground Utilities (water or sewer) Installer, Electric Service Installer, Gas Service Installer, Asphalt Pavement Installer, Curb (concrete, granite) Installer, Lighting Installer, etc.) SubContractor to Site GC (list responsibility)_________________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ General Site SubContractor (list responsibility)____________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Site GC (list responsibility)_________________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Site GC (list responsibility)_________________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Site GC (list responsibility)_________________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Site GC (list responsibility)_________________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ For each subcontractor listed, the affidavit statement in Section 1.2 of this document shall apply. SWPPP July 2024 Page 3 SubContractor to Site GC (list responsibility)_________________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ General Site SubContractor (list responsibility)____________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Site GC (list responsibility)_________________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Site GC (list responsibility)_________________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Site GC (list responsibility)_________________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Site GC (list responsibility)_________________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ For each subcontractor listed, the affidavit statement in Section 1.2 of this document shall apply. SWPPP July 2024 Page 4 1.3 Building Contractor and Subcontractors Certification: “I hereby certify that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspector during a site inspection. I also understand that the owner or operator must comply with the terms and conditions of the New York State Pollutant Discharge Elimination System (“SPDES”) general permit for stormwater discharge from construction activities and that it is unlawful for any person to cause or contribute to a violation of water quality standards. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of referenced permit and the laws of State of New York and could subject me to criminal, civil and/or administrative proceedings.” Building Contractor Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Company Address:______________________________________________ _____________________________________________________ Phone #:______________________________________________ Each Subcontractor to site General Contractor (GC) of the building(s) or contractor responsible for building construction aspects shall list their company responsibility (i.e. Electrical, Plugging, Masonry, Structural, Foundations, Fit-Up, etc.) SubContractor to Building GC (list Responsibility)_____________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:_______________________________________________ SubContractor to Building GC (list Responsibility)_____________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Building GC (list Responsibility)_____________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:_______________________________________________ SWPPP July 2024 Page 5 SubContractor to Building GC (list Responsibility)_____________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Building GC (list Responsibility)_____________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Building GC (list Responsibility)_____________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:_______________________________________________ SubContractor to Building GC (list Responsibility)_____________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Building GC (list Responsibility)_____________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ SubContractor to Building GC (list Responsibility)_____________________________________________________ Print Name: ______________________________________________ Company Name:________________________________________________ Signature:________________________________________________ Phone #:______________________________________________ For each subcontractor listed, the affidavit statement in Section 1.3 of this document shall apply. SWPPP July 2024 Page 6 2.0 NYSDEC GUIDELINES FOR PREPARING A SWPPP 2.1 Stormwater Pollution Prevention (SWPPP) Requirements A. The Narrative Report Provide applicant information such as name, legal address and phone number on the cover sheet or attach a copy the NOI after submission of the form. (A Draft NOI can be found at and of this Exhibit F.1) 1. Provide address and complete description of the site along with background information about the scope of the project. (See Section 1.0 of Stormwater Management Report (SWMR).) 2. Provide a statement of stormwater management objectives. (See Section 1.0 of SWMR.) 3. Provide a brief description of pre-development conditions: a. Identify the natural drainage areas and drainage points. (See Section 3.0 of SWMR and Exhibit E.3). b. Name the bodies of waters and wetlands and describe the drainage structures on the site of impacted by the site. (See Exhibits E.3 and Construction Drawings) c. Identify critical and environmentally sensitive areas such as high erodible areas, steep slopes, natural resource conservation areas, and wildlife habitats. (See Exhibits E.3 and Construction Drawings) d. Identify utility lines, easements, water supply wells, and sewage treatment systems. (See Exhibits E.3 and Construction Drawings) e. Identify soil type: · General description (texture, permeability, drainage capacity) (See Section 2.0 of SWMR and Exhibits E.2) · Hydrologic Soil Group (HSG) for hydrologic calculations (See Section 2.0 of SWMR and Exhibits E.2) 4. Describe the future site: Provide a brief description of planned post-development conditions, the stormwater runoff quality and quantity comparing to pre-development conditions, and the measures employed to maintain a safe stormwater discharge: (See Section 1.0, 3.0, 4.0 and 5.0 of SWMR and Exhibits E.3 and E.4) Site Address NYS Route 29 Descriptive Site Location Property located between NYS Route 29 and Station Lane Property Owner Prime Companies 621 Columbia Street Ext. Cohoes NY 12047 Property Management (if different than Owner) SAME AS OWNER SWPPP July 2024 Page 7 a. The proposed development and the scope of the SWPPP. (See Section 5.0 of SWMR) b. Disturbed area in acres (16.8 acres) c. Duration of activity, from (10/31/2025~11/1/2030) d. Acreage, location and boundaries of proposed impervious area (See Exhibits E.4, E.5, A.2 and Construction Drawings) e. Future utility lines, easements, water supply wells, and sewage treatment systems. (See Exhibits E.4 and Construction Drawings) f. Define environmentally sensitive areas that will be protected from disturbance (See Exhibits E.4 and Construction Drawings) g. Define the divide lines of drainage areas in the future site according to proposed changes. (See Exhibits E.4 and Construction Drawings) h. The SWPPP should include the following pollution prevention measures: · Identify the plan for preventing litter, construction chemicals, and construction debris exposed to stormwater from becoming a pollutant source in storm water discharges (e.g., screening outfalls, picked up daily; and (See Section 4.0 of this report) · Describe how construction and waste materials will be stored on-site and the controls planned to reduce pollutants from these materials, including storage practices to minimize exposure of the materials to stormwater, and spill prevention and response. (See Section 4.0 of this report) i. If the site discharges to a TMDL or 303d segment, it is the responsibility of the applicant to identify the requirements and accommodate them in the SWPPP. (n/a) j. The responsible person(s) for implementation of the SWPPP and inspection. The plan must identify the contractor(s) and subcontractor(s) responsible for each measure and include and signed contractor certification statement. (See Section 1.0 of this report for contactor and owner certification) k. An updated plan must include copies of the written summaries of the compliance status that are prepared quarterly. The updated plan and required reports must be signed / certified by the permittee. (See Section 6.0 of this report for NYSDEC quarterly form) B. Maps Attach individual maps. 1. Provide, at minimum, a 1:24,000, scale map that identifies: · location of the site · topography · offsite drainage area · bodies of water in the vicinity of the site (See Exhibits E.1 through E.4 and Construction Drawings) 2. Provide a 1”=50’ to 1”=100’ map that shows the existing condition of the site including: · contour lines · drainage area · structures SWPPP July 2024 Page 8 · natural resources and vegetative cover · water bodies, streams perennial and intermittent (See Exhibits E.1 through E.3 and Construction Drawings) 3. Provide individual map(s) based on the requirement of each component of the SWPPP to show all the above features for the future condition of the site: · final grading, areas of cuts and fills and change of land cover · future utility lines, easements, water supply wells, and sewage treatment systems · locations of off-site material, waste, borrow or equipment storage areas · points of stormwater discharge, flow patterns and discharges to surface water · all proposed practices: E&SC, water quality controls · boundaries of existing predominant vegetation and proposed limits of clearing (See Exhibits E.4 and construction drawings) C. Plan Components The three components of a SWPPP are: Erosion and Sediment Control; Water Quality Control and Quantity Control. (See Exhibits E.1 through E.4, construction drawings and Section 5.0 of SWMR demonstrate how the three components of the SWPPP are managed) 2.2 Erosion and Sediment Control Design Elements By NYSDEC A generic E&SC plan may be utilized for minor grading activities associated with small construction activities. Any sites with and approved standard grading plan also require an E&SC plan designed for the site at the same time as the grading plan development. The following describes basic steps in preparing and E&SC plan. A complete set of design specifications and maintenance requirements of all the E&SC practices may be found in the Department’s technical standards for erosion and sedimentation control NY Standards for Erosion and Sediment Control. Follow construction sequence scheduling. The sequence of actions in an E&SC plan is runoff control, stabilization, and then sediment control. The management practices used in each phase of the plan must be identified on the Construction Sequence Schedule and appropriate maps. Erosion and sediment control provisions should be included for all construction activities where any excavation, stripping, filling, grading or earth movement takes place. Provide dimensional details of proposed practices. The details must include plan and vertical view (cross sectional design) calculations used in sizing and justification for the sizing of selected practices. (The following Step 1 through 8 should be incorporated into the plan SWPPP package. Step 1 through 8 were incorporated where applicable and are discussed in Sections 3.0 through 6.0 in further detail and depicted in the Construction Drawings package.) Step 1: Pre-Construction Actions Resource Protection · Evaluate, mark and protect important trees and associated rooting zones, wetlands, on-site septic systems absorption fields, etc. (See Construction Drawings SWPPP Drawing) · Protect existing vegetated areas suitable for filter strips, especially in perimeter areas. (See Construction Drawings) Surface Water Protection SWPPP July 2024 Page 9 · Identify the drainage area in the plan. Divide the site into natural drainage areas. (See Exhibits E.3 and E.4) · Divert the off-site clean runoff from entering disturbed areas. (See Construction Drawings) · Identify bodies of water located on site or in the vicinity of the site. (See Construction Drawings and Exhibits E.3 and E.4) · Plan appropriate practices to protect on-site or downstream surface water. (See Construction Drawings) Stabilize Construction Entrance · Establish a temporary construction entrance to capture mud and debris from construction vehicles before then enter the public highway. (See Construction Drawings) · Stabilize bare areas (entrances, construction routes, equipment parking areas) immediately as work takes place. Top these areas with gravel or maintain vegetative cover. (See Construction Drawings) · Sediment tracked onto public streets should be removed or cleaned on a daily basis. (See Construction Drawings) Perimeter Sediment Controls · Silt fence material and installation comply with the standard drawing and specifications. (See Construction Drawings and Section 3.0) · Install silt fences based on appropriate spacing intervals. Decrease this interval as the slope increases. Silt fence should be placed on or parallel to contours where this is no erosion. The area below the silt fence should be undisturbed ground. (See Construction Drawing SWPPP Drawing) · Install principal basins after construction site is assessed. (See Construction Drawing SWPPP Drawing) · Install additional sediment traps and barriers as needed during grading. (See Construction Drawing SWPPP Drawing) Step2: Runoff and Drainage Control Runoff Control · Install practices after sediment traps are installed and before land grading starts. (See Construction Drawings and Section 3.0) · Control the runoff in each small drainage area before flow reaches runoff from entire site. (See Construction Drawings) · Divert offsite or clean runoff from disturbed areas. (See Construction Drawings ) · Convey surface flows from highly erodible soil and steep slope to more suitable stable area. (See Construction Drawings) · Runoff from existing or proposed cut and fill slopes should be redirected to lower water velocity without causing erosion. (See Construction Drawings) · Final site drainage should be designed to prevent erosion, concentrated flows to adjacent properties, controlled overflow, and ponding. (See Construction Drawings) Runoff Conveyance System. SWPPP July 2024 Page 10 · Stabilize conveyance system. (See Construction Drawings) · Channels and streambanks need to be seeded at the outlet points. (See Construction Drawings) · Install check dams to slow down the velocity of concentrated flow. (See Construction Drawings) · Protect existing natural drainage systems and streams by maintaining vegetative buffers and by implanting other appropriate practices. (See Construction Drawings) Groundwater Recharge · Install practices to infiltrate the runoff on the site as much as possible. (See Construction Drawings) · Provide groundwater recharge to maintain the hydrologic regime of the downstream water bodies and simulate predevelopment hydrology. (See Construction Drawings) · Use infiltration practices to prevent concentrate flows. (See Construction Drawings) Outlet Stabilization · Install practices to prevent erosion and discharge points. (See Construction Drawings) Step 3: Grading · Limit the initial clearing and earth disturbance to the minimum necessary to install sediment control measures. Excavation for footings, clearing, or other earth disturbance may only take place after the sediment and erosion controls are installed. (See Construction Drawings) · Stockpile the topsoil removed from the site. The topsoil should be protected, stabilized and sited in a location away from the storm drains and waterbodies. (See Construction Drawings) · Changed in grade or removal of vegetation should not disturb established buffers and should not be allowed within any regulated distance from wetlands, the high water line of a body of water affected by tidal action, or other such protected zones. (Disturbance buffers are proposed along wetland boundaries. See Construction Drawings) · Avoid disturbance of steep slopes. (See Construction Drawings) · An undisturbed buffer should be maintained to control runoff from steep slopes within sensitive areas. (See Construction Drawings) · Proposed grading should not impair existing surface drainage resulting in a potential erosion hazard impacting adjacent land or waterbodies. (See Construction Drawings) Step 4: Erosion Control (Stabilization) · Implement erosion control practices to keep the soil in place. (See Construction Drawings and Section 3.0) · Stabilization should be completed immediately for the surface of all perimeter control and perimeter slopes. (See Construction Drawings and Section 3.0 of this report) SWPPP July 2024 Page 11 · When activates temporarily cease during construction, soil stockpiles and exposed soil should be stabilized by seed, mulch or other appropriate measures as soon as possible, but in no case more than 14 days after construction activity has ceased. (See Construction Drawings and Section 3.0 of this report) · Following initial soil disturbance, or re-disturbance, permanent or temporary, stabilization should be completed within 14 days or as soon as possible. (See Construction Drawings and Section 3.0 of this report) · Apply temporary or permanent stabilization measures immediately on all disturbed areas where work is delayed or completed. (See Construction Drawings and Section 3.0 of this report) · Consult the local Soil and Water Conservation District for proper timing and application rate of seed, fertilizer and mulch. (See Construction Drawings and Section 3.0 of this report) Step 5: Sediment Control · At any location where surface runoff from disturbed or graded areas may flow off the construction area, sediment control measures must be installed to prevent sediment from being transported off site. No grading, filling or other disturbance is allowed within existing drainage swales. (See Construction Drawings) · Swales or other areas that transport concentrated flow should be appropriately stabilized. (See Construction Drawings) · Downspout or sump pump discharges must have acceptable outfalls that are protected by splash blocks, sod, or piping as required by site conditions (i.e., no concentrated flow directed over fill slopes) (See Construction Drawings) Step 6: Maintenance and Inspection · Identify the type, number and frequency of maintenance actions required for stormwater management and erosion control during construction and for permanent practices that remain on the site once construction is finalized. (See Construction Drawings, Section 6.0 of this report and Post Construction Maintenance Plan) · Inspection must be indicated on the Construction Sequence Schedule. Inspection must be performed every 7 calendar days and immediately after periods of rainfall greater than 0.5 inch. (See Section 6.0 of this report and Exhibit F.3) · Inspection must verify that all practices are adequately operational, maintained properly and that sediment is removed from all control structures. (See Section 6.0 of this report and Exhibit F) · Inspection must look for evidence of the soil erosion on the site, potential of pollutants entering drainage systems, problems at discharge points (such as turbidity in receiving water), and signs of soil and mud transport from the site to the public road at the entrance. (See Section 6.0 of this report and Construction Drawings) · Routine maintenance must be identified on the schedule and performed on a regular basis and as soon as possible as a problem is identified. (See Section 6.0 of this report, Exhibit E and Construction Drawings) · Identify the person or entities responsible for conducting the maintenance actions during construction and post-construction. (See Section 6.0 of this report, Exhibit F, Post Construction Maintenance Plan and Construction Drawings) · Retain a copy of the inspection and quarterly reports on-site with the SWPPP. SWPPP July 2024 Page 12 (See Exhibit F for Reports) Step 7: Finalize Grading & Landscaping · Identify the final grading and stabilization plan once the construction is completed. (See Construction Drawings) · All open areas, including borrow and spoil areas must be stabilized. (See Construction Drawings) · Plan a permanent top soil, seed, sod, mulch, riprap or other stabilization practice in the remaining disturbed areas as appropriate. (See Construction Drawings) · Stabilization must be undertaken no later than 14 days after construction activities has ceased except as noted in the GP-0-20-001. (See Construction Drawings and Section 3.0) · Remove the temporary control measures. (See Construction Drawings and Section 6.0) Step 8: Post Construction Controls · Identify the permanent structural or non-structural practices that will remain on site. (See Construction Drawings and Post Construction Maintenance Plan) · Ensure that the permanent structural or non-structural practices utilized during construction are properly designed to suit the post-construction site conditions. (See Construction Drawings) · In finalizing the plan, evaluate the post-construction runoff condition on site. (See Section 5.0 of SWMR) · Minimize the risk of concentrated flow and erosion. (See Section 5.0 of SWMR) · On-site runoff controls help reduce the risk of increased runoff velocity, erosion and point source discharge. In addition to the standard runoff and erosion control practices identified in NY Standards for Erosion and Sediment Control, some of the techniques discussed under on-site runoff control discussion may be applied. (See Construction Drawings) Steps 1 through 8 are basic instructional guidelines for preparing a SWPPP for pre construction, during construction and post construction activities for a given site. Site characteristics and construction sequencing will impact the amount of work to be preformed. Additional erosion control practices procedures post maintenance practices are included in the following sections. 2.3 SWPPP Requirements For Water Quality and Water Quantity Control Plans A Water Quality and Water Quantity Control Plan must be designed to meet DEC’s required sizing criteria and pollutant removal goals. These criteria are fully presented in the Chapter 4 and Chapter 5 of NYS Stormwater Management Design Manual. The following provides a list of information and calculations required for completing the water quality and quantity components of the SWPPP. The outline of the following place may also be used by those who choose to deviate from DEC’s standards. Water Quality and Quantity Plan Details (See Section 5.0 of SWMR and Construction Drawings) Select stormwater management practices from the list of approved practices in the Chapter 5 of the Design Manual that suit the future condition of the site. Identify a list of selected practices along with a brief description and site information. Location of these practices must also be identified on a map. The SWPPP must provide dimensional details of proposed practices and include summary tables of corresponding calculations for the design of the selected practices. Use Appendix H of the Design Manual for an example checklist for final stormwater management plan preparation. A. Mapping requirements: · Ensure that in addition to the general features identified previously, maps prepared for the site illustrate at a minimum: ○ Existing and proposed topography (minimum of 2-foot contours recommended) SWPPP July 2024 Page 13 ○ Mapping of predominant soils from USDA soil surveys as well as location of any site-specific borehole investigations that may have been performed ○ Location of existing and proposed conveyance systems such as grass channels, swales, and storm drain and flow paths ○ Location of floodplain/floodway limits and relationship of site to upstream and downstream properties and drainages ○ Location and dimensions of proposed channel modifications, such as bridge or culvert crossings ○ Location, size, maintenance access, and limits of disturbance of proposed structural stormwater management practices (See Exhibits E.3 and E.4 and Construction Drawings for all of the above) · Prepare representative cross-section and profile drawings and details of structural stormwater management practices and conveyances (i.e., storm drains, open channels, etc). Drawings should include: ○ Existing and proposed structural elevations (e.g., invert of pipes, manholes, etc.) ○ Design water surface elevations ○ Structural details of outlet structures, embankments, spillways, stilling basins, grade control structures, conveyance channels, etc ○ Logs of borehole investigations that may have been performed along with supporting geotechnical report (See Exhibits E.3 and E.4 and Construction Drawings for all of the above that applies) B. Hydrologic and hydraulic analysis: Conduct a hydrologic and hydraulic analysis for all structural components of the stormwater system (e.g., storm drains, open channels, swales, management practices, etc.) for applicable design storms. The analysis should include: · Existing condition analysis for time of concentrations, runoff rates, volumes, velocities, and water surface elevations showing methodologies used and supporting calculations. (See Sections 1.0, 3.0 and 5.0 of SWMR and Exhibit A.2) · Proposed condition analysis for time of concentrations, runoff rates, volumes, velocities, water surface elevations, and routing showing the methodologies used and supporting calculations. (See Sections 1.0, 3.0 and 5.0 of SWMR and Exhibit A.3) · Final sizing calculations for structural stormwater management practices including contributing drainage area, storage, and outlet configuration (See Sections 1.0, 3.0 and 5.0 of SWMR and Exhibit C.2) Sizing for Water Quality (WQV) Control: Size the selected practices base on the 90% rule methodology defined in the Chapter 4 of the Design Manual. Identify the numeric values and provide calculations for: WQV=[(P)(RV)(A)] / 12 RV = 0.05+0.009I I = Impervious Cover (Percent) Minimum RV = 0.2 P = 90% Rainfall Event Number (See figure 4.1) A = site area in acres (See Exhibit B for WQv calculations) SWPPP July 2024 Page 14 Sizing for Water Quantity Controls: · Channel Protection (CPV), Default Criterion: CPV = 24-hour extended detention of post-developed, 1-year, 24-hour event. (See Exhibit B and C for WQv calculations) · Channel Protection, Options for Sites Larger than 50 Acres: Distributed Runoff Control – geomorphic assessment to determine the bankfull channel characteristics and thresholds for channel stability and bedload movement. (See Exhibits B and C for calculations) · Sizing for Overbank Flood (Qp): Control the peak discharge from the 10-year storm to 10-year pre- development rates. (See Exhibit C for calculations) · Sizing for Extreme Storm (Qf): Control the peak discharge from the 100-year storm to 100-year pre- development rates. Safely pass the 100-year storm event. (See Exhibit C for calculations) · Stage-discharge or outlet rating curves and inflow and outflow hydrographs for storage facilities (e.g., stormwater ponds and wetlands) (See Exhibit C) · Final analysis of potential downstream impact/effects of project, where necessary (n/a for this project) · Dam breach analysis, where necessary (n/a for this project) C. Finalize landscaping · Final landscaping plans for structural stormwater management practices and any site reforestation or revegetation (Topsoil and Seed and buffering landscape along stormwater practices) · Provide structural calculations and construction specification, where necessary (n/a for this project) D. Maintenance Plan Maintenance plan must include: · Name, address, and phone number of responsible parties for maintenance · Description of annual maintenance tasks · Description of applicable easements · Description of funding source · Minimum vegetative cover requirements · Access and Safety issues · Testing and disposal of sediments that will likely be necessary · Evidence of acquisition of all applicable local and non-local permits · Evidence of acquisition of all necessary legal agreements (e.g., easements, covenants, land trusts) (Post Construction Maintenance Plan section in report) SWPPP July 2024 Page 15 2.4 Construction Sequence Scheduling Prepare a schedule for activities during and after construction. Define the sequence of implementing the E&SC and water quality / quantity control practices identified in your SWPPP. This schedule must identify activities during the period prior to soil disturbance through site stabilization. Also identify the inspection and maintenance measures during and after construction. Quantity of practices may be identified by the number of units or any other type of measures identified in the SWPPP. All the planned activities should be marked corresponding maps. A copy of the schedule along with the maps should be available at the construction site. Type Activites (Identify name of planned practices) Number (Quantity) Map Symbols Estimated Start(Date)----End(Date) ◄─███ ███ ███─► Pre During Post Maintenance Actions 1-Pre- Construction Actions To be determined by Contractor prior to site disturbance 2- Runoff & Drainage Control 3- Grading 4- Erosion Control 5- Sediment Control M6-Maintenance, Inspection & Plan Update 7- Finalize Grading & Landscaping 8- Post construction SW Mgmt. SWPPP July 2024 Page 16 3.0 CONSTRUCTION EROSION CONTROL PRACTICES Listed below are the suggested Temporary Erosion Control Devices that may be required for this site above what is indicated on the Erosion Control Plan in the construction drawings. A SWPPP has been provided for the contractor to follow in the Construction Drawing Plan. The SWPPP is a general guideline for the contractor to follow during the course of construction. The site inspector may/can revise the SWPPP as he/she feels necessary to prevent erodable soils form leaving the construction work area. All anticipated Temporary and Permanent Erosion Control measures required for construction of this project have been shown in the “Construction Drawing” documents. Any modifications to the SWPPP during construction shall be subject to engineer review. The SPDES Permittee will be held responsible for any soil exposure and/or erosion that occurs outside the defined limits of work and haul roads, and will immediately install erosion control measures and stabilize disturbed areas. Furthermore, any fines that could arise as a result of improper implementation of the SWPPP will be the responsibility of the SPDES Permittee. Siltation Fence (Temporary) Silt fence shall be installed and maintained to prevent sediment transport until permanent soil stabilization occurs. The anticipated locations for silt fence placement are shown on the plans. Additional Silt fence may be needed as site conditions warrant. The Contractor and Stormwater Management Inspector are encouraged to identify additional placement opportunities as necessary to maintain the highest water quality standards possible. (See Construction Drawings for typical silt fence installation). Silt fence shall be placed parallel to contours and should not be placed in concentrated flows. Stockpile (Temporary) Topsoil or any other soil excavated during construction shall stockpile in a suitable area clear from any stormwater drainage course. Silt fence will be used to enclose all stockpile areas. Stockpiles which are inactive for more than 14 days shall be temporary seeded. The temporary stockpile shall be protected with a diversion swale if necessary. Seed and Mulch (Temporary) Any disturbed areas that are exposed for than 14 days and not subject to construction traffic will immediately receive temporary seeding. If the season prevents the establishment of the temporary cover the disturbed areas with mulch or straw at rate of 2.0 tons per acre. Construction Entrance (Temporary) Construction entrance shall 50 foot long by 24 feet. The construction entrance captures material and debris before construction vehicles leave the project work zone. (See Construction Drawing for construction entrance installation) Dust Control (Temporary) Water will be applied at a rate to minimize air born particles from leaving the construction site as instructed by inspector. SWPPP July 2024 Page 17 4.0 CONSTRUCTION WASTE MANAGEMENT Material Stockpiles Material resulting from the clearing and grubbing operation will be stockpiled up slope from adequate sedimentation controls. Equipment Cleaning and Maintenance The general Contractor will designate areas for equipment cleaning, maintenance, and repair. The general Contractor and subcontractors will utilize those areas. The areas will be protected by a temporary perimeter berm. Detergents The use of detergents for large-scale washing is prohibited (i.e., vehicles, buildings, pavement surfaces, etc.) Spill Prevention and Response A Spill Prevention and Response Plan shall be developed for the site by the Contractor. The plan shall detail the steps needed to be followed in the event of an accidental spill and shall identify contact names and phone numbers of people and agencies that must be notified. The plan shall include Material Safety Data Sheets (MSDS) for all materials to be stored on-site. All workers on- site will be required to be trained on safe handling and spill prevention procedures for all materials used during construction. Regular tailgate safety meetings shall be held and all workers that are expected on the site during the week shall be required to attend. Concrete Wash Areas Concrete trucks will be allowed to wash out or discharge surplus concrete or drum wash water on the site, but only in specifically designated diked and impervious washout areas which have been prepared to prevent contact between the concrete wash and storm water. Waste generated from concrete wash water shall not be allowed to flow into drainage ways, inlets, receiving waters or highway right of ways, or any location other than the designated Concrete Wash Areas. Proper signage designating the “Concrete Wash Areas” shall be placed near the facility. Concrete Wash Areas shall be located at minimum 100 linear feet from drainage ways, inlets and surface waters. The hardened residue from the Concrete Wash Areas will be disposed of in the same manner as other non- hazardous construction waste materials. Maintenance of the wash area is to include removal of hardened concrete. The facility shall have sufficient volume to contain all the concrete waste resulting from washout and a minimum freeboard of 12 inches. The facility shall not be filled beyond 95% capacity and shall be cleaned out once 75% full unless a new facility is constructed. The Contractor will be responsible for seeing that these procedures are followed. Saw-cut Portland Cement Concrete (PCC) slurry shall not be allowed to enter storm drains or watercourses. Saw-cut residue should not be left on the surface of pavement or be allowed to flow over and off pavement. The Project may require the use of multiple concrete wash areas. All concrete wash areas will be located in an area where the likelihood of the area contributing to storm water discharges is negligible. If required, additional BMPs must be implemented to prevent concrete wastes from contributing to stormwater discharges. Material Storage Construction materials shall be stored in a dedicated staging area. The staging area shall be located in an area that minimizes the impacts of the construction materials effecting stormwater quality. Chemicals, paints, solvents, fertilizers, and other toxic material must be stored in waterproof containers. Except during application, the contents must be kept in trucks or within storage facilities. Runoff containing such material must be collected, removed from the site, treated, and disposed of at an approved solid waste or chemical disposal facility SWPPP July 2024 Page 18 5.0 SEQUENCE OF CONSTRUCTION The following sequence of construction is intended to demonstrate the general order of construction activities to ensuring that no off-site degradation will be caused by erosion within the project limits. The sequencing of construction may be modified as field conditions warrant ensuring environmental compliance and good housekeeping. The general sequence of construction for the project shall be: 1. CONTRACTOR SHALL INSTALL CONSTRUCTION ENTRANCE AND SILT FENCE. 