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Home My WebLink About20230233 Station Lane Site Plan Water Sewer Letter Report 2023 12 212452 STATE ROUTE 9 01 LAN S I M O E N G I ICI E E R I N G P C MALTA� NY 12020 T[516) 899-!5243 F (51 B) 699-5245 December 21, 2023 Mark Torpey, Planning Board Chairman City Hall 474 Broadway Saratoga Springs, NY 12866 RE: Water/Sewer Letter Report — Faden — West Ave Site Plan (Revised) Dear Mr. Torpey: The Faden — West Ave Site Plan project proposes a 4-story mixed -use building containing retail space, an eating and drinking establishment, and multifamily rental units. The project is located on the northwest corner of West Avenue and Station Lane in the City of Saratoga Springs, New York. The proposed project includes the 22,955 SF footprint building, indoor basement level parking and outdoor parking behind the building, landscaping, an outdoor eating area, and a public civic space consisting of a proposed nature trail. The project parcel encompasses approximately 2.00 acres, and the tax map identification number is 165.-2- 76.2. This letter/report describes the water use and wastewater generation forthe proposed development. Public water service and sanitary sewer services are proposed to be provided bythe City of Saratoga Springs Department of Public Works. WASTEWATER DEMANDS The wastewater generated by the proposed development has been calculated based on the separate uses within the building. Per the "New York State Design Standard for Intermediate Sized Wastewater Treatment Systems" wastewater generated by the proposed retail space has been calculated based on 0.1gallons per day (gpd) per square foot, while the restaurant wastewater generation rate was calculated based on 35 gpd per seat. Wastewater generated by the residential development has been calculated based on the 10 State Standards of 100 gallons per capita per day (gpcpd) with an estimated population density of 2.0 residents per dwelling unit. The Average Daily Wastewater Flows and Peak Hour Wastewater Flows generated from the proposed development are 13,426 gpd and 38.97 gpm, respectively. A detailed outline of the wastewater flow calculations are as follows: West Ave —Site Plan, & Special Use Permit— Development consists of approximately 8,330 SF of retail, a 2,100 SF restaurant with approximately 50 seats, and 71 multifamily units. Retail Space: Proposed 8,330 SF Retail Space = (8,330 sf) x (0.1 gpd/sf) = 833 gpd Design Average Daily Wastewater Flow = Total Wastewater Flow with 20% reduction for water saving measures = 833 gpd x 80% = 666 gpd Equivalent Population = 666 gpd / 100 gpcpd = 7 people Page 2 Restaurant Space: Restaurant = (50 seats) x (35 gpd/seat) = 1,750 gpd = 1,750 gpd Design Average Daily Wastewater Flow = Total Wastewater Flow with 20% reduction for water saving measures = 1,750 gpd x 80% = 1,400 gpd Equivalent Population = Estimated to be 1,400 gpd/100 gpcpd = 14 people Multifamily Units: Population = (71 units) x (2.0 residents/unit) = 142 persons Design Average Daily Wastewater Flow = (142 persons) x 100gpcpd with 20% reduction for water saving measures = 14,200 gpd x 80% = 11,360 gpd Total Design Average Daily Wastewater Flow = 666 gpd + 1,400 gpd + 11,360 gpd = 13,426 gpd Total Population = 7 + 14 + 142 = 163 persons Peak Hour Factor (P = population in thousands) = 18 + Pl/z = (18 + 0.163'1') = 4.18 (4 + Pl/z) (4 + 0.1631/2) PHF = 4.18 Cumulative Peak Hour Wastewater Flow = (Average Daily Wastewater Flow) x (Peak Hour Factor) = (13,426 gpd) x (4.18) = 56,121 gpd = 38.97 gpm (calculated design flow, required flow) Pipe Size Required — Based on Manning's formula using an "n" value of 0.013 for PVC and using the cumulative peak hour waste hour flow calculated above Q = x 2 iR1 (Calculated design capacity and velocity) Trial Pipe size = 6" Pipe Slope = 0.02 ft/ft minimum 60% Full Velocity = 4.70 fps 60% Full Capacity = 0.58 cfs = 260.32 gpm 260 gpm (design capacity @ 60%) > 38.97 gpm (required capacity) Therefore Use 6" Diameter Pipe for all Gravity Service Laterals Page 3 Wastewater flows from the proposed development will be collected on site and conveyed via gravity piping to the existing public sewer main along Station Lane and ultimately to the existing pump station on Station Lane immediately adjacent to the project site. The existing pump station on Station Lane was identified to have capacity deficiencies. These deficiencies were outlined in the Engineer's Report prepared by Bergmann Associates dated August 16, 2017 for the Station Park Project that was previously proposed to the west of the Faden - West Ave project. This report identified four potential projects within the area that would contribute to the existing pump station and cause capacity issues. The four projects included the Station Park Project, Askew Apartments, Intrada Development and