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Home My WebLink About20221061 West Ave & Station Lane Sketch Site Plan Water Sewer Letter Report July 06, 2022 Mark Torpey, Planning Board Chairman City Hall 474 Broadway Saratoga Springs, NY 12866 RE: Water/Sewer Letter Report – Faden – West Ave Site Plan Dear Mr. Torpey: The Faden – West Ave Site Plan project proposes a new 4 story mixed use building containing retail space, an eating and drinking establishment and multifamily units with parking for residents, customers and employees with a footprint of 22,984‐sf. The development is located on the corner of West Avenue and Station Lane in the City of Saratoga Springs, New York. The project parcel encompasses approximately 2.00 acres, and the tax map identification number is 165.‐2‐76.2. This letter/report will describe the water use and wastewater generation for the proposed development. Public water service and sanitary sewer services are proposed to be provided by the 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 for the buildings. Wastewater generated by the proposed retail development has been calculated based on 0.1 gpd per square foot (from the “New York State Design Standard for Intermediate Sized Wastewater Treatment Systems”). 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 12,354 gpd and 36.29 gpm, respectively. A detailed outline of the wastewater flow calculations are as follows: West Ave – Site Plan, & Special Use Permit – Development consists of approximately 2,280‐sf of retail, 13,900‐sf of office space, a 3,760‐sf restaurant and 56 multifamily units. Retail Space: Proposed 2,280 sf Retail Space = (2,280 sf) x (0.1 gpd/sf) = 228 gpd Design Average Daily Wastewater Flow = Total Wastewater Flow with 20% reduction for water saving measures = 228 gpd x 80% = 182.4 gpd Equivalent Population = 182.4 gpd / 100 gpcpd = 2 people Restaurant Space: Restaurant = (60 seats) x (35 gpd/seat) = 2,100 gpd = 2,100 gpd Page 2 Equivalent Population = Estimated to be 2,100 gpd/100 gpcpd = 21 people Office Space: Office = (13,900 ft2) x (0.1gpd/ ft2) = 1,390 gpd = 1,390 gpd x 80% = 1,112 gpd Population Equivalent = Estimated to be 1,112 gpd/100 gpcpd = 12 people Multifamily Units: Population = (56 units) x (2.0 residents/unit) = 112 persons Design Average Daily Wastewater Flow = (112 persons) x 100gpcpd with 20% reduction for water saving measures = 11,200 gpd x 80% = 8,960 gpd Total Design Average Daily Wastewater Flow = 182 gpd + 8,960 gpd + 2,100 gpd + 1,112 gpd = 12,354 gpd Total Population = 2 + 21 + 12 + 112 = 147 persons Peak Hour Factor (P = population in thousands) = (18 + P1/2) = (18 + 0.1471/2) = 4.19 (4 + P1/2) (4 + 0.1471/2) PHF = 4.19 Cumulative Peak Hour Wastewater Flow = (Average Daily Wastewater Flow) x (Peak Hour Factor) = (12,354 gpd) x (4.19) = 51,763 gpd = 35.95 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 (Calculated design capacity and velocity) Trial Pipe size = 6” Pipe Slope = 0.02 ft/ft minimum Full Velocity = 4.05fps Full Capacity = 0.80 cfs = 357.08 gpm 357 gpm (design capacity) > 35.95 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 has been 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 proposed 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 4 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 = 12,354 gpd Cumulative Peak Hour Wastewater Flow = 35.95gpm 12,354 gpd (currently proposed) < 18,393 gpd (Bergmann Associates report) 35.95 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 approvals and construction they reevaluated the pumps station improvements with the elimination of the Station Park project, and they were required to fund and perform the improvements to the pump station as a part of their construction. Both the Askew Apartments and the Faden – West Ave project are aware of the improvements that were required for the Intrada Development and have agreed to provide cost sharing proportionate to the contributing flows. 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 56 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 2,280 sf of retail space is based on 0.1 gpd/sf (from the “New York State Design Standard for Intermediate Sized Wastewater Treatment Systems”). The Average Day, Max Day, and Max Hour Water usage rates usage for the site have been calculated to be 12,354 gpd, 20,384 gpd, and 38.61 gpm, respectively. A detailed outline of the water demand calculations are as follows: Page 4 Retail Space: Retail = 2,280 sf x 0.1 gpd/sf = 228 gpd Water Demand Average Day with 20% water reduction for water saving fixtures: = 228 gpd x 80% = 182.4 gpd Multifamily Units: Population = (56 units) x (2.0 residents/unit) = 112 persons Design Average Daily Wastewater Flow = (112) x 100 gpcpd x 20% reduction for water saving measures = 11,200 gpd x 80% = 8,960 gpd Office Space: Office = (13,900 ft2) x (0.1gpd/ ft2) = 1,390 gpd = 1,390 gpd x 80% = 1,112 gpd Restaurant Space: Restaurant = (60 seats) x (35 gpd/seat) = 2,100 gpd = 2,100 gpd Total = 182 gpd + 8,960 gpd + 1,112 gpd + 2,100 gpd= 12,354 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 (12,354 gpd) = 12,354 gpd = 8.58 gpm Max Day = (165%) x (12,354 gpd) = 20,384 gpd = 14.16 gpm Max Hour = (450%) x (12,354 gpd) = 55,593 gpd = 38.61 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 buildings will have automatic sprinkler systems. The project proposes two 6” DIP connection into the proposed 6” DIP water main that will extend to the existing 8” DIP located along the south side of Station Lane. 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. Page 5 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 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. 102 if you have any questions or require any additional information. Thank you. Sincerely, LANSING ENGINEERING, PC Yates Scott Lansing, PE, CPESC, CPSWQ Cc: Russell Faden (Applicant)