2. TREE REMOVAL AND ROUGH GRADE SITE. 3. INSTALL DRAINAGE SYSTEM, WATER LINE, GRAVITY SEWER, ETC. 4. INSTALL TEMPORARY CATCH BASIN INLET PROTECTION. 5. CONSTRUCT SORMWATER PRACTICES (BASINS, RAIN GARDEN, ETC.) 6. INSTALL SUBBASE FOR PARKING LOT ROADS 7. INSTALL PAVEMENT. 8. SOIL RESTORATION 9. FINISH GRADE AROUND BUILDING AND SEED/INSTALL PLANTING. SOIL RESTORATION 1. APPLY 3 INCHES OF COMPOST OVER SUBSOIL. 2. TILL COMPOST INTO SUBSOIL TO DEPTH OF AT LEAST 12 INCHES USING XCAT-MOUNTED RIPPER, TRACTOR MOUNTED DISC, OR TILLER, MIXING AND CIRCULATING AIR AND COMPOST INTO SUBSOILS. 3. ROCK-PICK UNTIL UPLIFT STONE/ROCK MATERIALS OF FOUR INCHES AND LARGER SIZE ARE CLEANED OFF THE SITE. 4. APPLY TOPSOIL TO DEPTH OF 6 INCHES 5. VEGETATE AS REQUIRED BY APPROVED PLAN. AT THE END OF PROJECT AN INSPECTOR SHOULD BE ABLE TO TO PUSH A 3/8" METAL BAR 12" INCHES INTO SOIL JUST WITH BODY WEIGHT. TILLING (STEP 2 ABOVE) SHOULD NOT BE PERFORMED WITHIN THE DRIP LINE OF ANY EXISTING TREES OR OVER UTILITY INSTALLATIONS THAT ARE WITHIN 24 INCHES OF THE SURFACE. COMPOST SHALL BE AGED, FROM PLANT DERIVED MATERIALS, FREE OF VIABLE WEEDS SEEDS, HAVE NO VISIBLE FREE WATER OR DUST PRODUCED WHEN HANDLING, PASS THROUGH A HALH INCH SCREEN AND HAVE A PH SUITABLE TO GROW DESIRED PLANTS. TOPSOIL SHALL MEET THE SPECIFACTIONS OF NYSDOT TYPE "A" TOPSOIL. THE CONTRACTOR SHALL BE RESPONSIBLE FOR IMPLEMENTING EROSION AND SEDIMENT CONTROL TO PROTECT SURROUNDING WATER BODIES. SWPPP July 2024 Page 19 6.0 EROSION CONTROL MAINTENANCE DURING CONSTRUCTION A certified/qualified inspector shall inspect the site at least once every (7) calendar days. The qualified inspector shall make modifications to the SWPPP as he/she feels the site conditions warrant. The qualified inspector shall complete weekly, monthly and quarterly reports as required by NYSDEC. Weekly, monthly, and quarterly reports can be found in Exhibit F.4. Maintenance of erosion control devices shall follow the recommendations set forth in the “New York Standards and Specifications for Erosion and Sediment Controls” dated July 2016, commonly known as the “Blue Book”. The Contractor must maintain a record of the inspections in a site logbook. The logbook shall be maintained onsite and be made available to authorities upon request. SWPPP July 2024 Page 20 7.0 GENERAL PERMIT (GP-0-20-002) INFORMATION 7.1 Historical Places Stormwater discharge from the site does not affect listed or eligible for listing on State or National Register of Historic Places. See enclosed No affect letter from NYSOPRHP in Exhibit F.6. 7.2 Endangered Species Per NYSDEC EAF mapper, there are no endangered or threatened species areas affected. See letter in Exhibit F.6. 7.3 Notice of Intent Application for a SPDES discharge permit is deemed necessary for the proposed project. The owner shall make application to the New York State Department of Environmental Conservation for the SPDES General Permit (GP-0-20-001). The draft permit application is included as Exhibit F.1.The owner will make a formal submission to NYSDEC for coverage under SPDES General Permit (GP-0-20-001) after local, county and state approvals for this project are granted. 7.4 Notice of Termination After satisfactory completion of the construction of the project, the Owner will file a Notice of Termination of Coverage (NOT) with NYSDEC for the SPDES General Permit (GP-0-20-001). Prior to filing the NOT, the Owner shall have the qualified professional perform a final site inspection. Applications for NOT and Final Stabilization report are included in Exhibit F.5 SWPPP July 2024 Page 21 Exhibits SWPPP July 2024 Page 22 Exhibit F – Stormwater Pollution Prevention Plan (SWPPP) .1 Notice of Intent (NOI) .2 MS4 agreement .3 General Permit .4 Construction Site Log Book .5 Notice of Termination (NOT) .6 NYSOPRHP and NYSDEC Correspondence NOI for coverage under Stormwater General Permit for Construction Activity version 1.39 (Submission #: HQ4-9E7H-JZP94, version 1) Details Originally Started By James W Easton Alternate Identifier Station Park Subdivision Submission ID HQ4-9E7H-JZP94 Submission Reason New Status Draft Form Input Owner/Operator Information Owner/Operator Name (Company/Private Owner/Municipality/Agency/Institution, etc.) Prime Companies Owner/Operator Contact Person Last Name (NOT CONSULTANT) Curley Owner/Operator Contact Person First Name Todd Owner/Operator Mailing Address 621 Columbia Street City Cohoes State New York Zip 12047 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 1/15 Phone 5187859000 Email tcurley@cbcprime.net Federal Tax ID NONE PROVIDED If the owner/operator is an organization, provide the Federal Tax ID number, or Employer Identification Number (EIN), in the format xx-xxxxxxx. If the owner/operator is an individual and not an organization, enter "Not Applicable" or "N/A" and do not provide the individual’s social security number. Project Location Project/Site Name Station Park Subdivision Street Address (Not P.O. Box) NYS Route 29 North City/Town/Village (THAT ISSUES BUILDING PERMIT) Saratoga Springs NY Zip 12866 5 The DEC Region must be provided. Please use the NYSDEC Stormwater Interactive Map (https://gisservices.dec.ny.gov/gis/stormwater/) to confirm which DEC Region this site is located in. To view the DEC Regions, click on “Other Useful Reference Layers” on the left side of the map, then click on “DEC Administrative Boundary.” Zoom out as needed to see the Region boundaries. For projects that span multiple Regions, please select a primary Region and then provide the additional Regions as a note in Question 39. Side of Street State DEC Region 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 2/15 SARATOGA Name of Nearest Cross Street West Ave Distance to Nearest Cross Street (Feet) 500 West Tax Map Numbers Section-Block-Parcel 165-2 Tax Map Numbers 70, 19 and 18 If the project does not have tax map numbers (e.g. linear projects), enter “Not Applicable” or "N/A". 1. Coordinates Provide the Geographic Coordinates for the project site. The two methods are: - Navigate to the project location on the map (below) and click to place a marker and obtain the XY coordinates. - The "Find Me" button will provide the lat/long for the person filling out this form. Then pan the map to the correct location and click the map to place a marker and obtain the XY coordinates. Navigate to your location and click on the map to get the X,Y coordinates 43.08054378663863,-73.80968898277773 Project Details New Construction For the purposes of this eNOI, “New Construction” refers to any project that does not involve the disturbance of existing impervious area (i.e. 0 acres). If existing impervious area will be disturbed on the project site, it is considered redevelopment with either increase in impervious area or no increase in impervious area. 3. Select the predominant land use for both pre and post development conditions. County Project In Relation to Cross Street 2. What is the nature of this project? 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 3/15 Forest Multifamily Residential 3a. If Single Family Subdivision was selected in question 3, enter the number of subdivision lots. 13 4. In accordance with the larger common plan of development or sale, enter the total project site acreage, the acreage to be disturbed and the future impervious area (acreage)within the disturbed area. *** ROUND TO THE NEAREST TENTH OF AN ACRE. *** Total Site Area (acres) 17.6 Total Area to be Disturbed (acres) 16.8 Existing Impervious Area to be Disturbed (acres) 0.1 Future Impervious Area Within Disturbed Area (acres) 11.4 No 6. Indicate the percentage (%) of each Hydrologic Soil Group(HSG) at the site. A (%) 100 B (%) 0 C (%) 0 D (%) 0 Yes Pre-Development Existing Landuse Post-Development Future Land Use 5. Do you plan to disturb more than 5 acres of soil at any one time? 7. Is this a phased project? 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 4/15 8. Enter the planned start and end dates of the disturbance activities. Start Date 10/31/2025 End Date 10/31/2030 9. Identify the nearest surface waterbody(ies) to which construction site runoff will discharge. Geyser Brook Drainage ditches and storm sewer systems are not considered surface waterbodies. Please identify the surface waterbody that they discharge to. If the nearest surface waterbody is unnamed, provide a description of the waterbody, such as, “Unnamed tributary to Niagara River.” Stream/Creek Off Site Other Waterbody Type Off Site Description NONE PROVIDED NONE PROVIDED No No No Please use the DEC Stormwater Interactive Map (https://gisservices.dec.ny.gov/gis/stormwater/) to confirm if this site is located in one of the watersheds of an AA or AA-S classified water. To view the watershed areas, click on “Permit Related Layers” on the left side of the map, then click on “Class AA AAS Watersheds.” If No, skip question 13. 9a. Type of waterbody identified in question 9? 9b. If "wetland" was selected in 9A, how was the wetland identified? 10. Has the surface waterbody(ies) in question 9 been identified as a 303(d) segment in Appendix E of GP-0-20-001? 11. Is this project located in one of the Watersheds identified in Appendix C of GP-0-20- 001? 12. Is the project located in one of the watershed areas associated with AA and AA-S classified waters? 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 5/15 No If Yes, what is the acreage to be disturbed? NONE PROVIDED No Yes 16. What is the name of the municipality/entity that owns the separate storm sewer system? City of Saratoga Springs No No No No Required SWPPP Components Yes Yes If you answered No in question 22, skip question 23 and the Post-construction Criteria and Post-construction SMP Identification sections. 13. Does this construction activity disturb land with no existing impervious cover and where the Soil Slope Phase is identified as D (provided the map unit name is inclusive of slopes greater than 25%), E or F on the USDA Soil Survey? 14. Will the project disturb soils within a State regulated wetland or the protected 100 foot adjacent area? 15. Does the site runoff enter a separate storm sewer system (including roadside drains, swales, ditches, culverts, etc)? 17. Does any runoff from the site enter a sewer classified as a Combined Sewer? 18. Will future use of this site be an agricultural property as defined by the NYS Agriculture and Markets Law? 19. Is this property owned by a state authority, state agency, federal government or local government? 20. Is this a remediation project being done under a Department approved work plan? (i.e. CERCLA, RCRA, Voluntary Cleanup Agreement, etc.) 21. Has the required Erosion and Sediment Control component of the SWPPP been developed in conformance with the current NYS Standards and Specifications for Erosion and Sediment Control (aka Blue Book)? 22. Does this construction activity require the development of a SWPPP that includes the post-construction stormwater management practice component (i.e. Runoff Reduction, Water Quality and Quantity Control practices/techniques)? 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 6/15 Yes Professional Engineer (P.E.) SWPPP Preparer EP Land Services LLC Contact Name (Last, First) James w Easton Mailing Address 621 Columbia Street City Cohoes State New York Zip 12047 Phone 5187859000 Email jeaston@theprimecompanies.com Download SWPPP Preparer Certification Form Please take the following steps to prepare and upload your preparer certification form: 1) Click on the link below to download a blank certification form 2) The certified SWPPP preparer should sign this form 3) Scan the signed form 4) Upload the scanned document Download SWPPP Preparer Certification Form Please upload the SWPPP Preparer Certification NONE PROVIDED Comment NONE PROVIDED Erosion & Sediment Control Criteria 23. Has the post-construction stormwater management practice component of the SWPPP been developed in conformance with the current NYS Stormwater Management Design Manual? 24. The Stormwater Pollution Prevention Plan (SWPPP) was prepared by: 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 7/15 Yes 26. Select all of the erosion and sediment control practices that will be employed on the project site: Check Dams Dust Control Silt Fence Stabilized Construction Entrance Storm Drain Inlet Protection None Mulching Protecting Vegetation Seeding Topsoiling Land Grading Retaining Wall Rock Outlet Protection Other NONE PROVIDED Post-Construction Criteria * IMPORTANT: Completion of Questions 27-39 is not required if response to Question 22 is No. Building Footprint Reduction Preservation of Undisturbed Area All disturbed areas will be restored in accordance with the Soil Restoration requirements in Table 5.3 of the Design Manual (see page 5-22). 28. Provide the total Water Quality Volume (WQv) required for this project (based on final site plan/layout). (Acre-feet) 1.174 29. Post-construction SMP Identification 25. Has a construction sequence schedule for the planned management practices been prepared? Temporary Structural Biotechnical Vegetative Measures Permanent Structural 27. Identify all site planning practices that were used to prepare the final site plan/layout for the project. 27a. Indicate which of the following soil restoration criteria was used to address the requirements in Section 5.1.6("Soil Restoration") of the Design Manual (2010 version). 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 8/15 Use the Post-construction SMP Identification section to identify the RR techniques (Area Reduction), RR techniques(Volume Reduction) and Standard SMPs with RRv Capacity that were used to reduce the Total WQv Required (#28). Identify the SMPs to be used by providing the total impervious area that contributes runoff to each technique/practice selected. For the Area Reduction Techniques, provide the total contributing area (includes pervious area) and, if applicable, the total impervious area that contributes runoff to the technique/practice. Note: Redevelopment projects shall use the Post-Construction SMP Identification section to identify the SMPs used to treat and/or reduce the WQv required. If runoff reduction techniques will not be used to reduce the required WQv, skip to question 33a after identifying the SMPs. 30. Indicate the Total RRv provided by the RR techniques (Area/Volume Reduction) and Standard SMPs with RRv capacity identified in question 29. (acre-feet) 1.131 No If Yes, go to question 36. If No, go to question 32. 32. Provide the Minimum RRv required based on HSG. [Minimum RRv Required = (P) (0.95) (Ai) / 12, Ai=(s) (Aic)] (acre-feet) 0.634 Yes If Yes, go to question 33. Note: Use the space provided in question #39 to summarize the specific site limitations and justification for not reducing 100% of WQv required (#28). A detailed evaluation of the specific site limitations and justification for not reducing 100% of the WQv required (#28) must also be included in the SWPPP. If No, sizing criteria has not been met; therefore, NOI can not be processed. SWPPP preparer must modify design to meet sizing criteria. 33. SMPs Use the Post-construction SMP Identification section to identify the Standard SMPs and, if applicable, the Alternative SMPs to be used to treat the remaining total WQv (=Total WQv Required in #28 - Total RRv Provided in #30). Also, provide the total impervious area that contributes runoff to each practice selected. NOTE: Use the Post-construction SMP Identification section to identify the SMPs used on Redevelopment projects. 31. Is the Total RRv provided (#30) greater than or equal to the total WQv required (#28)? 32a. Is the Total RRv provided (#30) greater than or equal to the Minimum RRv Required (#32)? 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 9/15 33a. Indicate the Total WQv provided (i.e. WQv treated) by the SMPs identified in question #33 and Standard SMPs with RRv Capacity identified in question #29. (acre- feet) 0.043 Note: For the standard SMPs with RRv capacity, the WQv provided by each practice = the WQv calculated using the contributing drainage area to the practice - provided by the practice. (See Table 3.5 in Design Manual) 34. Provide the sum of the Total RRv provided (#30) and the WQv provided (#33a). 1.174 Yes If Yes, go to question 36. If No, sizing criteria has not been met; therefore, NOI can not be processed. SWPPP preparer must modify design to meet sizing criteria. 36. Provide the total Channel Protection Storage Volume (CPv required and provided or select waiver (#36a), if applicable. CPv Required (acre-feet) 0.0 CPv Provided (acre-feet) 0.0 Reduction of the total CPv is achieved on site through runoff reduction techniques or infiltration systems. 37. Provide the Overbank Flood (Qp) and Extreme Flood (Qf) control criteria or select waiver (#37a), if applicable. Overbank Flood Control Criteria (Qp) Pre-Development (CFS) 0.00 Post-Development (CFS) 0.00 Total Extreme Flood Control Criteria (Qf) Pre-Development (CFS) 0.65 35. Is the sum of the RRv provided (#30) and the WQv provided (#33a) greater than or equal to the total WQv required (#28)? 36a. The need to provide channel protection has been waived because: 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 10/15 Post-Development (CFS) 0.44 NONE PROVIDED Yes If Yes, Identify the entity responsible for the long term Operation and Maintenance Prime Companies 39. Use this space to summarize the specific site limitations and justification for not reducing 100% of WQv required (#28). (See question #32a) This space can also be used for other pertinent project information. NONE PROVIDED Post-Construction SMP Identification Runoff Reduction (RR) Techniques, Standard Stormwater Management Practices (SMPs) and Alternative SMPs Identify the Post-construction SMPs to be used by providing the total impervious area that contributes runoff to each technique/practice selected. For the Area Reduction Techniques, provide the total contributing area (includes pervious area) and, if applicable, the total impervious area that contributes runoff to the technique/practice. RR Techniques (Area Reduction) Round to the nearest tenth Total Contributing Acres for Conservation of Natural Area (RR-1) 0 Total Contributing Impervious Acres for Conservation of Natural Area (RR-1) 0 Total Contributing Acres for Sheetflow to Riparian Buffers/Filter Strips (RR-2) 0 Total Contributing Impervious Acres for Sheetflow to Riparian Buffers/Filter Strips (RR- 2) 0 Total Contributing Acres for Tree Planting/Tree Pit (RR-3) 0 37a. The need to meet the Qp and Qf criteria has been waived because: 38. Has a long term Operation and Maintenance Plan for the post-construction stormwater management practice(s) been developed? 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 11/15 Total Contributing Impervious Acres for Tree Planting/Tree Pit (RR-3) 0 Total Contributing Acres for Disconnection of Rooftop Runoff (RR-4) 0 RR Techniques (Volume Reduction) Total Contributing Impervious Acres for Disconnection of Rooftop Runoff (RR-4) 0 Total Contributing Impervious Acres for Vegetated Swale (RR-5) 0 Total Contributing Impervious Acres for Rain Garden (RR-6) 0 Total Contributing Impervious Acres for Stormwater Planter (RR-7) 0 Total Contributing Impervious Acres for Rain Barrel/Cistern (RR-8) 0 Total Contributing Impervious Acres for Porous Pavement (RR-9) 0 Total Contributing Impervious Acres for Green Roof (RR-10) 0 Standard SMPs with RRv Capacity Total Contributing Impervious Acres for Infiltration Trench (I-1) 0 Total Contributing Impervious Acres for Infiltration Basin (I-2) 2.25 Total Contributing Impervious Acres for Dry Well (I-3) 0 Total Contributing Impervious Acres for Underground Infiltration System (I-4) 9.95 Total Contributing Impervious Acres for Bioretention (F-5) 0 Total Contributing Impervious Acres for Dry Swale (O-1) 0 Standard SMPs 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 12/15 Total Contributing Impervious Acres for Micropool Extended Detention (P-1) 0 Total Contributing Impervious Acres for Wet Pond (P-2) 0 Total Contributing Impervious Acres for Wet Extended Detention (P-3) 0 Total Contributing Impervious Acres for Multiple Pond System (P-4) 0 Total Contributing Impervious Acres for Pocket Pond (P-5) 0 Total Contributing Impervious Acres for Surface Sand Filter (F-1) 0 Total Contributing Impervious Acres for Underground Sand Filter (F-2) 0 Total Contributing Impervious Acres for Perimeter Sand Filter (F-3) 0 Total Contributing Impervious Acres for Organic Filter (F-4) 0 Total Contributing Impervious Acres for Shallow Wetland (W-1) 0 Total Contributing Impervious Acres for Extended Detention Wetland (W-2) 0 Total Contributing Impervious Acres for Pond/Wetland System (W-3) 0 Total Contributing Impervious Acres for Pocket Wetland (W-4) 0 Total Contributing Impervious Acres for Wet Swale (O-2) 0.71 Alternative SMPs (DO NOT INCLUDE PRACTICES BEING USED FOR PRETREATMENT ONLY) Total Contributing Impervious Area for Hydrodynamic NONE PROVIDED Total Contributing Impervious Area for Wet Vault NONE PROVIDED 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 13/15 Total Contributing Impervious Area for Media Filter NONE PROVIDED "Other" Alternative SMP? NONE PROVIDED Total Contributing Impervious Area for "Other" NONE PROVIDED Provide the name and manufaturer of the alternative SMPs (i.e. proprietary practice(s)) being used for WQv treatment. Note: Redevelopment projects which do not use RR techniques, shall use questions 28, 29, 33 and 33a to provide SMPs used, total WQv required and total WQv provided for the project. Manufacturer of Alternative SMP NONE PROVIDED Name of Alternative SMP NONE PROVIDED Other Permits None If SPDES Multi-Sector GP, then give permit ID NONE PROVIDED If Other, then identify NONE PROVIDED Yes If "Yes," then indicate Size of Impact, in acres, to the nearest tenth 0.03 42. If this NOI is being submitted for the purpose of continuing or transferring coverage under a general permit for stormwater runoff from construction activities, please indicate the former SPDES number assigned. NONE PROVIDED MS4 SWPPP Acceptance 40. Identify other DEC permits, existing and new, that are required for this project/facility. 41. Does this project require a US Army Corps of Engineers Wetland Permit? 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 14/15 Yes - Please attach the MS4 Acceptance form below If No, skip question 44 Yes MS4 SWPPP Acceptance Form Download Download form from the link below. Complete, sign, and upload. MS4 SWPPP Acceptance Form MS4 Acceptance Form Upload NONE PROVIDED Comment NONE PROVIDED Owner/Operator Certification Owner/Operator Certification Form Download Download the certification form by clicking the link below. Complete, sign, scan, and upload the form. Owner/Operator Certification Form (PDF, 45KB) Upload Owner/Operator Certification Form NONE PROVIDED Comment NONE PROVIDED 43. Is this project subject to the requirements of a regulated, traditional land use control MS4? 44. Has the "MS4 SWPPP Acceptance" form been signed by the principal executive officer or ranking elected official and submitted along with this NOI? 7/15/24, 1:21 PM NYSDEC eBusiness Portal System - NOI for coverage under Stormwater General Permit for Construction Activity. Revision 1 https://nform-prod.dec.ny.gov/app/#/submissionwizard/033b959c-5cf5-4847-8b0a-fb0cb2def004/11 15/15 NYS Department of Environmental Conservation Division of Water 625 Broadway, 4th Floor Albany, New York 12233-3505 MS4 Stormwater Pollution Prevention Plan (SWPPP) Acceptance Form for Construction Activities Seeking Authorization Under SPDES General Permit *(NOTE: Attach Completed Form to Notice Of Intent and Submit to Address Above) I. Project Owner/Operator Information 1.Owner/Operator Name: 2.Contact Person: 3.Street Address: 4. City/State/Zip: II. Project Site Information 5.Project/Site Name: 6.Street Address: 7. City/State/Zip: III. Stormwater Pollution Prevention Plan (SWPPP) Review and Acceptance Information 8.SWPPP Reviewed by: 9.Title/Position: 10.Date Final SWPPP Reviewed and Accepted: IV.Regulated MS4 Information 11.Name of MS4: 12.MS4 SPDES Permit Identification Number: NYR20A 13.Contact Person: 14.Street Address: 15. City/State/Zip: 16.Telephone Number: Page 1 of 2 MS4 SWPPP Acceptance Form - continued V. Certification Statement - MS4 Official (principal executive officer or ranking elected official) or Duly Authorized Representative I hereby certify that the final Stormwater Pollution Prevention Plan (SWPPP) for the construction project identified in question 5 has been reviewed and meets the substantive requirements in the SPDES General Permit For Stormwater Discharges from Municipal Separate Storm Sewer Systems (MS4s). Note: The MS4, through the acceptance of the SWPPP, assumes no responsibility for the accuracy and adequacy of the design included in the SWPPP. In addition, review and acceptance of the SWPPP by the MS4 does not relieve the owner/operator or their SWPPP preparer of responsibility or liability for errors or omissions in the plan. Printed Name: Title/Position: Signature: Date: VI. Additional Information (NYS DEC - MS4 SWPPP Acceptance Form - January 2015) Page 2 of 2 þ{ËìûtYsËK$TÅTåOTTPPO&TIJNITYÐepartnnent *fHnvlranmantattsnseruatiðnNEW YORK STATEDEPARTMENT OF ENVI RONMENTAL CONSERVATIONSPDES GENERAL PERMITFOR STORMWATER D¡SCHARGESFromCONSTRUCTION ACTIVITYPermit No. GP- 0-20-001lssued Pursuant to Article 17, Titles 7, I and Article 70of the Environmental Conservation LawEffective Date: January 29,2020Expiration Date: January 28,2025John J. FergusonChief Permit Administrator/^ zZ -Z-öuthorized SignatureDateAddress: NYS DECDivision of Environmental Permits625 Broadway, 4th FloorAlbany, N.Y. 12233-1750 I PREFACE Pursuant to Section 402 of the Clean Water Act (“CWA”), stormwater discharges from certain construction activities are unlawful unless they are authorized by a National Pollutant Discharge Elimination System (“NPDES”) permit or by a state permit program. New York administers the approved State Pollutant Discharge Elimination System (SPDES) program with permits issued in accordance with the New York State Environmental Conservation Law (ECL) Article 17, Titles 7, 8 and Article 70. An owner or operator of a construction activity that is eligible for coverage under this permit must obtain coverage prior to the commencement of construction activity. Activities that fit the definition of “construction activity”, as defined under 40 CFR 122.26(b)(14)(x), (15)(i), and (15)(ii), constitute construction of a point source and therefore, pursuant to ECL section 17-0505 and 17-0701, the owner or operator must have coverage under a SPDES permit prior to commencing construction activity. The owner or operator cannot wait until there is an actual discharge from the construction site to obtain permit coverage. *Note: The italicized words/phrases within this permit are defined in Appendix A. I NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION SPDES GENERAL PERMIT FOR STORMWATER DISCHARGES FROM CONSTRUCTION ACTIVITIES Table of Contents Part 1. PERMIT COVERAGE AND LIMITATIONS ............................................................. 1 A. Permit Application ................................................................................................. 1 B. Effluent Limitations Applicable to Discharges from Construction Activities ........... 1 C. Post-construction Stormwater Management Practice Requirements .................... 4 D. Maintaining Water Quality ..................................................................................... 8 E. Eligibility Under This General Permit ..................................................................... 9 F. Activities Which Are Ineligible for Coverage Under This General Permit .............. 