the Faden — West Ave project. At that time, the anticipated flows that were included within the Bergmann Associates report for the Faden — West Ave project were as follows: Average Daily Wastewater Flow = 18,393 gpd Cumulative Peak Hour Wastewater Flow = 52 gpm Currently proposed for the Faden — West Ave project are as follow: Average Daily Wastewater Flow = 13,426 gpd Cumulative Peak Hour Wastewater Flow = 38.97gpm 13,426 gpd (currently proposed) < 18,393 gpd (Bergmann Associates report) 38.97 gpm (currently proposed) < 52 gpm (Bergmann Associates report) The Bergmann Associates report proposed upgrades to the existing pump station with each project contributing to the cost of the upgrades. The Station Park project did not advance while the remaining three projects continued. Most notably, the Intrada development advanced through approvals and construction first. As a part of their review and approval process they reevaluated the pumps station improvements with the elimination of the Station Park project before funding and performing the improvements to the pump station as a part of their construction. The owners of the Intrada project completed the pump station upgrades in 2019. The Askew Apartments project is currently under construction and has since reimbursed the Intrada project owners for that project's share of the pump station upgrade costs. The developers of the Faden — West Ave project are committed to contributing their portion of the pump station upgrade costs as the project advances toward construction and they have recently been in contact with the owners of the Intrada development regarding that payment. Based on the above it is expected that the existing and proposed sanitary system has adequate capacity to collect and convey the anticipated flow and that the project will not have an adverse impact on the existing system. WATER DEMANDS The water usage rates have been calculated for the 71 residential multifamily units based on the 10 State Standards of 100 gpdpc, with an anticipated population of 2.0 residents per unit. Water usage rates for the 8,330 sf of retail space is based on 0.1 gpd/SF per the "New York State Design Standard for Intermediate Sized Wastewater Treatment Systems", while the restaurant water demand was calculated based on a usage rate of 35 gpd/seat. The Average Day, Max Day, and Peak Hour Water usage rates usage for the site have Page 4 been calculated to be 13,426 gpd, 22,153 gpd, and 41.96 gpm, respectively. A detailed outline of the water demand calculations are as follows: Retail Snac : Retail = 8,330 SF x 0.1 gpd/sf = 833 gpd Water Demand Average Day with 20% water reduction for water saving fixtures: = 833 gpd x 80% = 666 gpd Multifamily Units: Population = (71 units) x (2.0 residents/unit) = 142 persons Design Average Daily Wastewater Flow = (142) x 100 gpcpd x 20% reduction for water saving measures = 14,200 gpd x 80% = 11,360 gpd Restaurant Space: Restaurant = (50 seats) x (35 gpd/seat) = 1,750 gpd Water Demand Average Day with 20% water reduction for water saving fixtures: = 1,750 gpd x 80% = 1,400 gpd Total = 666 gpd + 11,360 gpd + 1,400 gpd= 13,426 gpd Water Demand Rates (Based on National Average) Average Day = 100% of average daily demand rate Max Day = 165% of average daily demand rate Max Hour = 450% of average daily demand rate Water Demand For Service Area Average Day = (100%) x (13,426 gpd) = 13,426 gpd = 9.32 gpm Max Day = (165%) x (13,426 gpd) = 22,153 gpd = 15.38 gpm Max Hour = (450%) x (13,426 gpd) = 60,417 gpd = 41.96 gpm The water service connection to the City of Saratoga Springs Public Works water system will provide the domestic and fire protection needs of the proposed development. The proposed building will have an automatic sprinkler system. The project proposes one dual domestic and fire protection 6" DIP connection into the existing 8" DIP located along the west side of West Avenue. The connection shall utilize a tapping sleeve and valve to prevent disruption to the water supply during construction. The proposed water system is shown in the attached plan set. The estimated water usage and wastewater flows for the Faden — West Ave Site Plan are within the available capacity the water and wastewater systems in the area. The project applicant has agreed to participate and contribute to the local sanitary sewer improvements that will improve the existing systems. Therefore, it is expected that the connection of the water and sanitary systems will not have an adverse impact on the Page 5 existing utilities. Please review this letter/report and pending your approval please provide an approval letter for this connection. Please contact me at 899-5243 ext. 104 if you have any questions or require any additional information. Thank you. Sincerely, LANSING ENGINEERING, RC Michael T. Vaillant, PE Cc: Russell Faden (Applicant)