9 Part II. PERMIT COVERAGE ........................................................................................... 12 A. How to Obtain Coverage ..................................................................................... 12 B. Notice of Intent (NOI) Submittal .......................................................................... 13 C. Permit Authorization ............................................................................................ 13 D. General Requirements For Owners or Operators With Permit Coverage ........... 15 E. Permit Coverage for Discharges Authorized Under GP-0-15-002 ....................... 17 F. Change of Owner or Operator ............................................................................. 17 Part III. STORMWATER POLLUTION PREVENTION PLAN (SWPPP) ........................... 18 A. General SWPPP Requirements .......................................................................... 18 B. Required SWPPP Contents ................................................................................ 20 C. Required SWPPP Components by Project Type ................................................. 24 Part IV. INSPECTION AND MAINTENANCE REQUIREMENTS ..................................... 24 A. General Construction Site Inspection and Maintenance Requirements .............. 24 B. Contractor Maintenance Inspection Requirements ............................................. 24 C. Qualified Inspector Inspection Requirements ...................................................... 25 Part V. TERMINATION OF PERMIT COVERAGE ........................................................... 29 A. Termination of Permit Coverage ......................................................................... 29 Part VI. REPORTING AND RETENTION RECORDS ...................................................... 31 A. Record Retention ................................................................................................ 31 B. Addresses ........................................................................................................... 31 Part VII. STANDARD PERMIT CONDITIONS .................................................................. 31 A. Duty to Comply .................................................................................................... 31 B. Continuation of the Expired General Permit ........................................................ 32 C. Enforcement ........................................................................................................ 32 D. Need to Halt or Reduce Activity Not a Defense................................................... 32 E. Duty to Mitigate ................................................................................................... 33 F. Duty to Provide Information ................................................................................. 33 G. Other Information ................................................................................................ 33 H. Signatory Requirements ...................................................................................... 33 I. Property Rights ................................................................................................... 35 J. Severability.......................................................................................................... 35 K. Requirement to Obtain Coverage Under an Alternative Permit ........................... 35 L. Proper Operation and Maintenance .................................................................... 36 M. Inspection and Entry ........................................................................................... 36 N. Permit Actions ..................................................................................................... 37 O. Definitions ........................................................................................................... 37 P. Re-Opener Clause .............................................................................................. 37 Q. Penalties for Falsification of Forms and Reports ................................................. 37 R. Other Permits ...................................................................................................... 38 APPENDIX A – Acronyms and Definitions ....................................................................... 39 Acronyms ...................................................................................................................... 39 Definitions ..................................................................................................................... 40 APPENDIX B – Required SWPPP Components by Project Type .................................... 48 Table 1.......................................................................................................................... 48 Table 2.......................................................................................................................... 50 APPENDIX C – Watersheds Requiring Enhanced Phosphorus Removal ........................ 52 APPENDIX D – Watersheds with Lower Disturbance Threshold ..................................... 58 APPENDIX E – 303(d) Segments Impaired by Construction Related Pollutant(s) ........... 59 APPENDIX F – List of NYS DEC Regional Offices .......................................................... 65 (Part I) 1 Part 1. PERMIT COVERAGE AND LIMITATIONS A. Permit Application This permit authorizes stormwater discharges to surface waters of the State from the following construction activities identified within 40 CFR Parts 122.26(b)(14)(x), 122.26(b)(15)(i) and 122.26(b)(15)(ii), provided all of the eligibility provisions of this permit are met: 1. Construction activities involving soil disturbances of one (1) or more acres; including disturbances of less than one acre that are part of a larger common plan of development or sale that will ultimately disturb one or more acres of land; excluding routine maintenance activity that is performed to maintain the original line and grade, hydraulic capacity or original purpose of a facility; 2. Construction activities involving soil disturbances of less than one (1) acre where the Department has determined that a SPDES permit is required for stormwater discharges based on the potential for contribution to a violation of a water quality standard or for significant contribution of pollutants to surface waters of the State. 3. Construction activities located in the watershed(s) identified in Appendix D that involve soil disturbances between five thousand (5,000) square feet and one (1) acre of land. B. Effluent Limitations Applicable to Discharges from Construction Activities Discharges authorized by this permit must achieve, at a minimum, the effluent limitations in Part I.B.1. (a) – (f) of this permit. These limitations represent the degree of effluent reduction attainable by the application of best practicable technology currently available. 1. Erosion and Sediment Control Requirements - The owner or operator must select, design, install, implement and maintain control measures to minimize the discharge of pollutants and prevent a violation of the water quality standards. The selection, design, installation, implementation, and maintenance of these control measures must meet the non-numeric effluent limitations in Part I.B.1.(a) – (f) of this permit and be in accordance with the New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016, using sound engineering judgment. Where control measures are not designed in conformance with the design criteria included in the technical standard, the owner or operator must include in the Stormwater Pollution Prevention Plan (“SWPPP”) the reason(s) for the (Part I.B.1) 2 deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the technical standard. a. Erosion and Sediment Controls. Design, install and maintain effective erosion and sediment controls to minimize the discharge of pollutants and prevent a violation of the water quality standards. At a minimum, such controls must be designed, installed and maintained to: (i) Minimize soil erosion through application of runoff control and soil stabilization control measure to minimize pollutant discharges; (ii) Control stormwater discharges, including both peak flowrates and total stormwater volume, to minimize channel and streambank erosion and scour in the immediate vicinity of the discharge points; (iii) Minimize the amount of soil exposed during construction activity; (iv) Minimize the disturbance of steep slopes; (v) Minimize sediment discharges from the site; (vi) Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas and maximize stormwater infiltration to reduce pollutant discharges, unless infeasible; (vii) Minimize soil compaction. Minimizing soil compaction is not required where the intended function of a specific area of the site dictates that it be compacted; (viii) Unless infeasible, preserve a sufficient amount of topsoil to complete soil restoration and establish a uniform, dense vegetative cover; and (ix) Minimize dust. On areas of exposed soil, minimize dust through the appropriate application of water or other dust suppression techniques to control the generation of pollutants that could be discharged from the site. b. Soil Stabilization. In areas where soil disturbance activity has temporarily or permanently ceased, the application of soil stabilization measures must be initiated by the end of the next business day and completed within fourteen (14) days from the date the current soil disturbance activity ceased. For construction sites that directly discharge to one of the 303(d) segments (Part I.B.1.b) 3 listed in Appendix E or is located in one of the watersheds listed in Appendix C, the application of soil stabilization measures must be initiated by the end of the next business day and completed within seven (7) days from the date the current soil disturbance activity ceased. See Appendix A for definition of Temporarily Ceased. c. Dewatering. Discharges from dewatering activities, including discharges from dewatering of trenches and excavations, must be managed by appropriate control measures. d. Pollution Prevention Measures. Design, install, implement, and maintain effective pollution prevention measures to minimize the discharge of pollutants and prevent a violation of the water quality standards. At a minimum, such measures must be designed, installed, implemented and maintained to: (i) Minimize the discharge of pollutants from equipment and vehicle washing, wheel wash water, and other wash waters. This applies to washing operations that use clean water only. Soaps, detergents and solvents cannot be used; (ii) Minimize the exposure of building materials, building products, construction wastes, trash, landscape materials, fertilizers, pesticides, herbicides, detergents, sanitary waste, hazardous and toxic waste, and other materials present on the site to precipitation and to stormwater. Minimization of exposure is not required in cases where the exposure to precipitation and to stormwater will not result in a discharge of pollutants, or where exposure of a specific material or product poses little risk of stormwater contamination (such as final products and materials intended for outdoor use) ; and (iii) Prevent the discharge of pollutants from spills and leaks and implement chemical spill and leak prevention and response procedures. e. Prohibited Discharges. The following discharges are prohibited: (i) Wastewater from washout of concrete; (ii) Wastewater from washout and cleanout of stucco, paint, form release oils, curing compounds and other construction materials; (Part I.B.1.e.iii) 4 (iii) Fuels, oils, or other pollutants used in vehicle and equipment operation and maintenance; (iv) Soaps or solvents used in vehicle and equipment washing; and (v) Toxic or hazardous substances from a spill or other release. f. Surface Outlets. When discharging from basins and impoundments, the outlets shall be designed, constructed and maintained in such a manner that sediment does not leave the basin or impoundment and that erosion at or below the outlet does not occur. C. Post-construction Stormwater Management Practice Requirements 1. The owner or operator of a construction activity that requires post-construction stormwater management practices pursuant to Part III.C. of this permit must select, design, install, and maintain the practices to meet the performance criteria in the New York State Stormwater Management Design Manual (“Design Manual”), dated January 2015, using sound engineering judgment. Where post-construction stormwater management practices (“SMPs”) are not designed in conformance with the performance criteria in the Design Manual, the owner or operator must include in the SWPPP the reason(s) for the deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the technical standard. 2. The owner or operator of a construction activity that requires post-construction stormwater management practices pursuant to Part III.C. of this permit must design the practices to meet the applicable sizing criteria in Part I.C.2.a., b., c. or d. of this permit. a. Sizing Criteria for New Development (i) Runoff Reduction Volume (“RRv”): Reduce the total Water Quality Volume (“WQv”) by application of RR techniques and standard SMPs with RRv capacity. The total WQv shall be calculated in accordance with the criteria in Section 4.2 of the Design Manual. (ii) Minimum RRv and Treatment of Remaining Total WQv: Construction activities that cannot meet the criteria in Part I.C.2.a.(i) of this permit due to site limitations shall direct runoff from all newly constructed impervious areas to a RR technique or standard SMP with RRv capacity unless infeasible. The specific site limitations that prevent the reduction of 100% of the WQv shall be documented in the SWPPP. (Part I.C.2.a.ii) 5 For each impervious area that is not directed to a RR technique or standard SMP with RRv capacity, the SWPPP must include documentation which demonstrates that all options were considered and for each option explains why it is considered infeasible. In no case shall the runoff reduction achieved from the newly constructed impervious areas be less than the Minimum RRv as calculated using the criteria in Section 4.3 of the Design Manual. The remaining portion of the total WQv that cannot be reduced shal l be treated by application of standard SMPs. (iii) Channel Protection Volume (“Cpv”): Provide 24 hour extended detention of the post-developed 1-year, 24-hour storm event; remaining after runoff reduction. The Cpv requirement does not apply when: (1) Reduction of the entire Cpv is achieved by application of runoff reduction techniques or infiltration systems, or (2) The site discharges directly to tidal waters, or fifth order or larger streams. (iv) Overbank Flood Control Criteria (“Qp”): Requires storage to attenuate the post-development 10-year, 24-hour peak discharge rate (Qp) to predevelopment rates. The Qp requirement does not apply when: (1) the site discharges directly to tidal waters or fifth order or larger streams, or (2) A downstream analysis reveals that overbank control is not required. (v) Extreme Flood Control Criteria (“Qf”): Requires storage to attenuate the post-development 100-year, 24-hour peak discharge rate (Qf) to predevelopment rates. The Qf requirement does not apply when: (1) the site discharges directly to tidal waters or fifth order or larger streams, or (2) A downstream analysis reveals that overbank control is not required. b. Sizing Criteria for New Development in Enhanced Phosphorus Removal Watershed (i) Runoff Reduction Volume (RRv): Reduce the total Water Quality Volume (WQv) by application of RR techniques and standard SMPs with RRv capacity. The total WQv is the runoff volume from the 1 -year, 24 hour design storm over the post-developed watershed and shall be (Part I.C.2.b.i) 6 calculated in accordance with the criteria in Section 10.3 of the Design Manual. (ii) Minimum RRv and Treatment of Remaining Total WQv: Construction activities that cannot meet the criteria in Part I.C.2.b.(i) of this permit due to site limitations shall direct runoff from all newly constructed impervious areas to a RR technique or standard SMP with RRv capacity unless infeasible. The specific site limitations that prevent the reduction of 100% of the WQv shall be documented in the SWPPP. For each impervious area that is not directed to a RR technique or standard SMP with RRv capacity, the SWPPP must include documentation which demonstrates that all options were considered and for each option explains why it is considered infeasible. In no case shall the runoff reduction achieved from the newly constructed impervious areas be less than the Minimum RRv as calculated using the criteria in Section 10.3 of the Design Manual. The remaining portion of the total WQv that cannot be reduced shall be treated by application of standard SMPs. (iii) Channel Protection Volume (Cpv): Provide 24 hour extended detention of the post-developed 1-year, 24-hour storm event; remaining after runoff reduction. The Cpv requirement does not apply when: (1) Reduction of the entire Cpv is achieved by application of runoff reduction techniques or infiltration systems, or (2) The site discharges directly to tidal waters, or fifth order or larger streams. (iv) Overbank Flood Control Criteria (Qp): Requires storage to attenuate the post-development 10-year, 24-hour peak discharge rate (Qp) to predevelopment rates. The Qp requirement does not apply when: (1) the site discharges directly to tidal waters or fifth order or larger streams, or (2) A downstream analysis reveals that overbank control is not required. (v) Extreme Flood Control Criteria (Qf): Requires storage to attenuate the post-development 100-year, 24-hour peak discharge rate (Qf) to predevelopment rates. The Qf requirement does not apply when: (1) the site discharges directly to tidal waters or fifth order or larger streams, or (2) A downstream analysis reveals that overbank control is not required. (Part I.C.2.c) 7 c. Sizing Criteria for Redevelopment Activity (i) Water Quality Volume (WQv): The WQv treatment objective for redevelopment activity shall be addressed by one of the following options. Redevelopment activities located in an Enhanced Phosphorus Removal Watershed (see Part III.B.3. and Appendix C of this permit) shall calculate the WQv in accordance with Section 10.3 of the Design Manual. All other redevelopment activities shall calculate the WQv in accordance with Section 4.2 of the Design Manual. (1) Reduce the existing impervious cover by a minimum of 25% of the total disturbed, impervious area. The Soil Restoration criteria in Section 5.1.6 of the Design Manual must be applied to all newly created pervious areas, or (2) Capture and treat a minimum of 25% of the WQv from the disturbed, impervious area by the application of standard SMPs; or reduce 25% of the WQv from the disturbed, impervious area by the application of RR techniques or standard SMPs with RRv capacity., or (3) Capture and treat a minimum of 75% of the WQv from the disturbed, impervious area as well as any additional runoff from tributary areas by application of the alternative practices discussed in Sections 9.3 and 9.4 of the Design Manual., or (4) Application of a combination of 1, 2 and 3 above that provide a weighted average of at least two of the above methods. Application of this method shall be in accordance with the criteria in Section 9.2.1(B) (IV) of the Design Manual. If there is an existing post-construction stormwater management practice located on the site that captures and treats runoff from the impervious area that is being disturbed, the WQv treatment option selected must, at a minimum, provide treatment equal to the treatment that was being provided by the existing practice(s) if that treatment is greater than the treatment required by options 1 – 4 above. (ii) Channel Protection Volume (Cpv): Not required if there are n o changes to hydrology that increase the discharge rate from the project site. (iii) Overbank Flood Control Criteria (Qp): Not required if there are no changes to hydrology that increase the discharge rate from the project site. (iv) Extreme Flood Control Criteria (Qf): Not required if there are no changes to hydrology that increase the discharge rate from the project site (Part I.C.2.d) 8 d. Sizing Criteria for Combination of Redevelopment Activity and New Development Construction projects that include both New Development and Redevelopment Activity shall provide post-construction stormwater management controls that meet the sizing criteria calculated as an aggregate of the Sizing Criteria in Part I.C.2.a. or b. of this permit for the New Development portion of the project and Part I.C.2.c of this permit for Redevelopment Activity portion of the project. D. Maintaining Water Quality The Department expects that compliance with the conditions of this permit will control discharges necessary to meet applicable water quality standards. It shall be a violation of the ECL for any discharge to either cause or contribute to a violation of water quality standards as contained in Parts 700 through 705 of Title 6 of the Official Comp ilation of Codes, Rules and Regulations of the State of New York, such as: 1. There shall be no increase in turbidity that will cause a substantial visible contrast to natural conditions; 2. There shall be no increase in suspended, colloidal or settleable solids that will cause deposition or impair the waters for their best usages; and 3. There shall be no residue from oil and floating substances, nor visible oil film, nor globules of grease. If there is evidence indicating that the stormwater discharges authorized by this permit are causing, have the reasonable potential to cause, or are contributing to a violation of the water quality standards; the owner or operator must take appropriate corrective action in accordance with Part IV.C.5. of this general permit and document in accordance with Part IV.C.4. of this general permit. To address the water quality standard violation the owner or operator may need to provide additional information, include and implement appropriate controls in the SWPPP to correct the problem, or obtain an individual SPDES permit. If there is evidence indicating that despite compliance with the terms and conditions of this general permit it is demonstrated that the stormwater discharges authorized by this permit are causing or contributing to a violation of water quality standards, or if the Department determines that a modification of the permit is necessary to prevent a violation of water quality standards, the authorized discharges will no longer be eligible for coverage under this permit. The Department may require the owner or operator to obtain an individual SPDES permit to continue discharging. (Part I.E) 9 E. Eligibility Under This General Permit 1. This permit may authorize all discharges of stormwater from construction activity to surface waters of the State and groundwaters except for ineligible discharges identified under subparagraph F. of this Part. 2. Except for non-stormwater discharges explicitly listed in the next paragraph, this permit only authorizes stormwater discharges; including stormwater runoff, snowmelt runoff, and surface runoff and drainage, from construction activities. 3. Notwithstanding paragraphs E.1 and E.2 above, the following non-stormwater discharges are authorized by this permit: those listed in 6 NYCRR 750- 1.2(a)(29)(vi), with the following exception: “Discharges from firefighting activities are authorized only when the firefighting activities are emergencies/unplanned”; waters to which other components have not been added that are used to control dust in accordance with the SWPPP ; and uncontaminated discharges from construction site de-watering operations. All non-stormwater discharges must be identified in the SWPPP. Under all circumstances, the owner or operator must still comply with water quality standards in Part I.D of this permit. 4. The owner or operator must maintain permit eligibility to discharge under this permit. Any discharges that are not compliant with the eligibility conditions of this permit are not authorized by the permit and the owner or operator must either apply for a separate permit to cover those ineligible discharges or take steps necessary to make the discharge eligible for coverage. F. Activities Which Are Ineligible for Coverage Under This General Permit All of the following are not authorized by this permit: 1. Discharges after construction activities have been completed and the site has undergone final stabilization; 2. Discharges that are mixed with sources of non-stormwater other than those expressly authorized under subsection E.3. of this Part and identified in the SWPPP required by this permit; 3. Discharges that are required to obtain an individual SPDES permit or another SPDES general permit pursuant to Part VII.K. of this permit; 4. Construction activities or discharges from construction activities that may adversely affect an endangered or threatened species unless the owner or (Part I.F.4) 10 operator has obtained a permit issued pursuant to 6 NYCRR Part 182 for the project or the Department has issued a letter of non -jurisdiction for the project. All documentation necessary to demonstrate eligibility shall be maintained on site in accordance with Part II.D.2 of this permit; 5. Discharges which either cause or contribute to a violation of water quality standards adopted pursuant to the ECL and its accompanying regulations; 6. Construction activities for residential, commercial and institutional projects: a. Where the discharges from the construction activities are tributary to waters of the state classified as AA or AA-s; and b. Which are undertaken on land with no existing impervious cover; and c. Which disturb one (1) or more acres of land designated on the current United States Department of Agriculture (“USDA”) Soil Survey as Soil Slope Phase “D”, (provided the map unit name is inclusive of slopes greater than 25%), or Soil Slope Phase “E” or “F” (regardless of the map unit name), or a combination of the three designations. 7. Construction activities for linear transportation projects and linear utility projects: a. Where the discharges from the construction activities are tributary to waters of the state classified as AA or AA-s; and b. Which are undertaken on land with no existing impervious cover; and c. Which disturb two (2) or more acres of land designated on the current USDA Soil Survey as Soil Slope Phase “D” (provided the map unit name is inclusive of slopes greater than 25%), or Soil Slope Phase “E” or “F” (regardless of the map unit name), or a combination of the three designations. (Part I.F.8) 11 8. Construction activities that have the potential to affect an historic property, unless there is documentation that such impacts have been resolved. The following documentation necessary to demonstrate eligibility with this requirement shall be maintained on site in accordance with Part II.D.2 of this permit and made available to the Department in accordance with Part VII.F of this permit: a. Documentation that the construction activity is not within an archeologically sensitive area indicated on the sensitivity map, and that the construction activity is not located on or immediately adjacent to a property listed or determined to be eligible for listing on the National or State Registers of Historic Places, and that there is no new permanent building on the construction site within the following distances from a building, structure, or object that is more than 50 years old, or if there is such a new permanent building on the construction site within those parameters that NYS Office of Parks, Recreation and Historic Preservation (OPRHP), a Historic Preservation Commission of a Certified Local Government, or a qualified preservation professional has determined that the building, structure, or object more than 50 years old is not historically/archeologically significant. ▪ 1-5 acres of disturbance - 20 feet ▪ 5-20 acres of disturbance - 50 feet ▪ 20+ acres of disturbance - 100 feet, or b. DEC consultation form sent to OPRHP, and copied to the NYS DEC Agency Historic Preservation Officer (APO), and (i) the State Environmental Quality Review (SEQR) Environmental Assessment Form (EAF) with a negative declaration or the Findings Statement, with documentation of OPRHP’s agreement with the resolution; or (ii) documentation from OPRHP that the construction activity will result in No Impact; or (iii) documentation from OPRHP providing a determination of No Adverse Impact; or (iv) a Letter of Resolution signed by the owner/operator, OPRHP and the DEC APO which allows for this construction activity to be eligible for coverage under the general permit in terms of the State Historic Preservation Act (SHPA); or c. Documentation of satisfactory compliance with Section 106 of the National Historic Preservation Act for a coterminous project area: (Part I.F.8.c) 12 (i) No Affect (ii) No Adverse Affect (iii) Executed Memorandum of Agreement, or d. Documentation that: (i) SHPA Section 14.09 has been completed by NYS DEC or another state agency. 9. Discharges from construction activities that are subject to an existing SPDES individual or general permit where a SPDES permit for construction activity has been terminated or denied; or where the owner or operator has failed to renew an expired individual permit. Part II. PERMIT COVERAGE A. How to Obtain Coverage 1. An owner or operator of a construction activity that is not subject to the requirements of a regulated, traditional land use control MS4 must first prepare a SWPPP in accordance with all applicable requirements of this permit and then submit a completed Notice of Intent (NOI) to the Department to be authorized to discharge under this permit. 2. An owner or operator of a construction activity that is subject to the requirements of a regulated, traditional land use control MS4 must first prepare a SWPPP in accordance with all applicable requirements of this permit and then have the SWPPP reviewed and accepted by the regulated, traditional land use control MS4 prior to submitting the NOI to the Department. The owner or operator shall have the “MS4 SWPPP Acceptance” form signed in accordance with Part VII.H., and then submit that form along with a completed NOI to the Department. 3. The requirement for an owner or operator to have its SWPPP reviewed and accepted by the regulated, traditional land use control MS4 prior to submitting the NOI to the Department does not apply to an owner or operator that is obtaining permit coverage in accordance with the requirements in Part II.F. (Change of Owner or Operator) or where the owner or operator of the construction activity is the regulated, traditional land use control MS4 . This exemption does not apply to construction activities subject to the New York City Administrative Code. (Part II.B) 13 B. Notice of Intent (NOI) Submittal 1. Prior to December 21, 2020, an owner or operator shall use either the electronic (eNOI) or paper version of the NOI that the Department prepared. Both versions of the NOI are located on the Department’s website (http://www.dec.ny.gov/ ). The paper version of the NOI shall be signed in accordance with Part VII.H. of this permit and submitted to the following address: NOTICE OF INTENT NYS DEC, Bureau of Water Permits 625 Broadway, 4th Floor Albany, New York 12233-3505 2. Beginning December 21, 2020 and in accordance with EPA’s 2015 NPDES Electronic Reporting Rule (40 CFR Part 127), the owner or operator must submit the NOI electronically using the Department’s online NOI. 3. The owner or operator shall have the SWPPP preparer sign the “SWPPP Preparer Certification” statement on the NOI prior to submitting the form to the Department. 4. As of the date the NOI is submitted to the Department, the owner or operator shall make the NOI and SWPPP available for review and copying in accordance with the requirements in Part VII.F. of this permit. C. Permit Authorization 1. An owner or operator shall not commence construction activity until their authorization to discharge under this permit goes into effect. 2. Authorization to discharge under this permit will be effective when the owner or operator has satisfied all of the following criteria: a. project review pursuant to the State Environmental Quality Review Act (“SEQRA”) have been satisfied, when SEQRA is applicable. See the Department’s website (http://www.dec.ny.gov/) for more information, b. where required, all necessary Department permits subject to the Uniform Procedures Act (“UPA”) (see 6 NYCRR Part 621), or the equivalent from another New York State agency, have been obtained, unless otherwise notified by the Department pursuant to 6 NYCRR 621.3(a)(4). Owners or operators of construction activities that are required to obtain UPA permits (Part II.C.2.b) 14 must submit a preliminary SWPPP to the appropriate DEC Permit Administrator at the Regional Office listed in Appendix F at the time all other necessary UPA permit applications are submitted. The preliminary SWPPP must include sufficient information to demonstrate that the construction activity qualifies for authorization under this permit, c. the final SWPPP has been prepared, and d. a complete NOI has been submitted to the Department in accordance with the requirements of this permit. 3. An owner or operator that has satisfied the requirements of Part II.C.2 above will be authorized to discharge stormwater from their construction activity in accordance with the following schedule: a. For construction activities that are not subject to the requirements of a regulated, traditional land use control MS4: (i) Five (5) business days from the date the Department receives a complete electronic version of the NOI (eNOI) for construction activities with a SWPPP that has been prepared in conformance with the design criteria in the technical standard referenced in Part III.B.1 and the performance criteria in the technical standard referenced in Parts III.B., 2 or 3, for construction activities that require post-construction stormwater management practices pursuant to Part III.C.; or (ii) Sixty (60) business days from the date the Department receives a complete NOI (electronic or paper version) for construction activities with a SWPPP that has not been prepared in conformance with the design criteria in technical standard referenced in Part III.B.1. or, for construction activities that require post-construction stormwater management practices pursuant to Part III.C., the performance criteria in the technical standard referenced in Parts III.B., 2 or 3, or; (iii) Ten (10) business days from the date the Department receives a complete paper version of the NOI for construction activities with a SWPPP that has been prepared in conformance with the design criteria in the technical standard referenced in Part III.B.1 and the performance criteria in the technical standard referenced in Parts III.B., 2 or 3, for construction activities that require post-construction stormwater management practices pursuant to Part III.C. (Part II.C.3.b) 15 b. For construction activities that are subject to the requirements of a regulated, traditional land use control MS4: (i) Five (5) business days from the date the Department receives both a complete electronic version of the NOI (eNOI) and signed “MS4 SWPPP Acceptance” form, or (ii) Ten (10) business days from the date the Department receives both a complete paper version of the NOI and signed “MS4 SWPPP Acceptance” form. 4. Coverage under this permit authorizes stormwater discharges from only those areas of disturbance that are identified in the NOI. If an owner or operator wishes to have stormwater discharges from future or additional areas of disturbance authorized, they must submit a new NOI that addresses that phase of the development, unless otherwise notified by the Department. The owner or operator shall not commence construction activity on the future or additional areas until their authorization to discharge under this permit goes into effect in accordance with Part II.C. of this permit. D. General Requirements For Owners or Operators With Permit Coverage 1. The owner or operator shall ensure that the provisions of the SWPPP are implemented from the commencement of construction activity until all areas of disturbance have achieved final stabilization and the Notice of Termination (“NOT”) has been submitted to the Department in accordance with Part V. of this permit. This includes any changes made to the SWPPP pursuant to Part III.A.4. of this permit. 2. The owner or operator shall maintain a copy of the General Permit (GP-0-20- 001), NOI, NOI Acknowledgment Letter, SWPPP, MS4 SWPPP Acceptance form, inspection reports, responsible contractor’s or subcontractor’s certification statement (see Part III.A.6.), and all documentation necessary to demonstrate eligibility with this permit at the construction site until all disturbed areas have achieved final stabilization and the NOT has been submitted to the Department. The documents must be maintained in a secure location, such as a job trailer, on-site construction office, or mailbox with lock. The secure location must be accessible during normal business hours to an individual performing a compliance inspection. 3. The owner or operator of a construction activity shall not disturb greater than five (5) acres of soil at any one time without prior written authorization from the Department or, in areas under the jurisdiction of a regulated, traditional land (Part II.D.3) 16 use control MS4, the regulated, traditional land use control MS4 (provided the regulated, traditional land use control MS4 is not the owner or operator of the construction activity). At a minimum, the owner or operator must comply with the following requirements in order to be authorized to disturb greater than fi ve (5) acres of soil at any one time: a. The owner or operator shall have a qualified inspector conduct at least two (2) site inspections in accordance with Part IV.C. of this permit every seven (7) calendar days, for as long as greater than five (5) acres of soil remain disturbed. The two (2) inspections shall be separated by a minimum of two (2) full calendar days. b. In areas where soil disturbance activity has temporarily or permanently ceased, the application of soil stabilization measures must be initiated by the end of the next business day and completed within seven (7) days from the date the current soil disturbance activity ceased. The soil stabilization measures selected shall be in conformance with the technical standard, New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016. c. The owner or operator shall prepare a phasing plan that defines maximum disturbed area per phase and shows required cuts and fills. d. The owner or operator shall install any additional site-specific practices needed to protect water quality. e. The owner or operator shall include the requirements above in their SWPPP. 4. In accordance with statute, regulations, and the terms and conditions of this permit, the Department may suspend or revoke an owner’s or operator’s coverage under this permit at any time if the Department determines that the SWPPP does not meet the permit requirements or consistent with Part VII.K.. 5. Upon a finding of significant non-compliance with the practices described in the SWPPP or violation of this permit, the Department may order an immediate stop to all activity at the site until the non-compliance is remedied. The stop work order shall be in writing, describe the non-compliance in detail, and be sent to the owner or operator. 6. For construction activities that are subject to the requirements of a regulated, traditional land use control MS4, the owner or operator shall notify the (Part II.D.6) 17 regulated, traditional land use control MS4 in writing of any planned amendments or modifications to the post-construction stormwater management practice component of the SWPPP required by Part III.A. 4. and 5. of this permit. Unless otherwise notified by the regulated, traditional land use control MS4, the owner or operator shall have the SWPPP amendments or modifications reviewed and accepted by the regulated, traditional land use control MS4 prior to commencing construction of the post-construction stormwater management practice. E. Permit Coverage for Discharges Authorized Under GP-0-15-002 1. Upon renewal of SPDES General Permit for Stormwater Discharges from Construction Activity (Permit No. GP-0-15-002), an owner or operator of a construction activity with coverage under GP-0-15-002, as of the effective date of GP- 0-20-001, shall be authorized to discharge in accordance with GP- 0-20- 001, unless otherwise notified by the Department. An owner or operator may continue to implement the technical/design components of the post-construction stormwater management controls provided that such design was done in conformance with the technical standards in place at the time of initial project authorization. However, they must comply with the other, non-design provisions of GP-0-20-001. F. Change of Owner or Operator 1. When property ownership changes or when there is a change in operational control over the construction plans and specifications, the original owner or operator must notify the new owner or operator, in writing, of the requirement to obtain permit coverage by submitting a NOI with the Department. For construction activities subject to the requirements of a regulated, traditional land use control MS4, the original owner or operator must also notify the MS4, in writing, of the change in ownership at least 30 calendar days prior to the change in ownership. 2. Once the new owner or operator obtains permit coverage, the original owner or operator shall then submit a completed NOT with the name and permit identification number of the new owner or operator to the Department at the address in Part II.B.1. of this permit. If the original owner or operator maintains ownership of a portion of the construction activity and will disturb soil, they must maintain their coverage under the permit. 3. Permit coverage for the new owner or operator will be effective as of the date the Department receives a complete NOI, provided the original owner or (Part II.F.3) 18 operator was not subject to a sixty (60) business day authorization period that has not expired as of the date the Department receives the NOI from the new owner or operator. Part III. STORMWATER POLLUTION PREVENTION PLAN (SWPPP) A. General SWPPP Requirements 1. A SWPPP shall be prepared and implemented by the owner or operator of each construction activity covered by this permit. The SWPPP must document the selection, design, installation, implementation and maintenance of the control measures and practices that will be used to meet the effluent limitations in Part I.B. of this permit and where applicable, the post-construction stormwater management practice requirements in Part I.C. of this permit. The SWPPP shall be prepared prior to the submittal of the NOI. The NOI shall be submitted to the Department prior to the commencement of construction activity. A copy of the completed, final NOI shall be included in the SWPPP. 2. The SWPPP shall describe the erosion and sediment control practices and where required, post-construction stormwater management practices that will be used and/or constructed to reduce the pollutants in stormwater discharges and to assure compliance with the terms and conditions of this permit. In addition, the SWPPP shall identify potential sources of pollution which may reasonably be expected to affect the quality of stormwater discharges. 3. All SWPPPs that require the post-construction stormwater management practice component shall be prepared by a qualified professional that is knowledgeable in the principles and practices of stormwater management and treatment. 4. The owner or operator must keep the SWPPP current so that it at all times accurately documents the erosion and sediment controls practices that are being used or will be used during construction, and all post-construction stormwater management practices that will be constructed on the site. At a minimum, the owner or operator shall amend the SWPPP, including construction drawings: a. whenever the current provisions prove to be ineffective in minimizing pollutants in stormwater discharges from the site; (Part III.A.4.b) 19 b. whenever there is a change in design, construction, or operation at the construction site that has or could have an effect on the discharge of pollutants; c. to address issues or deficiencies identified during an inspection by the qualified inspector, the Department or other regulatory authority; and d. to document the final construction conditions. 5. The Department may notify the owner or operator at any time that the SWPPP does not meet one or more of the minimum requirements of this permit. The notification shall be in writing and identify the provisions of the SWPPP that require modification. Within fourteen (14) calendar days of such notificati on, or as otherwise indicated by the Department, the owner or operator shall make the required changes to the SWPPP and submit written notification to the Department that the changes have been made. If the owner or operator does not respond to the Department’s comments in the specified time frame, the Department may suspend the owner’s or operator’s coverage under this permit or require the owner or operator to obtain coverage under an individual SPDES permit in accordance with Part II.D.4. of this permit. 6. Prior to the commencement of construction activity, the owner or operator must identify the contractor(s) and subcontractor(s) that will be responsible for installing, constructing, repairing, replacing, inspecting and maintaining the erosion and sediment control practices included in the SWPPP; and the contractor(s) and subcontractor(s) that will be responsible for constructing the post-construction stormwater management practices included in the SWPPP. The owner or operator shall have each of the contractors and subcontractors identify at least one person from their company that will be responsible for implementation of the SWPPP. This person shall be known as the trained contractor. The owner or operator shall ensure that at least one trained contractor is on site on a daily basis when soil disturbance activities are being performed. The owner or operator shall have each of the contractors and subcontractors identified above sign a copy of the following certification statement below before they commence any construction activity: "I hereby certify under penalty of law that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspector during a site inspection. I also understand that the owner or operator must comply with (Part III.A.6) 20 the terms and conditions of the most current version of the New York State Pollutant Discharge Elimination System ("SPDES") general permit for stormwater discharges from construction activities and that it is unlawful for any person to cause or contribute to a violation of water quality standards. Furthermore, I am aware that there are significant penalties for submitting false information, that I do not believe to be true, including the possibility of fine and imprisonment for knowing violations" In addition to providing the certification statement above, the certification page must also identify the specific elements of the SWPPP that each contractor and subcontractor will be responsible for and include the name and title of the person providing the signature; the name and title of the trained contractor responsible for SWPPP implementation; the name, address and telephone number of the contracting firm; the address (or other identifying description) of the site; and the date the certification statement is signed. The owner or operator shall attach the certification statement(s) to the copy of the SWPPP that is maintained at the construction site. If new or additional contractors are hired to implement measures identified in the SWPPP after construction has commenced, they must also sign the certification statement and provide the information listed above. 7. For projects where the Department requests a copy of the SWPPP or inspection reports, the owner or operator shall submit the documents in both electronic (PDF only) and paper format within five (5) business days, unless otherwise notified by the Department. B. Required SWPPP Contents 1. Erosion and sediment control component - All SWPPPs prepared pursuant to this permit shall include erosion and sediment control practices designed in conformance with the technical standard, New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016. Where erosion and sediment control practices are not designed in conformance with the design criteria included in the technical standard, the owner or operator must demonstrate equivalence to the technical standard. At a minimum, the erosion and sediment control component of the SWPPP shall include the following: a. Background information about the scope of the project, including the location, type and size of project (Part III.B.1.b) 21 b. A site map/construction drawing(s) for the project, including a general location map. At a minimum, the site map shall show the total site area; all improvements; areas of disturbance; areas that will not be disturbed; existing vegetation; on-site and adjacent off-site surface water(s); floodplain/floodway boundaries; wetlands and drainage patterns that could be affected by the construction activity; existing and final contours ; locations of different soil types with boundaries; material, waste, borrow or equipment storage areas located on adjacent properties; and location(s) of the stormwater discharge(s); c. A description of the soil(s) present at the site, including an identification of the Hydrologic Soil Group (HSG); d. A construction phasing plan and sequence of operations describing the intended order of construction activities, including clearing and grubbing, excavation and grading, utility and infrastructure installation and any other activity at the site that results in soil disturbance; e. A description of the minimum erosion and sediment control practices to be installed or implemented for each construction activity that will result in soil disturbance. Include a schedule that identifies the timing of initial placement or implementation of each erosion and sediment control practice and the minimum time frames that each practice should remain in place or be implemented; f. A temporary and permanent soil stabilization plan that meets the requirements of this general permit and the technical standard, New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016, for each stage of the project, including initial land clearing and grubbing to project completion and achievement of final stabilization; g. A site map/construction drawing(s) showing the specific location(s), size(s), and length(s) of each erosion and sediment control practice; h. The dimensions, material specifications, installation details, and operation and maintenance requirements for all erosion and sediment control practices. Include the location and sizing of any temporary sediment basins and structural practices that will be used to divert flows from exposed soils; i. A maintenance inspection schedule for the contractor(s) identified in Part III.A.6. of this permit, to ensure continuous and effective operation of the erosion and sediment control practices. The maintenance inspection (Part III.B.1.i) 22 schedule shall be in accordance with the requirements in the technical standard, New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016; j. A description of the pollution prevention measures that will be used to control litter, construction chemicals and construction debris from becoming a pollutant source in the stormwater discharges; k. A description and location of any stormwater discharges associated with industrial activity other than construction at the site, including, but not limited to, stormwater discharges from asphalt plants and concrete plants located on the construction site; and l. Identification of any elements of the design that are not in conformance with the design criteria in the technical standard, New York State Standards and Specifications for Erosion and Sediment Control, dated November 2016. Include the reason for the deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the technical standard. 2. Post-construction stormwater management practice component – The owner or operator of any construction project identified in Table 2 of Appendix B as needing post-construction stormwater management practices shall prepare a SWPPP that includes practices designed in conformance with the applicable sizing criteria in Part I.C.2.a., c. or d. of this permit and the performance criteria in the technical standard, New York State Stormwater Management Design Manual dated January 2015 Where post-construction stormwater management practices are not designed in conformance with the performance criteria in the technical standard, the owner or operator must include in the SWPPP the reason(s) for the deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the technical standard. The post-construction stormwater management practice component of the SWPPP shall include the following: a. Identification of all post-construction stormwater management practices to be constructed as part of the project. Include the dimensions, material specifications and installation details for each post-construction stormwater management practice; (Part III.B.2.b) 23 b. A site map/construction drawing(s) showing the specific location and size of each post-construction stormwater management practice; c. A Stormwater Modeling and Analysis Report that includes: (i) Map(s) showing pre-development conditions, including watershed/subcatchments boundaries, flow paths/routing, and design points; (ii) Map(s) showing post-development conditions, including watershed/subcatchments boundaries, flow paths/routing, design points and post-construction stormwater management practices; (iii) Results of stormwater modeling (i.e. hydrology and hydraulic analysis) for the required storm events. Include supporting calculations (model runs), methodology, and a summary table that compares pre and post - development runoff rates and volumes for the different storm events; (iv) Summary table, with supporting calculations, which demonstrates that each post-construction stormwater management practice has been designed in conformance with the sizing criteria included in the Design Manual; (v) Identification of any sizing criteria that is not required based on the requirements included in Part I.C. of this permit; and (vi) Identification of any elements of the design that are not in conformance with the performance criteria in the Design Manual. Include the reason(s) for the deviation or alternative design and provide information which demonstrates that the deviation or alt ernative design is equivalent to the Design Manual; d. Soil testing results and locations (test pits, borings); e. Infiltration test results, when required; and f. An operations and maintenance plan that includes inspection and maintenance schedules and actions to ensure continuous and effective operation of each post-construction stormwater management practice. The plan shall identify the entity that will be responsible for the long term operation and maintenance of each practice. (Part III.B.3) 24 3. Enhanced Phosphorus Removal Standards - All construction projects identified in Table 2 of Appendix B that are located in the watersheds identified in Appendix C shall prepare a SWPPP that includes post -construction stormwater management practices designed in conformance with the applicable sizing criteria in Part I.C.2. b., c. or d. of this permit and the performance criteria, Enhanced Phosphorus Removal Standards included in the Design Manual. At a minimum, the post-construction stormwater management practice component of the SWPPP shall include items 2.a - 2.f. above. C. Required SWPPP Components by Project Type Unless otherwise notified by the Department, owners or operators of construction activities identified in Table 1 of Appendix B are required to prepare a SWPPP that only includes erosion and sediment control practices designed in conformance with Part III.B.1 of this permit. Owners or operators of the construction activities identified in Table 2 of Appendix B shall prepare a SWPPP that also includes post-construction stormwater management practices designed in conformance with Part III.B.2 or 3 of this permit. Part IV. INSPECTION AND MAINTENANCE REQUIREMENTS A. General Construction Site Inspection and Maintenance Requirements 1. The owner or operator must ensure that all erosion and sediment control practices (including pollution prevention measures) and all post-construction stormwater management practices identified in the SWPPP are inspected and maintained in accordance with Part IV.B. and C. of this permit. 2. The terms of this permit shall not be construed to prohibit the State of New York from exercising any authority pursuant to the ECL, common law or federal law, or prohibit New York State from taking any measures, whether civil or criminal, to prevent violations of the laws of the State of New York or protect the public health and safety and/or the environment. B. Contractor Maintenance Inspection Requirements 1. The owner or operator of each construction activity identified in Tables 1 and 2 of Appendix B shall have a trained contractor inspect the erosion and sediment control practices and pollution prevention measures being implemented within the active work area daily to ensure that they are being maintained in effective operating condition at all times. If deficiencies are identified, the contractor shall (Part IV.B.1) 25 begin implementing corrective actions within one business day and shall complete the corrective actions in a reasonable time frame. 2. For construction sites where soil disturbance activities have been temporarily suspended (e.g. winter shutdown) and temporary stabilization measures have been applied to all disturbed areas, the trained contractor can stop conducting the maintenance inspections. The trained contractor shall begin conducting the maintenance inspections in accordance with Part IV.B.1. of this permit as soon as soil disturbance activities resume. 3. For construction sites where soil disturbance activities have been shut down with partial project completion, the trained contractor can stop conducting the maintenance inspections if all areas disturbed as of the project shutdown date have achieved final stabilization and all post-construction stormwater management practices required for the completed portion of the project have been constructed in conformance with the SWPPP and are operational. C. Qualified Inspector Inspection Requirements The owner or operator shall have a qualified inspector conduct site inspections in conformance with the following requirements: [Note: The trained contractor identified in Part III.A.6. and IV.B. of this permit cannot conduct the qualified inspector site inspections unless they meet the qualified inspector qualifications included in Appendix A. In order to perform these inspections, the trained contractor would have to be a: ▪ licensed Professional Engineer, ▪ Certified Professional in Erosion and Sediment Control (CPESC), ▪ New York State Erosion and Sediment Control Certificate Program holder ▪ Registered Landscape Architect, or ▪ someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided they have received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity]. 1. A qualified inspector shall conduct site inspections for all construction activities identified in Tables 1 and 2 of Appendix B, with the exception of: a. the construction of a single family residential subdivision with 25% or less impervious cover at total site build-out that involves a soil disturbance of one (1) or more acres of land but less than five (5) acres and is not located (Part IV.C.1.a) 26 in one of the watersheds listed in Appendix C and not directly discharging to one of the 303(d) segments listed in Appendix E; b. the construction of a single family home that involves a soil disturbance of one (1) or more acres of land but less than five (5) acres and is not located in one of the watersheds listed in Appendix C and not directly discharging to one of the 303(d) segments listed in Appendix E; c. construction on agricultural property that involves a soil disturbance of one (1) or more acres of land but less than five (5) acres; and d. construction activities located in the watersheds identified in Appendix D that involve soil disturbances between five thousand (5,000) square feet and one (1) acre of land. 2. Unless otherwise notified by the Department, the qualified inspector shall conduct site inspections in accordance with the following timetable: a. For construction sites where soil disturbance activities are on-going, the qualified inspector shall conduct a site inspection at least once every seven (7) calendar days. b. For construction sites where soil disturbance activities are on-going and the owner or operator has received authorization in accordance with Part II.D.3 to disturb greater than five (5) acres of soil at any one time, the qualified inspector shall conduct at least two (2) site inspections every seven (7) calendar days. The two (2) inspections shall be separated by a minimum of two (2) full calendar days. c. For construction sites where soil disturbance activities have been temporarily suspended (e.g. winter shutdown) and temporary stabilization measures have been applied to all disturbed areas, the qualified inspector shall conduct a site inspection at least once every thirty (30) calendar days. The owner or operator shall notify the DOW Water (SPDES) Program contact at the Regional Office (see contact information in Appendix F) or, in areas under the jurisdiction of a regulated, traditional land use control MS4, the regulated, traditional land use control MS4 (provided the regulated, traditional land use control MS4 is not the owner or operator of the construction activity) in writing prior to reducing the frequency of inspections. (Part IV.C.2.d) 27 d. For construction sites where soil disturbance activities have been shut down with partial project completion, the qualified inspector can stop conducting inspections if all areas disturbed as of the project shutdown date have achieved final stabilization and all post-construction stormwater management practices required for the completed portion of the project have been constructed in conformance with the SWPPP and are operational. The owner or operator shall notify the DOW Water (SPDES) Program contact at the Regional Office (see contact information in Appendix F) or, in areas under the jurisdiction of a regulated, traditional land use control MS4, the regulated, traditional land use control MS4 (provided the regulated, traditional land use control MS4 is not the owner or operator of the construction activity) in writing prior to the shutdown. If soil disturbance activities are not resumed within 2 years from the date of shutdown, the owner or operator shall have the qualified inspector perform a final inspection and certify that all disturbed areas have achieved final stabilization, and all temporary, structural erosion and sediment control measures have been removed; and that all post-construction stormwater management practices have been constructed in conformance with the SWPPP by signing the “Final Stabilization” and “Post-Construction Stormwater Management Practice” certification statements on the NOT. The owner or operator shall then submit the completed NOT form to the address in Part II.B.1 of this permit. e. For construction sites that directly discharge to one of the 303(d) segments listed in Appendix E or is located in one of the watersheds listed in Appendix C, the qualified inspector shall conduct at least two (2) site inspections every seven (7) calendar days. The two (2) inspections shall be separated by a minimum of two (2) full calendar days. 3. At a minimum, the qualified inspector shall inspect all erosion and sediment control practices and pollution prevention measures to ensure integrity and effectiveness, all post-construction stormwater management practices under construction to ensure that they are constructed in conformance with the SWPPP, all areas of disturbance that have not achieved final stabilization, all points of discharge to natural surface waterbodies located within, or immediately adjacent to, the property boundaries of the construction site, and all points of discharge from the construction site. 4. The qualified inspector shall prepare an inspection report subsequent to each and every inspection. At a minimum, the inspection report shall includ e and/or address the following: (Part IV.C.4.a) 28 a. Date and time of inspection; b. Name and title of person(s) performing inspection; c. A description of the weather and soil conditions (e.g. dry, wet, saturated) at the time of the inspection; d. A description of the condition of the runoff at all points of discharge from the construction site. This shall include identification of any discharges of sediment from the construction site. Include discharges from conveyance systems (i.e. pipes, culverts, ditches, etc.) and overland flow; e. A description of the condition of all natural surface waterbodies located within, or immediately adjacent to, the property boundaries of the construction site which receive runoff from disturbed areas. This shall include identification of any discharges of sediment to the surface waterbody; f. Identification of all erosion and sediment control practices and pollution prevention measures that need repair or maintenance; g. Identification of all erosion and sediment control practices and pollution prevention measures that were not installed properly or are not functioning as designed and need to be reinstalled or replaced; h. Description and sketch of areas with active soil disturbance activity, areas that have been disturbed but are inactive at the time of the inspection, and areas that have been stabilized (temporary and/or final) since the last inspection; i. Current phase of construction of all post-construction stormwater management practices and identification of all construction that is not in conformance with the SWPPP and technical standards; j. Corrective action(s) that must be taken to install, repair, replace or maintain erosion and sediment control practices and pollution prevention measures; and to correct deficiencies identified with the construction of the post- construction stormwater management practice(s); k. Identification and status of all corrective actions that were required by previous inspection; and (Part IV.C.4.l) 29 l. Digital photographs, with date stamp, that clearly show the condition of all practices that have been identified as needing corrective actions. The qualified inspector shall attach paper color copies of the digital photographs to the inspection report being maintained onsite within seven (7) calendar days of the date of the inspection. The qualified inspector shall also take digital photographs, with date stamp, that clearly show the condition of the practice(s) after the corrective action has been completed. The qualified inspector shall attach paper color copies of the digital photographs to the inspection report that documents the completion of the corrective action work within seven (7) calendar days of that inspection. 5. Within one business day of the completion of an inspection, the qualified inspector shall notify the owner or operator and appropriate contractor or subcontractor identified in Part III.A.6. of this permit of any corrective actions that need to be taken. The contractor or subcontractor shall begin implementing the corrective actions within one business day of this notification and shall complete the corrective actions in a reasonable time frame. 6. All inspection reports shall be signed by the qualified inspector. Pursuant to Part II.D.2. of this permit, the inspection reports shall be maintained on site with the SWPPP. Part V. TERMINATION OF PERMIT COVERAGE A. Termination of Permit Coverage 1. An owner or operator that is eligible to terminate coverage under this permit must submit a completed NOT form to the address in Part II.B.1 of this permit. The NOT form shall be one which is associated with this permit, signed in accordance with Part VII.H of this permit. 2. An owner or operator may terminate coverage when one or more the following conditions have been met: a. Total project completion - All construction activity identified in the SWPPP has been completed; and all areas of disturbance have achieved final stabilization; and all temporary, structural erosion and sediment control measures have been removed; and all post-construction stormwater management practices have been constructed in conformance with the SWPPP and are operational; (Part V.A.2.b) 30 b. Planned shutdown with partial project completion - All soil disturbance activities have ceased; and all areas disturbed as of the project shutdown date have achieved final stabilization; and all temporary, structural erosion and sediment control measures have been removed; and all post- construction stormwater management practices required for the completed portion of the project have been constructed in conformance with the SWPPP and are operational; c. A new owner or operator has obtained coverage under this permit in accordance with Part II.F. of this permit. d. The owner or operator obtains coverage under an alternative SPDES general permit or an individual SPDES permit. 3. For construction activities meeting subdivision 2a. or 2b. of this Part, the owner or operator shall have the qualified inspector perform a final site inspection prior to submitting the NOT. The qualified inspector shall, by signing the “Final Stabilization” and “Post-Construction Stormwater Management Practice certification statements on the NOT, certify that all the requirements in Part V.A.2.a. or b. of this permit have been achieved. 4. For construction activities that are subject to the requirements of a regulated, traditional land use control MS4 and meet subdivision 2a. or 2b. of this Part, the owner or operator shall have the regulated, traditional land use control MS4 sign the “MS4 Acceptance” statement on the NOT in accordance with the requirements in Part VII.H. of this permit. The regulated, traditional land use control MS4 official, by signing this statement, has determined that it is acceptable for the owner or operator to submit the NOT in accordance with the requirements of this Part. The regulated, traditional land use control MS4 can make this determination by performing a final site inspection themselves or by accepting the qualified inspector’s final site inspection certification(s) required in Part V.A.3. of this permit. 5. For construction activities that require post-construction stormwater management practices and meet subdivision 2a. of this Part, the owner or operator must, prior to submitting the NOT, ensure one of the following: a. the post-construction stormwater management practice(s) and any right-of- way(s) needed to maintain such practice(s) have been deeded to the municipality in which the practice(s) is located, (Part V.A.5.b) 31 b. an executed maintenance agreement is in place with the municipality that will maintain the post-construction stormwater management practice(s), c. for post-construction stormwater management practices that are privately owned, the owner or operator has a mechanism in place that requires operation and maintenance of the practice(s) in accordance with the operation and maintenance plan, such as a deed covenant in the owner or operator’s deed of record, d. for post-construction stormwater management practices that are owned by a public or private institution (e.g. school, university, hospital), government agency or authority, or public utility; the owner or operator has policy and procedures in place that ensures operation and maintenance of the practices in accordance with the operation and maintenance plan. Part VI. REPORTING AND RETENTION RECORDS A. Record Retention The owner or operator shall retain a copy of the NOI, NOI Acknowledgment Letter, SWPPP, MS4 SWPPP Acceptance form and any inspection reports that were prepared in conjunction with this permit for a period of at least five (5) years from the date that the Department receives a complete NOT sub mitted in accordance with Part V. of this general permit. B. Addresses With the exception of the NOI, NOT, and MS4 SWPPP Acceptance form (which must be submitted to the address referenced in Part II.B.1 of this permit), all written correspondence requested by the Department, including individual permit applications, shall be sent to the address of the appropriate DOW Water (SPDES) Program contact at the Regional Office listed in Appendix F. Part VII. STANDARD PERMIT CONDITIONS A. Duty to Comply The owner or operator must comply with all conditions of this permit. All contractors and subcontractors associated with the project must comply with the terms of the SWPPP. Any non-compliance with this permit constitutes a violation of the Clean Water (Part VII.A) 32 Act (CWA) and the ECL and is grounds for an enforcement action against the owner or operator and/or the contractor/subcontractor; permit revocation, suspension or modification; or denial of a permit renewal application. Upon a finding of significant non - compliance with this permit or the applicable SWPPP, the Department may order an immediate stop to all construction activity at the site until the non-compliance is remedied. The stop work order shall be in writing, shall describe the non -compliance in detail, and shall be sent to the owner or operator. If any human remains or archaeological remains are encountered during excavation, the owner or operator must immediately cease, or cause to cease, all construction activity in the area of the remains and notify the appropriate Reg ional Water Engineer (RWE). Construction activity shall not resume until written permission to do so has been received from the RWE. B. Continuation of the Expired General Permit This permit expires five (5) years from the effective date. If a new general permit is not issued prior to the expiration of this general permit, an owner or operator with coverage under this permit may continue to operate and discharge in accordance with the terms and conditions of this general permit, if it is extended pursuant to the State Administrative Procedure Act and 6 NYCRR Part 621, until a new general permit is issued. C. Enforcement Failure of the owner or operator, its contractors, subcontractors, agents and/or assigns to strictly adhere to any of the permit requirements contained herein shall constitute a violation of this permit. There are substantial criminal, civil, and administrative penalties associated with violating the provisions of this permit. Fines of up to $37,500 per day for each violation and imprisonment for up to fifteen (15) years may be assessed depending upon the nature and degree of the offense. D. Need to Halt or Reduce Activity Not a Defense It shall not be a defense for an owner or operator in an enforcement action that it would have been necessary to halt or reduce the construction activity in order to maintain compliance with the conditions of this permit. (Part VII.E) 33 E. Duty to Mitigate The owner or operator and its contractors and subcontractors shall take all reasonable steps to minimize or prevent any discharge in violation of this permit which has a reasonable likelihood of adversely affecting human health or the environment. F. Duty to Provide Information The owner or operator shall furnish to the Department, within a reasonable specified time period of a written request, all documentation necessary to demonstrate eligibility and any information to determine compliance with this permit or to determine whether cause exists for modifying or revoking this permit, or suspending or denying coverage under this permit, in accordance with the terms and conditions of this permit. The NOI, SWPPP and inspection reports required by this permit are public documents that the owner or operator must make available for review and copying by any person within five (5) business days of the owner or operator receiving a written request by any such person to review these documents. Copying of documents will be done at the requester’s expense. G. Other Information When the owner or operator becomes aware that they failed to submit any relevant facts, or submitted incorrect information in the NOI or in any of the documents required by this permit , or have made substantive revisions to the SWPPP (e.g. th e scope of the project changes significantly, the type of post-construction stormwater management practice(s) changes, there is a reduction in the sizing of the post-construction stormwater management practice, or there is an increase in the disturbance ar ea or impervious area), which were not reflected in the original NOI submitted to the Department, they shall promptly submit such facts or information to the Department using the contact information in Part II.A. of this permit. Failure of the owner or operator to correct or supplement any relevant facts within five (5) business days of becoming aware of the deficiency shall constitute a violation of this permit. H. Signatory Requirements 1. All NOIs and NOTs shall be signed as follows: a. For a corporation these forms shall be signed by a responsible corporate officer. For the purpose of this section, a responsible corporate officer means: (Part VII.H.1.a) 34 (i) a president, secretary, treasurer, or vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy or decision-making functions for the corporation; or (ii) the manager of one or more manufacturing, production or operating facilities, provided the manager is authorized to make management decisions which govern the operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiating and directing other comprehensive measures to assure long term environmental compliance with environmental laws and regulations; the manager can ensure that the necessary systems are established or actions taken to gather complete and accurate information for permit application requirements; and where authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures; b. For a partnership or sole proprietorship these forms shall be signed by a general partner or the proprietor, respectively; or c. For a municipality, State, Federal, or other public agency these forms shall be signed by either a principal executive officer or ranking elected official. For purposes of this section, a principal executive officer of a Federal agency includes: (i) the chief executive officer of the agency, or (ii) a senior executive officer having responsibility for the overall operations of a principal geographic unit of the agency (e.g., Regional Administrators of EPA). 2. The SWPPP and other information requested by the Department shall be signed by a person described in Part VII.H.1. of this permit or by a duly authorized representative of that person. A person is a duly authorized representative only if: a. The authorization is made in writing by a person described in Part VII.H.1. of this permit; b. The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility or activity, such as the position of plant manager, operator of a well or a well field, (Part VII.H.2.b) 35 superintendent, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters for the company. (A duly authorized representative may thus be either a named individual or any individual occupying a named position) and, c. The written authorization shall include the name, title and signature of the authorized representative and be attached to the SWPPP. 3. All inspection reports shall be signed by the qualified inspector that performs the inspection. 4. The MS4 SWPPP Acceptance form shall be signed by the principal executive officer or ranking elected official from the regulated, traditional land use control MS4, or by a duly authorized representative of that person. It shall constitute a permit violation if an incorrect and/or improper signatory authorizes any required forms, SWPPP and/or inspection reports. I. Property Rights The issuance of this permit does not convey any property rights of any sort, nor any exclusive privileges, nor does it authorize any injury to private property nor any invasion of personal rights, nor any infringement of Federal, State or local laws or reg ulations. Owners or operators must obtain any applicable conveyances, easements, licenses and/or access to real property prior to commencing construction activity. J. Severability The provisions of this permit are severable, and if any provision of this permit, or the application of any provision of this permit to any circumstance, is held invalid, the application of such provision to other circumstances, and the remainder of this permit shall not be affected thereby. K. Requirement to Obtain Coverage Under an Alternative Permit 1. The Department may require any owner or operator authorized by this permit to apply for and/or obtain either an individual SPDES permit or another SPDES general permit. When the Department requires any discharger authorized by a general permit to apply for an individual SPDES permit, it shall notify the discharger in writing that a permit application is required. This notice shall (Part VII.K.1) 36 include a brief statement of the reasons for this decision, an application form, a statement setting a time frame for the owner or operator to file the application for an individual SPDES permit, and a deadline, not sooner than 180 days from owner or operator receipt of the notification letter, whereby the authorization to discharge under this general permit shall be terminated. Applications must be submitted to the appropriate Permit Administrator at the Regional Office. The Department may grant additional time upon demonstration, to the satisfaction of the Department, that additional time to apply for an alternative authorization is necessary or where the Department has not provided a permit determination in accordance with Part 621 of this Title. 2. When an individual SPDES permit is issued to a discharger authorized to discharge under a general SPDES permit for the same discharge(s), the general permit authorization for outfalls authorized under the individual SPDES permit is automatically terminated on the effective date of the individual permit unless termination is earlier in accordance with 6 NYCRR Part 750. L. Proper Operation and Maintenance The owner or operator shall at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) which are installed or used by the owner or operator to achieve compliance with the conditions of this permit and with the requirements of the SW PPP. M. Inspection and Entry The owner or operator shall allow an authorized representative of the Department, EPA, applicable county health department, or, in the case of a construction site which discharges through an MS4, an authorized representative of the MS4 receiving the discharge, upon the presentation of credentials and other documents as may be required by law, to: 1. Enter upon the owner’s or operator's premises where a regulated facility or activity is located or conducted or where records must be k ept under the conditions of this permit; 2. Have access to and copy at reasonable times, any records that must be kept under the conditions of this permit; and (Part VII.M.3) 37 3. Inspect at reasonable times any facilities or equipment (including monitoring and control equipment), practices or operations regulated or required by this permit. 4. Sample or monitor at reasonable times, for purposes of assuring permit compliance or as otherwise authorized by the Act or ECL, any substances or parameters at any location. N. Permit Actions This permit may, at any time, be modified, suspended, revoked, or renewed by the Department in accordance with 6 NYCRR Part 621. The filing of a request by the owner or operator for a permit modification, revocation and reissuance, termination, a notification of planned changes or anticipated noncompliance does not limit, diminish and/or stay compliance with any terms of this permit. O. Definitions Definitions of key terms are included in Appendix A of this permit. P. Re-Opener Clause 1. If there is evidence indicating potential or realized impacts on water quality due to any stormwater discharge associated with construction activity covered by this permit, the owner or operator of such discharge may be required to obtain an individual permit or alternative general permit in accordance with Part VII.K. of this permit or the permit may be modified to include different limitations and/or requirements. 2. Any Department initiated permit modification, suspension or revocation will be conducted in accordance with 6 NYCRR Part 621, 6 NYCRR 750 -1.18, and 6 NYCRR 750-1.20. Q. Penalties for Falsification of Forms and Reports In accordance with 6NYCRR Part 750-2.4 and 750-2.5, any person who knowingly makes any false material statement, representation, or certification in any application, record, report or other document filed or required to be maintained under this permit, including reports of compliance or noncompliance shall, upon conviction, be punished in accordance with ECL §71-1933 and or Articles 175 and 210 of the New York State Penal Law. (Part VII.R) 38 R. Other Permits Nothing in this permit relieves the owner or operator from a requirement to obtain any other permits required by law. 39 APPENDIX A – Acronyms and Definitions Acronyms APO – Agency Preservation Officer BMP – Best Management Practice CPESC – Certified Professional in Erosion and Sediment Control Cpv – Channel Protection Volume CWA – Clean Water Act (or the Federal Water Pollution Control Act, 33 U.S.C. §1251 et seq) DOW – Division of Water EAF – Environmental Assessment Form ECL - Environmental Conservation Law EPA – U. S. Environmental Protection Agency HSG – Hydrologic Soil Group MS4 – Municipal Separate Storm Sewer System NOI – Notice of Intent NOT – Notice of Termination NPDES – National Pollutant Discharge Elimination System OPRHP – Office of Parks, Recreation and Historic Places Qf – Extreme Flood Qp – Overbank Flood RRv – Runoff Reduction Volume RWE – Regional Water Engineer SEQR – State Environmental Quality Review SEQRA - State Environmental Quality Review Act SHPA – State Historic Preservation Act SPDES – State Pollutant Discharge Elimination System SWPPP – Stormwater Pollution Prevention Plan TMDL – Total Maximum Daily Load UPA – Uniform Procedures Act USDA – United States Department of Agriculture WQv – Water Quality Volume Appendix A 40 Definitions All definitions in this section are solely for the purposes of this permit. Agricultural Building – a structure designed and constructed to house farm implements, hay, grain, poultry, livestock or other horticultural products; excluding any structure designed, constructed or used, in whole or in part, for human habitation, as a place of employment where agricultural products are processed, treated or packaged, or as a place used by the public. Agricultural Property –means the land for construction of a barn, agricultural building, silo, stockyard, pen or other structural practices identified in Table II in the “Agricultural Management Practices Catalog for Nonpoint Source Pollution in New York State” prepared by the Department in cooperation with agencies of New York Nonpoint Source Coordinating Committee (dated June 2007). Alter Hydrology from Pre to Post-Development Conditions - means the post- development peak flow rate(s) has increased by more than 5% of the pre-developed condition for the design storm of interest (e.g. 10 yr and 100 yr). Combined Sewer - means a sewer that is designed to collect and convey both “sewage” and “stormwater”. Commence (Commencement of) Construction Activities - means the initial disturbance of soils associated with clearing, grading or excavation activit ies; or other construction related activities that disturb or expose soils such as demolition, stockpiling of fill material, and the initial installation of erosion and sediment control practices required in the SWPPP. See definition for “Construction Activity(ies)” also. Construction Activity(ies) - means any clearing, grading, excavation, filling, demolition or stockpiling activities that result in soil disturbance. Clearing activities can include, but are not limited to, logging equipment operation, the cutting and skidding of trees, stump removal and/or brush root removal. Construction activity does not include routine maintenance that is performed to maintain the original line and grade, hydraulic capacity, or original purpose of a facility. Construction Site – means the land area where construction activity(ies) will occur. See definition for “Commence (Commencement of) Construction Activities” and “Larger Common Plan of Development or Sale” also. Dewatering – means the act of draining rainwater and/or groundwater from building foundations, vaults or excavations/trenches. Direct Discharge (to a specific surface waterbody) - means that runoff flows from a construction site by overland flow and the first point of discharge is the specific surface waterbody, or runoff flows from a construction site to a separate storm sewer system Appendix A 41 and the first point of discharge from the separate storm sewer system is the specific surface waterbody. Discharge(s) - means any addition of any pollutant to waters of the State through an outlet or point source. Embankment –means an earthen or rock slope that supports a road/highway. Endangered or Threatened Species – see 6 NYCRR Part 182 of the Department’s rules and regulations for definition of terms and requirements. Environmental Conservation Law (ECL) - means chapter 43-B of the Consolidated Laws of the State of New York, entitled the Environmental Conservation Law. Equivalent (Equivalence) – means that the practice or measure meets all the performance, longevity, maintenance, and safety objectives of the technical standard and will provide an equal or greater degree of water quality protection. Final Stabilization - means that all soil disturbance activities have ceased and a uniform, perennial vegetative cover with a density of eighty (80) percent over the entire pervious surface has been established; or other equivalent stabilization measures, such as permanent landscape mulches, rock rip-rap or washed/crushed stone have been applied on all disturbed areas that are not covered by permanent structures, concrete or pavement. General SPDES permit - means a SPDES permit issued pursuant to 6 NYCRR Part 750-1.21 and Section 70-0117 of the ECL authorizing a category of discharges. Groundwater(s) - means waters in the saturated zone. The saturated zone is a subsurface zone in which all the interstices are filled with water under pressure greater than that of the atmosphere. Although the zone may contain gas-filled interstices or interstices filled with fluids other than water, it is still considered saturated. Historic Property – means any building, structure, site, object or district that is listed on the State or National Registers of Historic Places or is determined to be eligible for listing on the State or National Registers of Historic Places. Impervious Area (Cover) - means all impermeable surfaces that cannot effectively infiltrate rainfall. This includes paved, concrete and gravel surfaces (i.e. parking lots, driveways, roads, runways and sidewalks); building rooftops and miscellaneous impermeable structures such as patios, pools, and sheds. Infeasible – means not technologically possible, or not economically practicable and achievable in light of best industry practices. Appendix A 42 Larger Common Plan of Development or Sale - means a contiguous area where multiple separate and distinct construction activities are occurring, or will occur, under one plan. The term “plan” in “larger common plan of development or sale” is broadly defined as any announcement or piece of documentation (including a sign, public notice or hearing, marketing plan, advertisement, drawing, permit application, State Environmental Quality Review Act (SEQRA) environmental assessment form or other documents, zoning request, computer design, etc.) or physical demarcation (including boundary signs, lot stakes, surveyor markings, etc.) indicating that construction activities may occur on a specific plot. For discrete construction projects that are located within a larger common plan of development or sale that are at least 1/4 mile apart, each project can be treated as a separate plan of development or sale provided any interconnecting road, pipeline or utility project that is part of the same “common plan” is not concurrently being disturbed. Minimize – means reduce and/or eliminate to the extent achievable using control measures (including best management practices) that are technologically available and economically practicable and achievable in light of best industry practices. Municipal Separate Storm Sewer (MS4) - a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains): (i) Owned or operated by a State, city, town, borough, county, parish, district, association, or other public body (created by or pursuant to State law) having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under State law such as a sewer district, flood control district or drainage district, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the CWA that discharges to surface waters of the State; (ii) Designed or used for collecting or conveying stormwater; (iii) Which is not a combined sewer; and (iv) Which is not part of a Publicly Owned Treatment Works (POTW) as defined at 40 CFR 122.2. National Pollutant Discharge Elimination System (NPDES) - means the national system for the issuance of wastewater and stormwater permits under the Federal Water Pollution Control Act (Clean Water Act). Natural Buffer –means an undisturbed area with natural cover running along a surface water (e.g. wetland, stream, river, lake, etc.). New Development – means any land disturbance that does not meet the definition of Redevelopment Activity included in this appendix. Appendix A 43 New York State Erosion and Sediment Control Certificate Program – a certificate program that establishes and maintains a process to identify and recognize individuals who are capable of developing, designing, inspecting and maintaining erosion and sediment control plans on projects that disturb soils in New York State. The certificate program is administered by the New York State Conservation District Employees Association. NOI Acknowledgment Letter - means the letter that the Department sends to an owner or operator to acknowledge the Department’s receipt and acceptance of a complete Notice of Intent. This letter documents the owner’s or operator’s authorization to discharge in accordance with the general permit for stormwater discharges from construction activity. Nonpoint Source - means any source of water pollution or pollutants which is not a discrete conveyance or point source permitted pursuant to Title 7 or 8 of Article 17 of the Environmental Conservation Law (see ECL Section 17-1403). Overbank –means flow events that exceed the capacity of the stream channel and spill out into the adjacent floodplain. Owner or Operator - means the person, persons or legal entity which owns or leases the property on which the construction activity is occurring; an entity that has operational control over the construction plans and specifications, including the ability to make modifications to the plans and specifications; and/or an entity that has day-to-day operational control of those activities at a project that are necessary to ensure compliance with the permit conditions. Performance Criteria – means the design criteria listed under the “Required Elements” sections in Chapters 5, 6 and 10 of the technical standard, New York State Stormwater Management Design Manual, dated January 2015. It does not include the Sizing Criteria (i.e. WQv, RRv, Cpv, Qp and Qf ) in Part I.C.2. of the permit. Point Source - means any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, vessel or other floating craft, or landfill leachate collection system from which pollutants are or may be discharged. Pollutant - means dredged spoil, filter backwash, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand and industrial, municipal, agricultural waste and ballast discharged into water; which may cause or might reasonably be expected to cause pollution of the waters of the state in contravention of the standards or guidance values adopted as provided in 6 NYCRR Parts 700 et seq . Appendix A 44 Qualified Inspector - means a person that is knowledgeable in the principles and practices of erosion and sediment control, such as a licensed Professional Engineer, Certified Professional in Erosion and Sediment Control (CPESC), Registered Landscape Architect, New York State Erosion and Sediment Control Certificate Program holder or other Department endorsed individual(s). It can also mean someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided that person has training in the principles and practices of erosion and sediment control. Training in the principles and practices of erosion and sediment control means that the individual working under the direct supervision of the licensed Professional Engineer or Registered Landscape Architect has received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department en dorsed entity. After receiving the initial training, the individual working under the direct supervision of the licensed Professional Engineer or Registered Landscape Architect shall receive four (4) hours of training every three (3) years. It can also mean a person that meets the Qualified Professional qualifications in addition to the Qualified Inspector qualifications. Note: Inspections of any post-construction stormwater management practices that include structural components, such as a dam for an impoundment, shall be performed by a licensed Professional Engineer. Qualified Professional - means a person that is knowledgeable in the principles and practices of stormwater management and treatment, such as a licensed Professional Engineer, Registered Landscape Architect or other Department endorsed individual(s). Individuals preparing SWPPPs that require the post-construction stormwater management practice component must have an understanding of the principles of hydrology, water quality management practice design, water quantity control design, and, in many cases, the principles of hydraulics. All components of the SWPPP that involve the practice of engineering, as defined by the NYS Education Law (see Article 145), shall be prepared by, or under the direct supervision of, a professional engineer licensed to practice in the State of New York. Redevelopment Activity(ies) – means the disturbance and reconstruction of existing impervious area, including impervious areas that were removed from a project site within five (5) years of preliminary project plan submission to the local government (i.e. site plan, subdivision, etc.). Regulated, Traditional Land Use Control MS4 - means a city, town or village with land use control authority that is authorized to discharge under New York State DEC’s Appendix A 45 SPDES General Permit For Stormwater Discharges from Municipal Separate Stormwater Sewer Systems (MS4s) or the City of New York’s Individual SPDES Permit for their Municipal Separate Storm Sewer Systems (NY-0287890). Routine Maintenance Activity - means construction activity that is performed to maintain the original line and grade, hydraulic capacity, or original purpose of a facility, including, but not limited to: ▪ Re-grading of gravel roads or parking lots, ▪ Cleaning and shaping of existing roadside ditches and culverts that maintains the approximate original line and grade, and hydraulic capacity of the ditch, ▪ Cleaning and shaping of existing roadside ditches that does not maintain the approximate original grade, hydraulic capacity and purpose of the ditch if the changes to the line and grade, hydraulic capacity or purpose of the ditch are installed to improve water quality and quantity controls (e.g. installing grass lined ditch), ▪ Placement of aggregate shoulder backing that stabilizes the transition between the road shoulder and the ditch or embankment, ▪ Full depth milling and filling of existing asphalt pavements, replacement of concrete pavement slabs, and similar work that does not expose soil or disturb the bottom six (6) inches of subbase material, ▪ Long-term use of equipment storage areas at or near highway maintenance facilities, ▪ Removal of sediment from the edge of the highway to restore a previously existing sheet-flow drainage connection from the highway surface to the highway ditch or embankment, ▪ Existing use of Canal Corp owned upland disposal sites for the canal, and ▪ Replacement of curbs, gutters, sidewalks and guide rail posts. Site limitations – means site conditions that prevent the use of an infiltration technique and or infiltration of the total WQv. Typical site limitations include: seasonal high groundwater, shallow depth to bedrock, and soils with an infiltration rate less than 0.5 inches/hour. The existence of site limitations shall be confirmed and documented using actual field testing (i.e. test pits, soil borings, and infiltration test) or using information from the most current United States Department of Agriculture (USDA) Soil Survey for the County where the project is located. Sizing Criteria – means the criteria included in Part I.C.2 of the permit that are used to size post-construction stormwater management control practices. The criteria include; Water Quality Volume (WQv), Runoff Reduction Volume (RRv), Channel Protection Volume (Cpv), Overbank Flood (Qp), and Extreme Flood (Qf). State Pollutant Discharge Elimination System (SPDES) - means the system established pursuant to Article 17 of the ECL and 6 NYCRR Part 750 for issuance of permits authorizing discharges to the waters of the state. Appendix A 46 Steep Slope – means land area designated on the current United States Department of Agriculture (“USDA”) Soil Survey as Soil Slope Phase “D”, (provided the map unit name is inclusive of slopes greater than 25%) , or Soil Slope Phase E or F, (regardless of the map unit name), or a combination of the three designations. Streambank – as used in this permit, means the terrain alongside the bed of a creek or stream. The bank consists of the sides of the channel, between which the flow is confined. Stormwater Pollution Prevention Plan (SWPPP) – means a project specific report, including construction drawings, that among other things: describes the construction activity(ies), identifies the potential sources of pollution at the construction site; describes and shows the stormwater controls that will be used to control the pollutants (i.e. erosion and sediment controls; for many projects, includes post-construction stormwater management controls); and identifies procedures the owner or operator will implement to comply with the terms and conditions of the permit. See Part III of the permit for a complete description of the information that must be included in the SWPPP. Surface Waters of the State - shall be construed to include lakes, bays, sounds, ponds, impounding reservoirs, springs, rivers, streams, creeks, estuaries, marshes, inlets, canals, the Atlantic ocean within the territorial seas of the state of New York and all other bodies of surface water, natural or artificial, inland or coastal, fresh or salt, public or private (except those private waters that do not combine or effect a junction with natural surface waters), which are wholly or partially within or bordering the state or within its jurisdiction. Waters of the state are further defined in 6 NYCRR Parts 800 to 941. Temporarily Ceased – means that an existing disturbed area will not be disturbed again within 14 calendar days of the previous soil disturbance. Temporary Stabilization - means that exposed soil has been covered with material(s) as set forth in the technical standard, New York Standards and Specifications for Erosion and Sediment Control, to prevent the exposed soil from eroding. The materials can include, but are not limited to, mulch, seed and mulch, and erosion control mats (e.g. jute twisted yarn, excelsior wood fiber mats). Total Maximum Daily Loads (TMDLs) - A TMDL is the sum of the allowable loads of a single pollutant from all contributing point and nonpoint sources. It is a calculation of the maximum amount of a pollutant that a waterbody can receive on a daily basis and still meet water quality standards, and an allocation of that amount to the pollutant's sources. A TMDL stipulates wasteload allocations (WLAs) for point source discharges, load allocations (LAs) for nonpoint sources, and a margin of safety (MOS). Trained Contractor - means an employee from the contracting (construction) company, identified in Part III.A.6., that has received four (4) hours of Department endorsed Appendix A 47 training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity. After receiving the initial training, the trained contractor shall receive four (4) hours of training every three (3) years. It can also mean an employee from the contracting (construction) company, identified in Part III.A.6., that meets the qualified inspector qualifications (e.g. licensed Professional Engineer, Certified Professional in Erosion and Sediment Control (CPESC), Registered Landscape Architect, New York State Erosion and Sediment Control Certificate Program holder, or someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided they have received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity). The trained contractor is responsible for the day to day implementation of the SWPPP. Uniform Procedures Act (UPA) Permit - means a permit required under 6 NYCRR Part 621 of the Environmental Conservation Law (ECL), Article 70. Water Quality Standard - means such measures of purity or quality for any waters in relation to their reasonable and necessary use as promulgated in 6 NYCRR Part 700 et seq. 48 APPENDIX B – Required SWPPP Components by Project Type Table 1 Construction Activities that Require the Preparation of a SWPPP That Only Includes Erosion and Sediment Controls The following construction activities that involve soil disturbances of one (1) or more acres of land, but less than five (5) acres: • Single family home not located in one of the watersheds listed in Appendix C or not directly discharging to one of the 303(d) segments listed in Appendix E • Single family residential subdivisions with 25% or less impervious cover at total site build-out and not located in one of the watersheds listed in Appendix C and not directly discharging to one of the 303(d) segments listed in Appendix E • Construction of a barn or other agricultural building, silo, stock yard or pen. The following construction activities that involve soil disturbances between five thousand (5000) square feet and one (1) acre of land: All construction activities located in the watersheds identified in Appendix D that involve soil disturbances between five thousand (5,000) square feet and one (1) acre of land. The following construction activities that involve soil disturbances of one (1) or more acres of land: • Installation of underground, linear utilities; such as gas lines, fiber -optic cable, cable TV, electric, telephone, sewer mains, and water mains • Environmental enhancement projects, such as wetland mitigation projects, stormwater retrofits and stream restoration projects • Pond construction • Linear bike paths running through areas with vegetative cover, including bike paths surfaced with an impervious cover • Cross-country ski trails and walking/hiking trails • Sidewalk, bike path or walking path projects, surfaced with an impervious cover, that are not part of residential, commercial or institutional development; • Sidewalk, bike path or walking path projects, surfaced with an impervious cover, that include incidental shoulder or curb work along an existing highway to support construction of the sidewalk, bike path or walking path. • Slope stabilization projects • Slope flattening that changes the grade of the site, but does not significantly change the runoff characteristics Appendix B 49 Table 1 (Continued) CONSTRUCTION ACTIVITIES THAT REQUIRE THE PREPARATION OF A SWPPP THAT ONLY INCLUDES EROSION AND SEDIMENT CONTROLS The following construction activities that involve soil disturbances of one (1) or more acres of land: • Spoil areas that will be covered with vegetation • Vegetated open space projects (i.e. recreational parks, lawns, meadows, fields, downhill ski trails) excluding projects that alter hydrology from pre to post development conditions, • Athletic fields (natural grass) that do not include the construction or reconstruction of impervious area and do not alter hydrology from pre to post development conditions • Demolition project where vegetation will be established, and no redevelopment is planned • Overhead electric transmission line project that does not include the construction of permanent access roads or parking areas surfaced with impervious cover • Structural practices as identified in Table II in the “Agricultural Management Practices Catalog f or Nonpoint Source Pollution in New York State”, excluding projects that involve soil disturbances of greater than five acres and construction activities that include the construction or reconstruction of impervious area • Temporary access roads, median crossovers, detour roads, lanes, or other temporary impervious areas that will be restored to pre-construction conditions once the construction activit y is complete Appendix B 50 Table 2 CONSTRUCTION ACTIVITIES THAT REQUIRE THE PREPARATION OF A SWPPP THAT INCLUDES POST-CONSTRUCTION STORMWATER MANAGEMENT PRACTICES The following construction activities that involve soil disturbances of one (1) or more acres of land: • Single family home located in one of the watersheds listed in Appendix C or directly discharging to one of the 303(d) segments listed in Appendix E • Single family home that disturbs five (5) or more acres of land • Single family residential subdivisions located in one of the watersheds listed in Appendix C or directly discharging to one of the 303(d) segments listed in Appendix E • Single family residential subdivisions that involve soil disturbances of between one (1) and five (5) acres of land with greater than 25% impervious cover at total site build-out • Single family residential subdivisions that involve soil disturbances of five (5) or more acres of land, and single family residential subdivisions that involve soil disturbances of less than five (5) acres that are part of a larger common plan of development or sale that will ultimately disturb five or more acres of land • Multi-family residential developments; includes duplexes, townhomes, condominiums, senior housing complexes, apartment complexes, and mobile home parks • Airports • Amusement parks • Breweries, cideries, and wineries, including establishments constructed on agricultural land • Campgrounds • Cemeteries that include the construction or reconstruction of impervious area (>5% of disturbed area) or alter the hydrology from pre to post development conditions • Commercial developments • Churches and other places of worship • Construction of a barn or other agricultural building (e.g. silo) and structural practices as identified in Table II in the “Agricultural Management Practices Catalog for Nonpoint Source Pollution in New York State” that include the construction or reconstruction of impervious area, excluding projects that involve soil disturbances of less than five acres. • Golf courses • Institutional development; includes hospitals, prisons, schools and colleges • Industrial facilities; includes industrial parks • Landfills • Municipal facilities; includes highway garages, transfer stations, office buildings, POTW’s, water treatment plants, and water storage tanks • Office complexes • Playgrounds that include the construction or reconstruction of impervious area • Sports complexes • Racetracks; includes racetracks with earthen (dirt) surface • Road construction or reconstruction, including roads constructed as part of the construction activities listed in Table 1 Appendix B 51 Table 2 (Continued) CONSTRUCTION ACTIVITIES THAT REQUIRE THE PREPARATION OF A SWPPP THAT INCLUDES POST-CONSTRUCTION STORMWATER MANAGEMENT PRACTICES The following construction activities that involve soil disturbances of one (1) or more acres of land: • Parking lot construction or reconstruction, including parking lots constructed as part of the construction activities listed in Table 1 • Athletic fields (natural grass) that include the construction or reconstruction of impervious area (>5% of disturbed area) or alter the hydrology from pre to post development conditions • Athletic fields with artificial turf • Permanent access roads, parking areas, substations, compressor stations and well drilling pads, surfaced with impervious cover, and constructed as part of an over-head electric transmission line project, wind-power project, cell tower project, oil or gas well drilling project, sewer or water main project or other linear utility project • Sidewalk, bike path or walking path projects, surfaced with an impervious cover, that are part of a residential, commercial or institutional development • Sidewalk, bike path or walking path projects, surfaced with an impervious cover, that are part of a highway construction or reconstruction project • All other construction activities that include the construction or reconstruction of impervious area or alter the hydrology from pre to post development conditions, and are not listed in Table 1 52 APPENDIX C – Watersheds Requiring Enhanced Phosphorus Removal Watersheds where owners or operators of construction activities identified in Table 2 of Appendix B must prepare a SWPPP that includes post-construction stormwater management practices designed in conformance with the Enhanced Phosphorus Removal Standards included in the technical standard, New York State Stormwater Management Design Manual (“Design Manual”). • Entire New York City Watershed located east of the Hudson River - Figure 1 • Onondaga Lake Watershed - Figure 2 • Greenwood Lake Watershed -Figure 3 • Oscawana Lake Watershed – Figure 4 • Kinderhook Lake Watershed – Figure 5 Appendix C 53 Figure 1 - New York City Watershed East of the Hudson Appendix C 54 Figure 2 - Onondaga Lake Watershed Appendix C 55 Figure 3 - Greenwood Lake Watershed Appendix C 56 Figure 4 - Oscawana Lake Watershed Appendix C 57 Figure 5 - Kinderhook Lake Watershed 58 APPENDIX D – Watersheds with Lower Disturbance Threshold Watersheds where owners or operators of construction activities that involve soil disturbances between five thousand (5000) square feet and one (1) acre of land must obtain coverage under this permit. Entire New York City Watershed that is located east of the Hudson River - See Figure 1 in Appendix C 59 APPENDIX E – 303(d) Segments Impaired by Construction Related Pollutant(s) List of 303(d) segments impaired by pollutants related to construction activity (e.g. silt, sediment or nutrients). The list was developed using ”The Final New York State 2016 Section 303(d) List of Impaired Waters Requiring a TMDL/Other Strategy” dated November 2016. Owners or operators of single family home and single family residential subdivisions with 25% or less total impervious cover at total site build-out that involve soil disturbances of one or more acres of land, but less than 5 acres, and directly discharge to one of the listed segments below shall prepare a SWPPP that includes post-construction stormwater management practices designed in conformance with the New York State Stormwater Management Design Manual (“Design Manual”), dated January 2015. COUNTY WATERBODY POLLUTANT Albany Ann Lee (Shakers) Pond, Stump Pond Nutrients Albany Basic Creek Reservoir Nutrients Allegany Amity Lake, Saunders Pond Nutrients Bronx Long Island Sound, Bronx Nutrients Bronx Van Cortlandt Lake Nutrients Broome Fly Pond, Deer Lake, Sky Lake Nutrients Broome Minor Tribs to Lower Susquehanna (north) Nutrients Broome Whitney Point Lake/Reservoir Nutrients Cattaraugus Allegheny River/Reservoir Nutrients Cattaraugus Beaver (Alma) Lake Nutrients Cattaraugus Case Lake Nutrients Cattaraugus Linlyco/Club Pond Nutrients Cayuga Duck Lake Nutrients Cayuga Little Sodus Bay Nutrients Chautauqua Bear Lake Nutrients Chautauqua Chadakoin River and tribs Nutrients Chautauqua Chautauqua Lake, North Nutrients Chautauqua Chautauqua Lake, South Nutrients Chautauqua Findley Lake Nutrients Chautauqua Hulburt/Clymer Pond Nutrients Clinton Great Chazy River, Lower, Main Stem Silt/Sediment Clinton Lake Champlain, Main Lake, Middle Nutrients Clinton Lake Champlain, Main Lake, North Nutrients Columbia Kinderhook Lake Nutrients Columbia Robinson Pond Nutrients Cortland Dean Pond Nutrients 303(d) Segments Impaired by Construction Related Pollutant(s) 60 Dutchess Fall Kill and tribs Nutrients Dutchess Hillside Lake Nutrients Dutchess Wappingers Lake Nutrients Dutchess Wappingers Lake Silt/Sediment Erie Beeman Creek and tribs Nutrients Erie Ellicott Creek, Lower, and tribs Silt/Sediment Erie Ellicott Creek, Lower, and tribs Nutrients Erie Green Lake Nutrients Erie Little Sister Creek, Lower, and tribs Nutrients Erie Murder Creek, Lower, and tribs Nutrients Erie Rush Creek and tribs Nutrients Erie Scajaquada Creek, Lower, and tribs Nutrients Erie Scajaquada Creek, Middle, and tribs Nutrients Erie Scajaquada Creek, Upper, and tribs Nutrients Erie South Branch Smoke Cr, Lower, and tribs Silt/Sediment Erie South Branch Smoke Cr, Lower, and tribs Nutrients Essex Lake Champlain, Main Lake, South Nutrients Essex Lake Champlain, South Lake Nutrients Essex Willsboro Bay Nutrients Genesee Bigelow Creek and tribs Nutrients Genesee Black Creek, Middle, and minor tribs Nutrients Genesee Black Creek, Upper, and minor tribs Nutrients Genesee Bowen Brook and tribs Nutrients Genesee LeRoy Reservoir Nutrients Genesee Oak Orchard Cr, Upper, and tribs Nutrients Genesee Tonawanda Creek, Middle, Main Stem Nutrients Greene Schoharie Reservoir Silt/Sediment Greene Sleepy Hollow Lake Silt/Sediment Herkimer Steele Creek tribs Silt/Sediment Herkimer Steele Creek tribs Nutrients Jefferson Moon Lake Nutrients Kings Hendrix Creek Nutrients Kings Prospect Park Lake Nutrients Lewis Mill Creek/South Branch, and tribs Nutrients Livingston Christie Creek and tribs Nutrients Livingston Conesus Lake Nutrients Livingston Mill Creek and minor tribs Silt/Sediment Monroe Black Creek, Lower, and minor tribs Nutrients Monroe Buck Pond Nutrients Monroe Cranberry Pond Nutrients 303(d) Segments Impaired by Construction Related Pollutant(s) 61 Monroe Lake Ontario Shoreline, Western Nutrients Monroe Long Pond Nutrients Monroe Mill Creek and tribs Nutrients Monroe Mill Creek/Blue Pond Outlet and tribs Nutrients Monroe Minor Tribs to Irondequoit Bay Nutrients Monroe Rochester Embayment - East Nutrients Monroe Rochester Embayment - West Nutrients Monroe Shipbuilders Creek and tribs Nutrients Monroe Thomas Creek/White Brook and tribs Nutrients Nassau Beaver Lake Nutrients Nassau Camaans Pond Nutrients Nassau East Meadow Brook, Upper, and tribs Silt/Sediment Nassau East Rockaway Channel Nutrients Nassau Grant Park Pond Nutrients Nassau Hempstead Bay Nutrients Nassau Hempstead Lake Nutrients Nassau Hewlett Bay Nutrients Nassau Hog Island Channel Nutrients Nassau Long Island Sound, Nassau County Waters Nutrients Nassau Massapequa Creek and tribs Nutrients Nassau Milburn/Parsonage Creeks, Upp, and tribs Nutrients Nassau Reynolds Channel, west Nutrients Nassau Tidal Tribs to Hempstead Bay Nutrients Nassau Tribs (fresh) to East Bay Nutrients Nassau Tribs (fresh) to East Bay Silt/Sediment Nassau Tribs to Smith/Halls Ponds Nutrients Nassau Woodmere Channel Nutrients New York Harlem Meer Nutrients New York The Lake in Central Park Nutrients Niagara Bergholtz Creek and tribs Nutrients Niagara Hyde Park Lake Nutrients Niagara Lake Ontario Shoreline, Western Nutrients Niagara Lake Ontario Shoreline, Western Nutrients Oneida Ballou, Nail Creeks and tribs Nutrients Onondaga Harbor Brook, Lower, and tribs Nutrients Onondaga Ley Creek and tribs Nutrients Onondaga Minor Tribs to Onondaga Lake Nutrients Onondaga Ninemile Creek, Lower, and tribs Nutrients Onondaga Onondaga Creek, Lower, and tribs Nutrients Onondaga Onondaga Creek, Middle, and tribs Nutrients 303(d) Segments Impaired by Construction Related Pollutant(s) 62 Onondaga Onondaga Lake, northern end Nutrients Onondaga Onondaga Lake, southern end Nutrients Ontario Great Brook and minor tribs Silt/Sediment Ontario Great Brook and minor tribs Nutrients Ontario Hemlock Lake Outlet and minor tribs Nutrients Ontario Honeoye Lake Nutrients Orange Greenwood Lake Nutrients Orange Monhagen Brook and tribs Nutrients Orange Orange Lake Nutrients Orleans Lake Ontario Shoreline, Western Nutrients Orleans Lake Ontario Shoreline, Western Nutrients Oswego Lake Neatahwanta Nutrients Oswego Pleasant Lake Nutrients Putnam Bog Brook Reservoir Nutrients Putnam Boyd Corners Reservoir Nutrients Putnam Croton Falls Reservoir Nutrients Putnam Diverting Reservoir Nutrients Putnam East Branch Reservoir Nutrients Putnam Lake Carmel Nutrients Putnam Middle Branch Reservoir Nutrients Putnam Oscawana Lake Nutrients Putnam Palmer Lake Nutrients Putnam West Branch Reservoir Nutrients Queens Bergen Basin Nutrients Queens Flushing Creek/Bay Nutrients Queens Jamaica Bay, Eastern, and tribs (Queens) Nutrients Queens Kissena Lake Nutrients Queens Meadow Lake Nutrients Queens Willow Lake Nutrients Rensselaer Nassau Lake Nutrients Rensselaer Snyders Lake Nutrients Richmond Grasmere Lake/Bradys Pond Nutrients Rockland Congers Lake, Swartout Lake Nutrients Rockland Rockland Lake Nutrients Saratoga Ballston Lake Nutrients Saratoga Dwaas Kill and tribs Silt/Sediment Saratoga Dwaas Kill and tribs Nutrients Saratoga Lake Lonely Nutrients Saratoga Round Lake Nutrients Saratoga Tribs to Lake Lonely Nutrients 303(d) Segments Impaired by Construction Related Pollutant(s) 63 Schenectady Collins Lake Nutrients Schenectady Duane Lake Nutrients Schenectady Mariaville Lake Nutrients Schoharie Engleville Pond Nutrients Schoharie Summit Lake Nutrients Seneca Reeder Creek and tribs Nutrients St.Lawrence Black Lake Outlet/Black Lake Nutrients St.Lawrence Fish Creek and minor tribs Nutrients Steuben Smith Pond Nutrients Suffolk Agawam Lake Nutrients Suffolk Big/Little Fresh Ponds Nutrients Suffolk Canaan Lake Silt/Sediment Suffolk Canaan Lake Nutrients Suffolk Flanders Bay, West/Lower Sawmill Creek Nutrients Suffolk Fresh Pond Nutrients Suffolk Great South Bay, East Nutrients Suffolk Great South Bay, Middle Nutrients Suffolk Great South Bay, West Nutrients Suffolk Lake Ronkonkoma Nutrients Suffolk Long Island Sound, Suffolk County, West Nutrients Suffolk Mattituck (Marratooka) Pond Nutrients Suffolk Meetinghouse/Terrys Creeks and tribs Nutrients Suffolk Mill and Seven Ponds Nutrients Suffolk Millers Pond Nutrients Suffolk Moriches Bay, East Nutrients Suffolk Moriches Bay, West Nutrients Suffolk Peconic River, Lower, and tidal tribs Nutrients Suffolk Quantuck Bay Nutrients Suffolk Shinnecock Bay and Inlet Nutrients Suffolk Tidal tribs to West Moriches Bay Nutrients Sullivan Bodine, Montgomery Lakes Nutrients Sullivan Davies Lake Nutrients Sullivan Evens Lake Nutrients Sullivan Pleasure Lake Nutrients Tompkins Cayuga Lake, Southern End Nutrients Tompkins Cayuga Lake, Southern End Silt/Sediment Tompkins Owasco Inlet, Upper, and tribs Nutrients Ulster Ashokan Reservoir Silt/Sediment Ulster Esopus Creek, Upper, and minor tribs Silt/Sediment Warren Hague Brook and tribs Silt/Sediment 303(d) Segments Impaired by Construction Related Pollutant(s) 64 Warren Huddle/Finkle Brooks and tribs Silt/Sediment Warren Indian Brook and tribs Silt/Sediment Warren Lake George Silt/Sediment Warren Tribs to L.George, Village of L George Silt/Sediment Washington Cossayuna Lake Nutrients Washington Lake Champlain, South Bay Nutrients Washington Tribs to L.George, East Shore Silt/Sediment Washington Wood Cr/Champlain Canal and minor tribs Nutrients Wayne Port Bay Nutrients Westchester Amawalk Reservoir Nutrients Westchester Blind Brook, Upper, and tribs Silt/Sediment Westchester Cross River Reservoir Nutrients Westchester Lake Katonah Nutrients Westchester Lake Lincolndale Nutrients Westchester Lake Meahagh Nutrients Westchester Lake Mohegan Nutrients Westchester Lake Shenorock Nutrients Westchester Long Island Sound, Westchester (East) Nutrients Westchester Mamaroneck River, Lower Silt/Sediment Westchester Mamaroneck River, Upper, and minor tribs Silt/Sediment Westchester Muscoot/Upper New Croton Reservoir Nutrients Westchester New Croton Reservoir Nutrients Westchester Peach Lake Nutrients Westchester Reservoir No.1 (Lake Isle) Nutrients Westchester Saw Mill River, Lower, and tribs Nutrients Westchester Saw Mill River, Middle, and tribs Nutrients Westchester Sheldrake River and tribs Silt/Sediment Westchester Sheldrake River and tribs Nutrients Westchester Silver Lake Nutrients Westchester Teatown Lake Nutrients Westchester Titicus Reservoir Nutrients Westchester Truesdale Lake Nutrients Westchester Wallace Pond Nutrients Wyoming Java Lake Nutrients Wyoming Silver Lake Nutrients 65 APPENDIX F – List of NYS DEC Regional Offices Region COVERING THE FOLLOWING COUNTIES: DIVISION OF ENVIRONMENTAL PERMITS (DEP) PERMIT ADMINISTRATORS DIVISION OF WATER (DOW) WATER (SPDES) PROGRAM 1 NASSAU AND SUFFOLK 50 CIRCLE ROAD STONY BROOK, NY 11790 TEL. (631) 444-0365 50 CIRCLE ROAD STONY BROOK, NY 11790-3409 TEL. (631) 444-0405 2 BRONX, KINGS, NEW YORK, QUEENS AND RICHMOND 1 HUNTERS POINT PLAZA, 47-40 21ST ST. LONG ISLAND CITY, NY 11101-5407 TEL. (718) 482-4997 1 HUNTERS POINT PLAZA, 47-40 21ST ST. LONG ISLAND CITY, NY 11101-5407 TEL. (718) 482-4933 3 DUTCHESS, ORANGE, PUTNAM, ROCKLAND, SULLIVAN, ULSTER AND WESTCHESTER 21 SOUTH PUTT CORNERS ROAD NEW PALTZ, NY 12561-1696 TEL. (845) 256-3059 100 HILLSIDE AVENUE, SUITE 1W WHITE PLAINS, NY 10603 TEL. (914) 428 - 2505 4 ALBANY, COLUMBIA, DELAWARE, GREENE, MONTGOMERY, OTSEGO, RENSSELAER, SCHENECTADY AND SCHOHARIE 1150 NORTH WESTCOTT ROAD SCHENECTADY, NY 12306-2014 TEL. (518) 357-2069 1130 NORTH WESTCOTT ROAD SCHENECTADY, NY 12306-2014 TEL. (518) 357-2045 5 CLINTON, ESSEX, FRANKLIN, FULTON, HAMILTON, SARATOGA, WARREN AND WASHINGTON 1115 STATE ROUTE 86, PO BOX 296 RAY BROOK, NY 12977-0296 TEL. (518) 897-1234 232 GOLF COURSE ROAD WARRENSBURG, NY 12885-1172 TEL. (518) 623-1200 6 HERKIMER, JEFFERSON, LEWIS, ONEIDA AND ST. LAWRENCE STATE OFFICE BUILDING 317 WASHINGTON STREET WATERTOWN, NY 13601-3787 TEL. (315) 785-2245 STATE OFFICE BUILDING 207 GENESEE STREET UTICA, NY 13501-2885 TEL. (315) 793-2554 7 BROOME, CAYUGA, CHENANGO, CORTLAND, MADISON, ONONDAGA, OSWEGO, TIOGA AND TOMPKINS 615 ERIE BLVD. WEST SYRACUSE, NY 13204-2400 TEL. (315) 426-7438 615 ERIE BLVD. WEST SYRACUSE, NY 13204-2400 TEL. (315) 426-7500 8 CHEMUNG, GENESEE, LIVINGSTON, MONROE, ONTARIO, ORLEANS, SCHUYLER, SENECA, STEUBEN, WAYNE AND YATES 6274 EAST AVON-LIMA ROADAVON, NY 14414-9519 TEL. (585) 226-2466 6274 EAST AVON-LIMA RD. AVON, NY 14414-9519 TEL. (585) 226-2466 9 ALLEGANY, CATTARAUGUS, CHAUTAUQUA, ERIE, NIAGARA AND WYOMING 270 MICHIGAN AVENUE BUFFALO, NY 14203-2999 TEL. (716) 851-7165 270 MICHIGAN AVENUE BUFFALO, NY 14203-2999 TEL. (716) 851-7070 STATE POLLUTANT DISCHARGE ELIMINATION SYSTEM FOR CONSTRUCTION ACTIVITIES CONSTRUCTION SITE LOG BOOK TABLE OF CONTENTS 1. Pre-Construction Meeting Documents 2. Operator’s Certification 3. Pre-Construction Site Assessment Form 4. Construction Duration Inspections i. Directions ii. Monthly Summary Report iii. Modification to the SWPPP 5. Three-Month Status Reports 6. Final Stabilization and Retention of Records i. Qualified Professional’s Certification of Final Stabilization ii. Retention of Records 1. PRE-CONSTRUCTION MEETING DOCUMENTS Project Name _________________________________________________________________ GP-0-08-001 Permit No.________________________ Date of Authorization______________ Name of Operator _____________________________________________________________ General Contractor ____________________________________________________________ The Following Information To Be Read By All Person.s Involved in The Construction of Stormwater Related Activities: Site Assessment and Inspections – a. The Operator agrees to have a qualified professional1 conduct an assessment of the site prior to the commencement of construction and certify in this inspection report that the appropriate erosion and sediment controls described in the SWPPP have been adequately installed or implemented to ensure overall preparedness of the site for the commencement of construction. Following the commencement of construction, site inspections shall be conducted by the qualified professional at least every 14 calendar days and within 24 hours of the end of a storm event of 0.5 inches or greater. b. The Operator shall maintain a record of all inspection reports in this site log book. The site log book shall be maintained on site and be made available to the permitting authorities upon request. Prior to the commencement of construction2, the Operator shall certify in the site log book that the SWPPP, prepared in accordance with the State’s standards and meets all Federal, State and local erosion and sediment control requirements. The Operator shall post at the site, in a publicly-accessible location, a summary of the site inspection activities on a monthly basis. c. Prior to filing of the Notice of Termination or the end of permit term, the Operator shall have the qualified professional perform a final site inspection. The qualified professional shall certify that the site has undergone final stabilization3 using either vegetative or structural stabilization methods and that all temporary erosion and sediment controls (such as silt fencing) not needed for long-term erosion control have been removed. 1 “Qualified Professional means a person knowledgeable in the principles and practice of erosion and sediment controls, such as a Certified Professional in Erosion and Sediment Control (CPESC), soil scientist, licensed engineer or someone working under the direction and supervision of a licensed engineer (person must have experience in the principles and practices of erosion and sediment control). Certified Professional in Erosion and Sediment Control (CPESC), or soil scientist. 2 “Commencement of construction” means the initial removal of vegetation and disturbance of soils associated with clearing, grading or excavating activities or other construction activities. 3 “Final stabilization” means that all soil-disturbing activities at the site have been completed and a uniform, perennial vegetative cover with a density of eighty (80) percent has been established or equivalent stabilization measures (such as the use of mulches or geotextiles) have been employed on all unpaved areas and areas not covered by permanent structures. 2. OPERATOR’S CERTIFICATION "I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. Further, I hereby certify that the SWPPP meets all Federal State and local erosion and sediment control requirements. I am aware that false statements made herein are punishable as a class A misdemeanor pursuant to Section 210.45 of the Penal Law. " Name (please print) Title: _______________________________________________________________________ Date: _______________________________________________________________________ Address: ________________________________________________________________ Phone: _______________________________________________________________________ Email: _______________________________________________________________________ 3. PRE-CONSTRUCTION SITE ASSESSMENT FORM _________________________________________ __________________________________ Inspector (print name) Date of Inspection ________________________________________ _________________________________ Qualified Professional (print name) Qualified Professional Signature The above signed acknowledges that, to the best of his/her knowledge, all information provided on the following forms is accurate and complete. NOTE: Provide comments below as necessary a. Notice of Intent, SWPPP, and Contractors. Certification: Y N NA [ ] [ ] [ ] Has a Notice of Intent been filed with the NYS Department of Conservation? [ ] [ ] [ ] Is the SWPPP on-site? Where?______________________________ [ ] [ ] [ ] Is the Plan current? What is the latest revision date?______________ [ ] [ ] [ ] Have all contractors involved with implementing the erosion and sediment control portions of the SWPPP signed the contractor’s certification? b. Resource Protection Y N NA [ ] [ ] [ ] Are construction limits clearly flagged or fenced? [ ] [ ] [ ] Important trees and associated rooting zones, on-site septic systems absorption fields, existing vegetated areas suitable for filter strips, especially in perimeter areas, etc. have been flagged for protection. [ ] [ ] [ ] Creek crossings installed prior to land-disturbing activity, including clearing and blasting. c. Surface Water Protection Y N NA [ ] [ ] [ ] Clean stormwater runoff has been diverted from areas to be disturbed. [ ] [ ] [ ] Bodies of water located either on site or in the vicinity of the site have been identified and protected. [ ] [ ] [ ] Appropriate practices to protect on-site or downstream surface water are installed. d. Stabilized Construction Entrance Y N NA [ ] [ ] [ ] A temporary construction entrance to capture mud and debris from construction vehicles before they enter the public highway has been installed. [ ] [ ] [ ] Other access areas (entrances, construction routes, equipment parking areas) are stabilized immediately as work takes place with gravel or other cover. [ ] [ ] [ ] Sediment tracked onto public streets is removed or cleaned on a regular basis. e. Perimeter Sediment Controls Y N NA [ ] [ ] [ ] Silt fence material and installation comply with the standard drawing and specifications. [ ] [ ] [ ] Silt fences are installed at appropriate spacing intervals [ ] [ ] [ ] Sediment/detention basin was installed as first land disturbing activity. [ ] [ ] [ ] Sediment traps and barriers are installed. 4. CONSTRUCTION DURATION INSPECTIONS These Inspection Forms will be filled out during the entire construction phase of the project. _________________________________________ __________________________________ Inspector (print name) Date of Inspection __________________________________________ __________________________________ Qualified Professional (print name) Qualified Professional Signature The above signed acknowledges that, to the best of his/her knowledge, all information provided on the forms is accurate and complete. Check one of the following: Weekly Inspection or, Rain Event Inspection (greater than 0.5 inches in 24 hour period) □ Weekly Inspection or, □ Rain Event Inspection (greater than 0.5 inches in 24 hrs) Date of Rain Event __________ Amount of Rain ____ in. On a plan/sketch below that represents the project area, or on an attached site map: 1.Indicate the extent of all disturbed site areas and drainage pathways; 2.Indicate site areas that are expected to undergo initial disturbance or significant site work within the next 14-day period; 3.Indicate all areas of the site that have undergone temporary or permanent stabilization; 4.Indicate all disturbed site areas that have not undergone active site work during the previous 14-day period; SITE PLAN/SKETCH Time on site __________ AM/PM Time off site __________ AM/PM Weather __________ Temp __________ °F Photos Taken _______ Comments: Contractor Signature __________________________________ Date _____________ General Housekeeping Y N NA [ ] [ ] [ ] Is there an increase in turbidity that will cause a substantial visible contrast to natural conditions? [ ] [ ] [ ] Is there residue from oil and floating substances, visible oil film, or globules or grease? [ ] [ ] [ ] Are facilities and equipment necessary for implementation of erosion and sediment control in working order and/or properly maintained? [ ] [ ] [ ] Is construction impacting the adjacent property? [ ] [ ] [ ] Is dust adequately controlled? Temporary Stream Crossing Y N NA [ ] [ ] [ ] Maximum diameter pipes necessary to span creek without dredging are installed. [ ] [ ] [ ] Installed non-woven geotextile fabric beneath approaches. [ ] [ ] [ ] 20 feet minimum approach length, minimum 6 inch depth of rock, 18 inch maximum fill depth over pipes. [ ] [ ] [ ] Installed diversion dike/swale through both approaches 50 feet (max) from top of bank. [ ] [ ] [ ] Fill composed of clean shot rock or KTC Class III channel lining. [ ] [ ] [ ] Rock clean enough to remove mud from vehicles & prevent sediment from entering stream during high flow. Excavation Dewatering Y N NA [ ] [ ] [ ] Upstream and downstream berms (sandbags, inflatable dams, etc.) are installed per plan. [ ] [ ] [ ] Clean water from upstream pool is being pumped to the downstream pool. [ ] [ ] [ ] Sediment laden water from work area is being discharged to a silt-trapping device. [ ] [ ] [ ] Constructed upstream berm with one-foot minimum freeboard. Vegetative Filter Strips Y N NA [ ] [ ] [ ] Vegetation is dense and there are no signs of erosion. [ ] [ ] [ ] Width of filter strip is per the approved plan. [ ] [ ] [ ] Ground slope of filter strip is between 1% and 5%. Level Spreader Y N NA [ ] [ ] [ ] Installed per plan. [ ] [ ] [ ] Constructed on undisturbed soil, not on fill, receiving only clear, non-sediment laden flow. [ ] [ ] [ ] Flow sheets out of level spreader without erosion on downstream edge. Interceptor Dikes and Swales Y N NA [ ] [ ] [ ] Installed per plan with minimum side slopes 2H:1V or flatter. [ ] [ ] [ ] Stabilized by geotextile fabric, seed, or mulch with no erosion occurring. [ ] [ ] [ ] Sediment-laden runoff directed to sediment trapping structure Sediment Control Y N NA [ ] [ ] [ ] Sediment control practices are located and installed correctly. [ ] [ ] [ ] BMPs are maintained per specifications [ ] [ ] [ ] Stockpiles are stabilized and contained. [ ] [ ] [ ] De-watering operations prevent direct discharges to sensitive features. [ ] [ ] [ ] Construction Schedule—Are clearing and grading operations divided into stages for large areas (i.e. greater than 2 acres), as opposed to mass grading? (NOTE: If staged, erosion control measures may also need to be staged.) Adverse Impacts or Off-Site Degradation Y N NA [ ] [ ] [ ] Work is within the limits of the approved plans, including clearing and blasting. [ ] [ ] [ ] Adverse impacts – ponds, streams, wetlands and sinkholes are free of sediment from site. [ ] [ ] [ ] Off-site degradation - sediment is kept out of roadways, adjacent property, storm sewers, or air (dust). Stabilized Construction Entrance Y N NA [ ] [ ] [ ] Stone is clean enough to effectively remove mud from vehicles. [ ] [ ] [ ] Installed per standards and specifications? [ ] [ ] [ ] Does all traffic use the stabilized entrance to enter and leave site? [ ] [ ] [ ] Is adequate drainage provided to prevent ponding at entrance? Reinforced Silt Fence Y N NA [ ] [ ] [ ] Installed on Contour, 10 feet from toe of slope (not across conveyance channels). [ ] [ ] [ ] Joints constructed by wrapping the two ends together for continuous support. [ ] [ ] [ ] Installed steel posts, downstream side of flow, maximum 6 foot intervals with 6 x 6 inch 14 gage wire. [ ] [ ] [ ] Fabric buried 6 inches minimum. [ ] [ ] [ ] Posts are stable, fabric is tight and without rips or frayed areas. [ ] [ ] [ ] Sediment accumulation is ___% of design capacity. Stone Check Dam Y N NA [ ] [ ] [ ] Channel is without erosion (i.e., flow is not eroding soil underneath or around the structure). [ ] [ ] [ ] Check is in good condition (i.e., rocks have not been displaced and no permanent pools behind the structure). [ ] [ ] [ ] Sediment accumulation is ___% of design capacity. Block and Gravel Drop Inlet Protection Y N NA [ ] [ ] [ ] Installed concrete blocks lengthwise so open ends face outward, not upward. [ ] [ ] [ ] Placed wire screen between No. 3 crushed stone and concrete blocks. [ ] [ ] [ ] Sediment accumulation ___% of design capacity. Filter Fabric (Drop) Inlet Protection Y N NA [ ] [ ] [ ] Installed 2-inch x 4-inch wood frame and wood posts, with maximum 3-foot spacing. [ ] [ ] [ ] Filter fabric buried a minimum of 8 inches and secured to frame/posts with staples at max 8-inch spacing. [ ] [ ] [ ] Posts 3-foot maximum spacing between posts. [ ] [ ] [ ] Posts are stable, fabric is tight and without rips or frayed areas. [ ] [ ] [ ] Sediment accumulation is ___% of design capacity. Excavated Drop Inlet Protection Y N NA [ ] [ ] [ ] Excavated depth is a minimum 1-foot, but no more that 2-feet maximum. [ ] [ ] [ ] Gravel supported by hardware cloth to allow drainage and restrict sediment movement. [ ] [ ] [ ] Excavated side slopes should be 2:1. Temporary Sediment Trap Y N NA [ ] [ ] [ ] Outlet structure is constructed per the approved plan or drawing. [ ] [ ] [ ] Geotextile fabric has been placed beneath rock fill. [ ] [ ] [ ] Sediment accumulation is ___% of design capacity. Temporary Sediment Basin Y N NA [ ] [ ] [ ] Basin and outlet structure constructed per the approved plan. [ ] [ ] [ ] Basin side slopes are stabilized with seed/mulch. [ ] [ ] [ ] Sediment accumulation is ___% of design capacity [ ] [ ] [ ] Drainage structure flushed and basin surface restored upon removal of sediment basin facility. Page 1 of 3 New York State Department of Environmental Conservation Division of Water 625 Broadway, 4th Floor Albany, New York 12233-3505 *(NOTE: Submit completed form to address above)* NOTICE OF TERMINATION for Storm Water Discharges Authorized under the SPDES General Permit for Construction Activity Please indicate your permit identification number: NYR ___ ___ ___ ___ ___ ___ I. Owner or Operator Information 1. Owner/Operator Name: 2. Street Address: 3. City/State/Zip: 4. Contact Person: 4a.Telephone: 5. Contact Person E-Mail: II. Project Site Information 5. Project/Site Name: 6. Street Address: 7. City/Zip: 8. County: III. Reason for Termination 9a. G All disturbed areas have achieved final stabilization in accordance with the general permit and SWPPP. *Date final stabilization completed (month/year): 9b. G Permit coverage has been transferred to new owner/operator. Indicate new owner/operator’s permit identification number: NYR ___ ___ ___ ___ ___ ___ (Note: Permit coverage can not be terminated by owner identified in I.1. above until new owner/operator obtains coverage under the general permit) 9c. G Other (Explain on Page 2) IV. Final Site Information: 10a. Did this construction activity require the development of a SWPPP that includes post-construction stormwater management practices? G yes G no ( If no, go to question 10f.) 10b. Have all post-construction stormwater management practices included in the final SWPPP been constructed? G yes G no (If no, explain on Page 2) 10c. Identify the entity responsible for long-term operation and maintenance of practice(s)? Page 2 of 3 NOTICE OF TERMINATION for Storm Water Discharges Authorized under the SPDES General Permit for Construction Activity - continued 10d. Has the entity responsible for long-term operation and maintenance been given a copy of the operation and maintenance plan required by the general permit? G yes G no 10e. Indicate the method used to ensure long-term operation and maintenance of the post-construction stormwater management practice(s): G Post-construction stormwater management practice(s) and any right-of-way(s) needed to maintain practice(s) have been deeded to the municipality. G Executed maintenance agreement is in place with the municipality that will maintain the post-construction stormwater management practice(s). G For post-construction stormwater management practices that are privately owned, the deed of record has been modified to include a deed covenant that requires operation and maintenance of the practice(s) in accordance with the operation and maintenance plan. G For post-construction stormwater management practices that are owned by a public or private institution (e.g. school, college, university), or government agency or authority, policy and procedures are in place that ensures operation and maintenance of the practice(s) in accordance with the operation and maintenance plan. 10f. Provide the total area of impervious surface (i.e. roof, pavement, concrete, gravel, etc.) constructed within the disturbance area? (acres) 11. Is this project subject to the requirements of a regulated, traditional land use control MS4? G yes G no (If Yes, complete section VI - “MS4 Acceptance” statement V. Additional Information/Explanation: (Use this section to answer questions 9c. and 10b., if applicable) VI. MS4 Acceptance - MS4 Official (principal executive officer or ranking elected official) or Duly Authorized Representative (Note: Not required when 9b. is checked -transfer of coverage) I have determined that it is acceptable for the owner or operator of the construction project identified in question 5 to submit the Notice of Termination at this time. Printed Name: Title/Position: Signature: Date: Page 3 of 3 NOTICE OF TERMINATION for Storm Water Discharges Authorized under the SPDES General Permit for Construction Activity - continued VII. Qualified Inspector Certification - Final Stabilization: I hereby certify that all disturbed areas have achieved final stabilization as defined in the current version of the general permit, and that all temporary, structural erosion and sediment control measures have been removed. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of the referenced permit and the laws of the State of New York and could subject me to criminal, civil and/or administrative proceedings. Printed Name: Title/Position: Signature: Date: VIII. Qualified Inspector Certification - Post-construction Stormwater Management Practice(s): I hereby certify that all post-construction stormwater management practices have been constructed in conformance with the SWPPP. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of the referenced permit and the laws of the State of New York and could subject me to criminal, civil and/or administrative proceedings. Printed Name: Title/Position: Signature: Date: IX. Owner or Operator Certification I hereby certify that this document was prepared by me or under my direction or supervision. My determination, based upon my inquiry of the person(s) who managed the construction activity, or those persons directly responsible for gathering the information, is that the information provided in this document is true, accurate and complete. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of the referenced permit and the laws of the State of New York and could subject me to criminal, civil and/or administrative proceedings. Printed Name: Title/Position: Signature: Date: (NYS DEC Notice of Termination - January 2010) KATHY HOCHUL Governor RANDY SIMONS Commissioner Pro Tempore July 01, 2024 James Easton Project Engineer EP Land Services 621 Columbia Street Cohoes, NY 12047 Re: USACE Station Park Subdivision NYS Route 29, City of Saratoga Springs, Saratoga County, NY 23PR07392 Dear James Easton: Thank you for requesting the comments of the State Historic Preservation Office (SHPO). We have reviewed the project in accordance with Section 106 of the National Historic Preservation Act of 1966. These comments are those of the SHPO and relate only to Historic/Cultural resources. They do not include potential environmental impacts to New York State Parkland that may be involved in or near your project. Based upon this review, it is the opinion of the New York SHPO that no historic properties, including archaeological and/or historic resources, will be affected by this undertaking. If further correspondence is required regarding this project, please be sure to refer to the OPRHP Project Review (PR) number noted above. If you have any questions, please contact Leslie Krupa at the following email address: Leslie.Krupa@parks.ny.gov Sincerely, R. Daniel Mackay Deputy State Historic Preservation Officer Division for Historic Preservation New York State Office of Parks, Recreation and Historic Preservation Division for Historic Preservation, Peebles Island, PO Box 189, Waterford, New York 12188-0189 (518) 237-8643 • https://parks.ny.gov/shpo New York State Office of Parks, Recreation and Historic Preservation Division for Historic Preservation, Peebles Island, PO Box 189, Waterford, New York 12188-0189 (518) 237-8643 • https://parks.ny.gov/shpo KATHY HOCHUL ERIK KULLESEID Governor Commissioner September 5, 2023 James Easton Project Engineer EP Land Services 621 Columbia Street Cohoes, NY 12047 Re: DEC Station Park Subdivision City of Saratoga Springs, Saratoga County, NY 23PR07392 Dear James Easton: Thank you for requesting the comments of the Division for Historic Preservation of the Office of Parks, Recreation and Historic Preservation (OPRHP). We have reviewed the submitted materials in accordance with the New York State Historic Preservation Act of 1980 (section 14.09 of the New York Parks, Recreation and Historic Preservation Law). These comments are those of the Division for Historic Preservation and relate only to Historic/Cultural resources. They do not include potential environmental impacts to New York State Parkland that may be involved in or near your project. Such impacts must be considered as part of the environmental review of the project pursuant to the State Environmental Quality Review Act (New York Environmental Conservation Law Article 8) and its implementing regulations (6NYCRR Part 617). OPRHP has reviewed the Phase I Archaeological Survey Report prepared for this project (October 2017; 23SR00470). No archaeological sites were identified by the survey. Therefore, it is the opinion of the OPRHP that no properties, including archaeological and/or historic resources, listed in or eligible for the New York State and National Registers of Historic Places will be impacted by this project. If you have any questions, I can be reached at Jessica.Schreyer@parks.ny.gov. Sincerely, Jessica Schreyer Historic Preservation Program Analyst - Archaeologist Prepared by: EP Land Services LLC 621 Columbia Street Ext. Cohoes, NY 12047 (518) 785-9000 Post Construction Maintenance Manual For (Part III) Station Park Subdivision City of Saratoga Springs Saratoga County, New York July 12, 2024 Post Construction Maintenance Manual July 2024 POST CONSTRUCTION STORMWATER MAINTENANCE MANUAL for STATION PARK SUBDIVISION CITY OF SARATOGA SPRINGS, SARATOGA COUNTY Table of Contents 1.0 OPERATION AND MAINTENANCE INFORMATION ...................................................................... 1 Site Address ........................................................................................................................................................ 1 Descriptive Site Location ..................................................................................................................................... 1 Property Owner ................................................................................................................................................... 1 Property Management ......................................................................................................................................... 1 2.0 DESIGN AND CONSTRUCTION INFORMATION ............................................................................ 2 Maintenance Mechanism .................................................................................................................................... 2 Required Inspections .......................................................................................................................................... 2 Providers of Maintenance Services .................................................................................................................... 2 Emergency Contact ............................................................................................................................................. 2 3.0 MAINTENANCE AND INSPECTION RESPONSIBILITIES .............................................................. 3 Permitting Authority ............................................................................................................................................. 3 Design Engineer .................................................................................................................................................. 3 Contractor ............................................................................................................................................................ 3 Emergency Contact ............................................................................................................................................. 3 4.0 FUNDING MECHANISM .................................................................................................................. 4 Estimated Annual O & M Costs........................................................................................................................... 4 5.0 POST-CONSTRUCTION STORMWATER MANAGEMENT FACILITIES (PRACTICES) ................. 5 Practice A: Wet Swale (O-2) .............................................................................................................................. 5 Practice B: Underground Infiltration Array (I-4) .............................................................................................. 6 Practice C: Underground Basins (I-2) .............................................................................................................. 7 Practice D: Hydrodynamic Unit (Contech)- Pretreatment .............................................................................. 8 Practice E: Private Closed Drainage System .................................................................................................. 9 6.0 ATTACHMENTS TO MAINTENANCE PLAN ................................................................................. 10 Exhibits ............................................................................................................................................................. 11 Exhibit G – Post Construction Maintenance Information ............................................................................ 12 .1 Location Map .................................................................................................................................... 12 .2 Maintenance Checklist ...................................................................................................................... 12 .3 Hydrodynamic Maintenance Checklist.............................................................................................. 12 .4 Estimated O & M Costs..................................................................................................................... 12 i:\engineering projects\prime companies\2022\2022-02-saratoga station\03-admin\reports\storm report\post construction maintenance plan\pcmp.doc Post Construction Maintenance Manual July 2024 Page 1 1.0 OPERATION AND MAINTENANCE INFORMATION Site Address NYS Route 29 Descriptive Site Location Property located on between NYS Route 29 and Station Lane Property Owner Prime Companies 621 Columbia Street Ext. Cohoes NY 12047 Property Management (if different than Owner) SAME AS OWNER Post Construction Maintenance Manual July 2024 Page 2 2.0 DESIGN AND CONSTRUCTION INFORMATION Maintenance Mechanism Maintenance Agreement Commercial Property Homeowners Association Maintenance Assumed by Government Entity List: Required Inspections · Inspection by a licensed professional engineer is required in accordance with Inspection forms in Exhibit G. · Local municipality has authority to enter the site to inspect the stormwater management practices. The frequency of municipal inspection has not been determined. Providers of Maintenance Services Coordinator of maintenance activities and inspections: Prime Companies Landscaping and snow removal activities: TO BE DETERMINED___________________________________(List Company) Stormwater Management Practice (SMP) Maintenance: TO BE DETERMINED___________________________________(List Company) SMP inspections and party required to submit required reports to the local municipality: TO BE DETERMINED____________________________________(List Company) Emergency Contact (Local government authority to contact in case of failure of the stormwater treatment practice that threatens public safety) Saratoga Springs, Public Works 474 Broadway Saratoga Springs NY 12866 Phone: (518) 587-3500 ext. 2555 If calling off-hours for an emergency, please call the Saratoga Springs Police Office at 518-584-1800 Post Construction Maintenance Manual July 2024 Page 3 3.0 MAINTENANCE AND INSPECTION RESPONSIBILITIES Permitting Authority City of Saratoga Springs 474 Broadway Saratoga Springs NY 12866 Phone: (518) 587-3550 Design Engineer EP Land Services LLC 621 Columbia Street Ext. Cohoes, NY 12047 Phone: 518-785-9000 Contractor TO BE DETERMINED _________________________________________________(List Company) Emergency Contact (Local government authority to contact in case of failure of the stormwater treatment practice that threatens public safety) Saratoga Springs, Public Works 474 Broadway Saratoga Springs NY 12866 Phone: (518) 587-3500 ext. 2555 If calling off-hours for an emergency, please call the Saratoga Springs Police Office at 518-584-1800 Post Construction Maintenance Manual July 2024 Page 4 4.0 FUNDING MECHANISM Maintenance performed by Municipality and Funded through: General Revenues Stormwater Utility of other fee assessment --- OR --- Maintenance performed by Owner and Funded or guaranteed through: Performance Bond Letter of Credit Escrow Account Private Funds Maintenance Agreement, See Attached Estimated Annual O & M Costs The estimated cost of maintenance of the stormwater management practice (SMP) excluding landscaping costs are: $ 13,100 per year. The estimated annual cost is in terms of year 2024 dollars. The anticipated annual cost for subsequent years may be estimated from the attached inflation worksheet. An inflation rate of 3.0% per year has been used. A cost projection is attached that includes a detailed estimate of the annual routine maintenance cost and the cost of infrequent maintenance items. Post Construction Maintenance Manual July 2024 Page 5 5.0 POST-CONSTRUCTION STORMWATER MANAGEMENT FACILITIES (PRACTICES) Practice A: Wet Swale (O-2) Site Map identifying location of practice Refer to Construction Plans Practice Type Wet Swale (O-2) Contributing Drainage Area Post Area #1A Attachments · See Exhibit G.1 for location of Practice A. · See Exhibit G.2 for Operation and Maintenance for required inspections of Infiltration. All or any item(s) indicated on inspection report shall be rectified within one (1) month of report submission. Frequency · Exhibit G.2 shall be completed at least once a year by a certified inspector. Special Needs or Requirements · Testing of sediment must be performed per NYSDEC to determine levels of toxic elements with the soil before sediment within the stilling and infiltration basin is removed and properly disposed of. Post Construction Maintenance Manual July 2024 Page 6 Practice B: Underground Infiltration Array (I-4) Site Map identifying location of practice Refer to Construction Plans Practice Type Infiltration Array #1 and #2 (I-4) Contributing Drainage Area Post Area #2 Attachments · See Exhibit G.1 for location of Practice B. · See Exhibit G.2 for Operation and Maintenance for required inspections of Infiltration. All or any item(s) indicated on inspection report shall be rectified within one (1) month of report submission. Frequency · Exhibit G.2 shall be completed at least once a by a certified inspector. · Sediment in infiltration area shall be removed when 10% of their volume has been occupied. Estimated at every 10-years. Special Needs or Requirements · Testing of sediment must be performed per NYSDEC to determine levels of toxic elements with the soil before sediment within the stilling and infiltration basin is removed and properly disposed of. · Vacuum Truck for sediment removal. · Inspectors and maintenance staff may need to be certified in confined space entry. Post Construction Maintenance Manual July 2024 Page 7 Practice C: Underground Basins (I-2) Site Map identifying location of practice Refer to Construction Plans Practice Type Infiltration Basins (I-2) Contributing Drainage Area Post Area #3A Attachments · See Exhibit G.1 for location of Practice C. · See Exhibit G.2 for Operation and Maintenance for required inspections of Infiltration. All or any item(s) indicated on inspection report shall be rectified within one (1) month of report submission. Frequency · Exhibit G.2 shall be completed least once a year by a certified inspector. · Sediment in infiltration area shall be removed when 10% of their volume has been occupied. Estimated at every 10-years. Special Needs or Requirements · Testing of sediment must be performed per NYSDEC to determine levels of toxic elements with the soil before sediment within the stilling and infiltration basin is removed and properly disposed of. Post Construction Maintenance Manual July 2024 Page 8 Practice D: Hydrodynamic Unit (Contech)- Pretreatment Site Map identifying location of practice Refer to Construction Plans Practice Type Pre-fabricated hydrodynamic unit Contributing Drainage Area Post Area #1A, Post Area #2 and Post Area #3A Attachments · See Exhibit G.1 for location of Practices D. · See Exhibit G.3 for Contech Maintenance Literature for required activities, timing, methods and inspection. Frequency · Exhibit G.3 shall be completed least once a year by a certified inspector. · Sediment removal shall be performed per the Contech Operation and Maintenance manual dictates. Special Needs or Requirements · Testing of sediment must be performed per NYSDEC to determine levels of toxic elements with the soil before sediment within the stilling and infiltration basin is removed and properly disposed of. · Vacuum Truck for sediment removal. · Inspectors and maintenance staff may need to be certified in confined space entry. Post Construction Maintenance Manual July 2024 Page 9 Practice E: Private Closed Drainage System Site Map identifying location of practice Refer to Construction Plans Practice Type N/A Contributing Drainage Area Post Area #1A, Post Area #2, and Post Area #3A Private Drainage System Location Throughout project site – see construction drawings Attachments None Frequency · Private Closed drainage system and catch basins shall be cleaned when maximum 6” sediment occurs within the closed drainage system. Estimated at every 10-years. · Private Catch basin, manholes, outlet structure, flared end sections and piping shall be repaired, replaced or fixed. · Private Closed drainage system and catch basins shall be cleaned when a maximum 6” sediment occurs within the closed drainage system. Estimated at every 10-years. Special Needs or Requirements · High Pressure Water to clean underground closed drainage system. · A vacuum truck may be needed for removal of sediment to wash out location. · Catch basins/ manhole frame and grates, mortar or pipe. Post Construction Maintenance Manual July 2024 Page 10 6.0 ATTACHMENTS TO MAINTENANCE PLAN The following items shall be kept with the Post-Construction Maintenance Plan: Present Item Description As-Built Plans Final Landscaping Plans Refer to Construction Drawings Design Calculations Report Owner shall keep a copy of the Stormwater Management Report, including design calculations, with the Maintenance Plan. Specifications for Potential Repair Items No detailed specifications have been developed for this project. Owner is referred to construction drawing set. Operation, Maintenance and Inspection Checklist Attached document(s) list the estimated frequencies for maintenance and inspection items anticipated with this development project. The checklist is presented as an estimated frequency for activities. Actual site conditions may require more (or less) frequent assessment and maintenance. Manuals and Warranties Any documentation or instructions for proprietary products and mechanical components, such as valves, pumps, aerators, etc. Bid Specifications Detailed bid specifications have not been developed for this project. Owner is referred to construction drawing set. Easements Owner shall keep a copy of all recorded stormwater related easements with the Maintenance Plan. Covenants Not Applicable. Owner shall keep a copy of all stormwater related covenants with the Maintenance Plan. Typically developed for projects with Homeowners Associations. Maintenance Agreement Owner shall keep a copy of the stormwater related Maintenance Agreement with the Maintenance Plan. See attached Agreement between Municipality and Owner regarding upkeep of Stormwater Management Practice. Detailed Cost Estimate Detailed cost estimates are provided, showing anticipated costs for routine and infrequent maintenance aspects related to the Stormwater management practice. Maintenance and Tracking Log Owner shall keep copies of all maintenance, inspection and regulatory correspondence related to the stormwater practice. Correspondence and records shall be made available to regulatory agencies upon request. Post Construction Maintenance Manual July 2024 Page 11 Exhibits Post Construction Maintenance Manual July 2024 Page 12 Exhibit G – Post Construction Maintenance Information .1 Location Map .2 Maintenance Checklist .3 Hydrodynamic Maintenance Checklist .4 Estimated O & M Costs STATION LANE NYS ROUTE 29X ■■ST STST ■■HOTEL4 STORIES110 ROOMSWITH 17 COVERED PARKING STALLSROW HOUSE #7ROW HOUSE #8ROW HOUSE #9ROW HOUSE #10ROW HOUSE #11ROW HOUSE #12ROW HOUSE #13ROW HOUSE #14ROW HOUSE #15ROW HOUSE #16 ROW HOUSE #17 ROW HOUSE #18 ROW HOUSE #41 ROW HOUSE #42 ROW HOUSE #43 ROW HOUSE #44 ROW HOUSE #45 ROW HOUSE #46 ROW HOUSE #35 ROW HOUSE #36 ROW HOUSE #37 ROW HOUSE #38 ROW HOUSE #39 ROW HOUSE #40 ROW HOUSE #31 ROW HOUSE #32 ROW HOUSE #33 ROW HOUSE #34 STSTSTSTSTSTROW HOUSE #1ROW HOUSE #2ROW HOUSE #3ROW HOUSE #4ROW HOUSE #5ROW HOUSE #6 ROW HOUSE #19 ROW HOUSE #20 ROW HOUSE #21 ROW HOUSE #22 ROW HOUSE #23 ROW HOUSE #24BLDG #1MULTIFAMILY4 STORIES184 UNITS162 UNDERGROUND PARKING STALLSBLDG #2MULTIFAMILY4 STORIES160 UNITS165 UNDERGROUND PARKING STALLS2 STORY MAINTENANCE BLDG.100'x20'STATION PARK AVESTATION PARK AVERAILROAD AVE (PRIVATE ROAD)■■■■STSTSTSTSTSTSTSTSTSTST ■■■■■■■■■■MAINT.BLDG./COVEREDPATIO67'x32'ST ■■■■■■■■ ■■■ROW HOUSE #25 ROW HOUSE #26 ROW HOUSE #27 ROW HOUSE #28 ROW HOUSE #29 ROW HOUSE #30■■■STSTSTSTSTSTSTSTSTSTST STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTST■■■■■■■■■■■■■SEALDATENo.DESCRIPTIONSUBMITTAL / REVISIONSPROJ. MANAGER:CHIEF DESIGNER:BYDESIGNED BY:DRAWN BY:DATE:PROJ. No.:SCALE:File Name: I:\Engineering Projects\Prime Companies\2022\2022-02-Saratoga Station\04-Cad File\Stormwater.dwg (Layout: POST MAIN )Date: Mon, Jul 15, 2024 - 1:09 PM (Name: JamieEaston)1"=120'2022-02JULY 2024CITY OF SARATOGA SPRINGSNEW YORKFig-1JWEJWEJWEJWEEP LAND SERVICES LLC621 COLUMBIA STREET- COHOES, NY 12047PHONE: 518-785-9000060'120'120'TAX PARCELS 165-2-70, 165-2-18, & 165-2-19NYS ROUTE 29 (WASHINGTON AVE)PRIME COMPANIES- STATION PARKTHE ALTERATION OF THIS MATERIAL INANY WAY, UNLESS DONE UNDER THEDIRECTION OF A COMPARABLEPROFESSIONAL, (I.E.) ARCHITECT FORAN ARCHITECT, ENGINEER FOR ANENGINEER OR LANDSCAPE ARCHITECTFOR A LANDSCAPE ARCHITECT, IS AVIOLATION OF THE NEW YORK STATEEDUCATION LAW AND/OR REGULATIONSAND IS A CLASS "A" MISDEMEANOR.STORMWATER MAINTENANCE MAPINFILTRATIONBASINHYDRODYNAMICUNITHYDRODYNAMICUNITHYDRODYNAMICUNITINFILTRATIONARRAYWET SWALE New York State Stormwater Management Design Manual Appendix G Infiltration Trench Operation, Maintenance, and Management Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: MAINTENANCE ITEM SATISFACTORY / UNSATISFACTORY COMMENTS 1. Debris Cleanout (Monthly) Trench surface clear of debris Inflow pipes clear of debris Overflow spillway clear of debris Inlet area clear of debris 2. Sediment Traps or Forebays (Annual) Obviously trapping sediment Greater than 50% of storage volume remaining 3. Dewatering (Monthly) Trench dewaters between storms 4. Sediment Cleanout of Trench (Annual) No evidence of sedimentation in trench Sediment accumulation doesn=t yet require cleanout 5. Inlets (Annual) G-6 New York State Stormwater Management Design Manual Appendix G MAINTENANCE ITEM SATISFACTORY / UNSATISFACTORY COMMENTS Good condition No evidence of erosion 6. Outlet/Overflow Spillway (Annual) Good condition, no need for repair No evidence of erosion 7. Aggregate Repairs (Annual) Surface of aggregate clean Top layer of stone does not need replacement Trench does not need rehabilitation Comments: Actions to be Taken: G-7 New York State Stormwater Management Design Manual Appendix G Open Channel Operation, Maintenance, and Management Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: MAINTENANCE ITEM SATISFACTORY/ UNSATISFACTORY COMMENTS 1. Debris Cleanout (Monthly) Contributing areas clean of debris 2. Check Dams or Energy Dissipators (Annual, After Major Storms) No evidence of flow going around structures No evidence of erosion at downstream toe Soil permeability Groundwater / bedrock 3. Vegetation (Monthly) Mowing done when needed Minimum mowing depth not exceeded No evidence of erosion Fertilized per specification 4. Dewatering (Monthly) Dewaters between storms G-13 New York State Stormwater Management Design Manual Appendix G MAINTENANCE ITEM SATISFACTORY/ UNSATISFACTORY COMMENTS 5. Sediment deposition (Annual) Clean of sediment 6. Outlet/Overflow Spillway (Annual) Good condition, no need for repairs No evidence of erosion Comments: Actions to be Taken: G-14 CDS Guide Operation, Design, Performance and Maintenance ENGINEERED SOLUTIONS 2 CDS® Using patented continuous deflective separation technology, the CDS system screens, separates and traps debris, sediment, and oil and grease from stormwater runoff. The indirect screening capability of the system allows for 100% removal of floatables and neutrally buoyant material without blinding. Flow and screening controls physically separate captured solids, and minimize the re-suspension and release of previously trapped pollutants. Inline units can treat up to 6 cfs, and internally bypass flows in excess of 50 cfs (1416 L/s). Available precast or cast-in- place, offline units can treat flows from 1 to 300 cfs (28.3 to 8495 L/s). The pollutant removal capacity of the CDS system has been proven in lab and field testing. Operation Overview Stormwater enters the diversion chamber where the diversion weir guides the flow into the unit’s separation chamber and pollutants are removed from the flow. All flows up to the system’s treatment design capacity enter the separation chamber and are treated. Swirl concentration and screen deflection force floatables and solids to the center of the separation chamber where 100% of floatables and neutrally buoyant debris larger than the screen apertures are trapped. Stormwater then moves through the separation screen, under the oil baffle and exits the system. The separation screen remains clog free due to continuous deflection. During the flow events exceeding the treatment design capacity, the diversion weir bypasses excessive flows around the separation chamber, so captured pollutants are retained in the separation cylinder. Design Basics There are three primary methods of sizing a CDS system. The Water Quality Flow Rate Method determines which model size provides the desired removal efficiency at a given flow rate for a defined particle size. The Rational Rainfall Method™ or the and Probabilistic Method is used when a specific removal efficiency of the net annual sediment load is required. Typically in the Unites States, CDS systems are designed to achieve an 80% annual solids load reduction based on lab generated performance curves for a gradation with an average particle size (d50) of 125 microns (μm). For some regulatory environments, CDS systems can also be designed to achieve an 80% annual solids load reduction based on an average particle size (d50) of 75 microns (μm) or 50 microns (μm). Water Quality Flow Rate Method In some cases, regulations require that a specific treatment rate, often referred to as the water quality design flow (WQQ), be treated. This WQQ represents the peak flow rate from either an event with a specific recurrence interval, e.g. the six-month storm, or a water quality depth, e.g. 1/2-inch (13 mm) of rainfall. The CDS is designed to treat all flows up to the WQQ. At influent rates higher than the WQQ, the diversion weir will direct most flow exceeding the WQQ around the separation chamber. This allows removal efficiency to remain relatively constant in the separation chamber and eliminates the risk of washout during bypass flows regardless of influent flow rates. Treatment flow rates are defined as the rate at which the CDS will remove a specific gradation of sediment at a specific removal efficiency. Therefore the treatment flow rate is variable, based on the gradation and removal efficiency specified by the design engineer. Rational Rainfall Method™ Differences in local climate, topography and scale make every site hydraulically unique. It is important to take these factors into consideration when estimating the long-term performance of any stormwater treatment system. The Rational Rainfall Method combines site-specific information with laboratory generated performance data, and local historical precipitation records to estimate removal efficiencies as accurately as possible. Short duration rain gauge records from across the United States and Canada were analyzed to determine the percent of the total annual rainfall that fell at a range of intensities. US stations’ depths were totaled every 15 minutes, or hourly, and recorded in 0.01-inch increments. Depths were recorded hourly with 1-mm resolution at Canadian stations. One trend was consistent at all sites; the vast majority of precipitation fell at low intensities and high intensity storms contributed relatively little to the total annual depth. These intensities, along with the total drainage area and runoff coefficient for each specific site, are translated into flow rates using the Rational Rainfall Method. Since most sites are relatively small and highly impervious, the Rational Rainfall Method is appropriate. Based on the runoff flow rates calculated for each intensity, operating rates within a proposed CDS system are GRATE INLET (CAST IRON HOOD FOR CURB INLET OPENING) CREST OF BYPASS WEIR (ONE EASH SIDE) INLET (MULTIPLE PIPES POSSIBLE) OIL BAFFLE SUMP STORAGESEPARATION SLAB TREATMENT SCREEN OUTLET INLET FLUME SEPARATION CYLINDER CLEAN OUT (REQUIRED) DEFLECTION PAN, 3 SIDED (GRATE INLET DESIGN) 3 determined. Performance efficiency curve determined from full scale laboratory tests on defined sediment PSDs is applied to calculate solids removal efficiency. The relative removal efficiency at each operating rate is added to produce a net annual pollutant removal efficiency estimate. Probabilistic Rational Method The Probabilistic Rational Method is a sizing program Contech developed to estimate a net annual sediment load reduction for a particular CDS model based on site size, site runoff coefficient, regional rainfall intensity distribution, and anticipated pollutant characteristics. The Probabilistic Method is an extension of the Rational Method used to estimate peak discharge rates generated by storm events of varying statistical return frequencies (e.g. 2-year storm event). Under the Rational Method, an adjustment factor is used to adjust the runoff coefficient estimated for the 10-year event, correlating a known hydrologic parameter with the target storm event. The rainfall intensities vary depending on the return frequency of the storm event under consideration. In general, these two frequency dependent parameters (rainfall intensity and runoff coefficient) increase as the return frequency increases while the drainage area remains constant. These intensities, along with the total drainage area and runoff coefficient for each specific site, are translated into flow rates using the Rational Method. Since most sites are relatively small and highly impervious, the Rational Method is appropriate. Based on the runoff flow rates calculated for each intensity, operating rates within a proposed CDS are determined. Performance efficiency curve on defined sediment PSDs is applied to calculate solids removal efficiency. The relative removal efficiency at each operating rate is added to produce a net annual pollutant removal efficiency estimate. Treatment Flow Rate The inlet throat area is sized to ensure that the WQQ passes through the separation chamber at a water surface elevation equal to the crest of the diversion weir. The diversion weir bypasses excessive flows around the separation chamber, thus preventing re-suspension or re-entrainment of previously captured particles. Hydraulic Capacity The hydraulic capacity of a CDS system is determined by the length and height of the diversion weir and by the maximum allowable head in the system. Typical configurations allow hydraulic capacities of up to ten times the treatment flow rate. The crest of the diversion weir may be lowered and the inlet throat may be widened to increase the capacity of the system at a given water surface elevation. The unit is designed to meet project specific hydraulic requirements. Performance Full-Scale Laboratory Test Results A full-scale CDS system (Model CDS2020-5B) was tested at the facility of University of Florida, Gainesville, FL. This CDS unit was evaluated under controlled laboratory conditions of influent flow rate and addition of sediment. Two different gradations of silica sand material (UF Sediment & OK-110) were used in the CDS performance evaluation. The particle size distributions (PSDs) of the test materials were analyzed using standard method “Gradation ASTM D-422 “Standard Test Method for Particle-Size Analysis of Soils” by a certified laboratory. UF Sediment is a mixture of three different products produced by the U.S. Silica Company: “Sil-Co-Sil 106”, “#1 DRY” and “20/40 Oil Frac”. Particle size distribution analysis shows that the UF Sediment has a very fine gradation (d50 = 20 to 30 μm) covering a wide size range (Coefficient of Uniformity, C averaged at 10.6). In comparison with the hypothetical TSS gradation specified in the NJDEP (New Jersey Department of Environmental Protection) and NJCAT (New Jersey Corporation for Advanced Technology) protocol for lab testing, the UF Sediment covers a similar range of particle size but with a finer d50 (d50 for NJDEP is approximately 50 μm) (NJDEP, 2003). The OK-110 silica sand is a commercial product of U.S. Silica Sand. The particle size distribution analysis of this material, also included in Figure 1, shows that 99.9% of the OK-110 sand is finer than 250 microns, with a mean particle size (d50) of 106 microns. The PSDs for the test material are shown in Figure 1. Figure 1. Particle size distributions Tests were conducted to quantify the performance of a specific CDS unit (1.1 cfs (31.3-L/s) design capacity) at various flow rates, ranging from 1% up to 125% of the treatment design capacity of the unit, using the 2400 micron screen. All tests were conducted with controlled influent concentrations of approximately 200 mg/L. Effluent samples were taken at equal time intervals across the entire duration of each test run. These samples were then processed with a Dekaport Cone sample splitter to obtain representative sub-samples for Suspended Sediment Concentration (SSC) testing using ASTM D3977-97 “Standard Test Methods for Determining Sediment Concentration in Water Samples”, and particle size distribution analysis. Results and Modeling Based on the data from the University of Florida, a performance model was developed for the CDS system. A regression analysis was used to develop a fitting curve representative of the scattered data points at various design flow rates. This model, which demonstrated good agreement with the laboratory data, can then be used to predict CDS system performance with respect 4 to SSC removal for any particle size gradation, assuming the particles are inorganic sandy-silt. Figure 2 shows CDS predictive performance for two typical particle size gradations (NJCAT gradation and OK-110 sand) as a function of operating rate. Figure 2. CDS stormwater treatment predictive performance for various particle gradations as a function of operating rate. Many regulatory jurisdictions set a performance standard for hydrodynamic devices by stating that the devices shall be capable of achieving an 80% removal efficiency for particles having a mean particle size (d50) of 125 microns (e.g. Washington State Department of Ecology — WASDOE - 2008). The model can be used to calculate the expected performance of such a PSD (shown in Figure 3). The model indicates (Figure 4) that the CDS system with 2400 micron screen achieves approximately 80% removal at the design (100%) flow rate, for this particle size distribution (d50 = 125 μm). Figure 3. WASDOE PSD Figure 4. Modeled performance for WASDOE PSD. Maintenance The CDS system should be inspected at regular intervals and maintained when necessary to ensure optimum performance. The rate at which the system collects pollutants will depend more heavily on site activities than the size of the unit. For example, unstable soils or heavy winter sanding will cause the grit chamber to fill more quickly but regular sweeping of paved surfaces will slow accumulation. Inspection Inspection is the key to effective maintenance and is easily performed. Pollutant transport and deposition may vary from year to year and regular inspections will help ensure that the system is cleaned out at the appropriate time. At a minimum, inspections should be performed twice per year (e.g. spring and fall) however more frequent inspections may be necessary in climates where winter sanding operations may lead to rapid accumulations, or in equipment washdown areas. Installations should also be inspected more frequently where excessive amounts of trash are expected. The visual inspection should ascertain that the system components are in working order and that there are no blockages or obstructions in the inlet and separation screen. The inspection should also quantify the accumulation of hydrocarbons, trash, and sediment in the system. Measuring pollutant accumulation can be done with a calibrated dipstick, tape measure or other measuring instrument. If absorbent material is used for enhanced removal of hydrocarbons, the level of discoloration of the sorbent material should also be identified 5 during inspection. It is useful and often required as part of an operating permit to keep a record of each inspection. A simple form for doing so is provided. Access to the CDS unit is typically achieved through two manhole access covers. One opening allows for inspection and cleanout of the separation chamber (cylinder and screen) and isolated sump. The other allows for inspection and cleanout of sediment captured and retained outside the screen. For deep units, a single manhole access point would allows both sump cleanout and access outside the screen. The CDS system should be cleaned when the level of sediment has reached 75% of capacity in the isolated sump or when an appreciable level of hydrocarbons and trash has accumulated. If absorbent material is used, it should be replaced when significant discoloration has occurred. Performance will not be impacted until 100% of the sump capacity is exceeded however it is recommended that the system be cleaned prior to that for easier removal of sediment. The level of sediment is easily determined by measuring from finished grade down to the top of the sediment pile. To avoid underestimating the level of sediment in the chamber, the measuring device must be lowered to the top of the sediment pile carefully. Particles at the top of the pile typically offer less resistance to the end of the rod than consolidated particles toward the bottom of the pile. Once this measurement is recorded, it should be compared to the as-built drawing for the unit to determine weather the height of the sediment pile off the bottom of the sump floor exceeds 75% of the total height of isolated sump. Cleaning Cleaning of a CDS systems should be done during dry weather conditions when no flow is entering the system. The use of a vacuum truck is generally the most effective and convenient method of removing pollutants from the system. Simply remove the manhole covers and insert the vacuum hose into the sump. The system should be completely drained down and the sump fully evacuated of sediment. The area outside the screen should also be cleaned out if pollutant build-up exists in this area. In installations where the risk of petroleum spills is small, liquid contaminants may not accumulate as quickly as sediment. However, the system should be cleaned out immediately in the event of an oil or gasoline spill. Motor oil and other hydrocarbons that accumulate on a more routine basis should be removed when an appreciable layer has been captured. To remove these pollutants, it may be preferable to use absorbent pads since they are usually less expensive to dispose than the oil/water emulsion that may be created by vacuuming the oily layer. Trash and debris can be netted out to separate it from the other pollutants. The screen should be cleaned to ensure it is free of trash and debris. Manhole covers should be securely seated following cleaning activities to prevent leakage of runoff into the system from above and also to ensure that proper safety precautions have been followed. Confined space entry procedures need to be followed if physical access is required. Disposal of all material removed from the CDS system should be done in accordance with local regulations. In many jurisdictions, disposal of the sediments may be handled in the same manner as the disposal of sediments removed from catch basins or deep sump manholes. Check your local regulations for specific requirements on disposal. 6 CDS Diameter Distance from Water Surface Sediment Model to Top of Sediment Pile Storage Capacity ft m ft m yd3 m3 CDS2015-4 4 1.2 3.0 0.9 0.5 0.4 CDS2015 5 1.5 3.0 0.9 1.3 1.0 CDS2020 5 1.5 3.5 1.1 1.3 1.0 CDS2025 5 1.5 4.0 1.2 1.3 1.0 CDS3020 6 1.8 4.0 1.2 2.1 1.6 CDS3030 6 1.8 4.6 1.4 2.1 1.6 CDS3035 6 1.8 5.0 1.5 2.1 1.6 CDS4030 8 2.4 4.6 1.4 5.6 4.3 CDS4040 8 2.4 5.7 1.7 5.6 4.3 CDS4045 8 2.4 6.2 1.9 5.6 4.3 Table 1: CDS Maintenance Indicators and Sediment Storage Capacities Note: To avoid underestimating the volume of sediment in the chamber, carefully lower the measuring device to the top of the sediment pile. Finer silty particles at the top of the pile may be more difficult to feel with a measuring stick. These finer particles typically offer less resistance to the end of the rod than larger particles toward the bottom of the pile. 7 CDS Inspection & Maintenance Log CDS Model: Location: Water Floatable Describe Maintenance Date depth to Layer Maintenance Personnel Comments sediment1 Thickness2 Performed —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— 1. The water depth to sediment is determined by taking two measurements with a stadia rod: one measurement from the manhole opening to the top of the sediment pile and the other from the manhole opening to the water surface. If the difference between these measurements is less than the values listed in table 1 the system should be cleaned out. Note: to avoid underestimating the volume of sediment in the chamber, the measuring device must be carefully lowered to the top of the sediment pile. 2. For optimum performance, the system should be cleaned out when the floating hydrocarbon layer accumulates to an appreciable thickness. In the event of an oil spill, the system should be cleaned immediately. PROJECT #SHEET #OF:PAGE #OF: MADE BY: DATE: PROJECT:CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: Estimated Annual Operation and Maintenance Costs associated with the Stormwater Management Practices (SMP) We Swale Mulch Replacement Wet Swale Maintenance Mowing Basin Repair Private Closed Drainage System Subtotal: Contingency (15%): (1) Included in landscaping contract Total: (2) Detailed maintenance guidelines are provided in NYS Stormwater Management Design Manual Notes:and Stormwater Pollution Prevention Plan developed for this project.Estimated Total Annual Cost3, say: (3) Estimated annual costs should be adjusted for inflation, recommend 3% annually. Costs are in 2024 dollars. 10,000$ 2,000$ 1 20,000$ 0.10 1 4,000$ Disposal 4,000$ 10-Year 2 Clean, Remove and dispose of sediment from Closed Drainage System/Hydrodyanamic Units Crew Day 10,000$ 1 0.10 2 6/20/2024 12022-02 2 Station Park Subdivision 1 JWE Estimated Operation and Maintenance Costs Annual Cost Frequency (per year) Maintenance Interval (years) Cost Unit of Measurement Estimated Frequency Unit Cost Annual Each 1 1,500$ Each Maintenance Item Estimated Quantity 13,100$ Lump Sum 20,000$ 1,000$ 1,710$ 11,400$ 10 10 Inspection & Report by Qualified Professional 1,500$ 1 1,500$ 1.00 Annual Inspection 1 Lump Sum 2,000$ 1 2,000$ 1.00 13,110$ 10 0.10 400$ 1,000$ 1.00 2,000$ 1,000$ 1 1,000$ Lump Sum 2,000$ 1 2,000$ 1 1 1.00 2,000$ Lump Sum 1,500$ 1 1,500$ 1 1.00 1,500$ 1 PROJECT #SHEET #OF:PAGE #OF: MADE BY: DATE: PROJECT:CHKD BY: DATE: SUBJECT:REVISED BY: DATE: CHKD BY: DATE: Suggested Annual funding, accounting for inflation Estimated Total Annual Cost: 39,313$ 29,995$ 28,022$ 37,801$ 29,121$ 27,272$ 13,110$ Inflation Rate 24,467$ 25,874$ 32,312$ 31,070$ 21,364$ 22,319$ 26,558$ 25,140$ 26,650$ 23,712$ 13,634$ 4.00%Year 2.75% 3.00% 13,110$ 2024 13,110$ 13,110$ 2.50% 28,792$ 30,895$ 40,886$ 27,449$ 34,949$ 26,542$ 28,273$ 23,812$ 25,120$ 29,584$ 31,821$ 42,521$ 36,347$ 21,669$ 25,537$ 25,831$ 22,555$ 23,678$ 28,726$ 33,605$ 23,175$ 24,388$ 29,875$ 19,694$ 20,425$ 23,610$ 21,951$ 22,988$ 27,621$ 20,235$ 21,038$ 24,555$ 20,792$ 18,654$ 19,252$ 21,829$ 19,167$ 19,830$ 22,702$ 17,669$ 18,147$ 20,182$ 18,155$ 18,692$ 20,990$ 16,736$ 17,106$ 18,660$ 17,196$ 17,619$ 19,406$ 15,852$ 16,124$ 17,252$ 16,288$ 16,607$ 17,942$ 14,222$ 15,015$ 15,198$ 15,950$ 15,427$ 15,654$ 16,588$ 14,747$ 14,613$ 14,755$ 2053 2054 2048 2049 2050 2051 15,337$ 2044 2045 24,913$ 2047 2040 2041 2042 2043 21,482$ 2034 15,204$ 15,584$ 2052 2035 2036 2037 2038 2039 23,134$ 2032 16,782$ 2046 18,524$ 18,987$ 19,462$ 20,958$ 22,570$ 19,948$ 22,019$ 14,471$ 14,833$ 2028 2029 2030 2031 26,828$ 27,499$ 20,447$ 17,201$ 17,631$ 18,072$ 26,174$ 25,536$ 24,305$ Stormwater Management Practices 15,973$ 16,373$ 2033 13,471$ 13,503$ 14,326$ 2027 14,118$ Estimated Operation and Maintenance Costs 13,438$ 13,774$ 13,841$ 13,908$ 14,180$ 13,110$ 2025 2026 2022-02 2 Station Park Subdivision 2 22 6/10/2024 SMP O_M Costs - template.xls.xls Annual Adjustment