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Engineer’s Report December 2025 II Discussion A. Sanitary Sewers 1. System Description and Design Flows The proposed building will be serviced by a six-inch PVC sewer lateral installed south of the Quaker Road ROW (US 20A) crossing through the property to the east within a twenty-foot private utility easement then crosses under Quaker Road (US 20A) to the existing sanitary manhole within the westbound lane. The existing sanitary manhole is owned and operated by the Village of East Aurora and is tributary to the East Aurora Water Resource Recovery Facility (WRRF) within ECSD #8. The East Aurora WRRF is roughly 1,200-feet east of the proposed site along Mill Street. The estimated maximum flow rate for the proposed building is based on 250 gallons per day (gpd) per dental chair as per the New York State Design Standards for Intermediate Sized Wastewater Treatment Systems dated March 5th, 2014. The proposed building will have 7 dental chairs making the estimated maximum flow rate 1,750 gpd (7 dental chairs x 250 gpd per dental chair) or 0.00175 million gallons per day (mgd). With the peak design flow being less than 2,500 gpd, a downstream sanitary sewer capacity analysis is not required. B. Water 1. Domestic System Description and Design Flows Water service for domestic use will be provided by a new two-inch type ‘K’ copper waterline connecting to the ECWA existing twenty-inch prestressed concrete cylinder pipe (PCCP) watermain along Quaker Road (US 20A) and running to a new curb valve and box at the northerly property. From the curb box, the two-inch water service transitions to polyethylene tubing (DR-9) then runs to the proposed building’s mechanical room located in the southeast corner of the proposed building. The two-inch domestic water service to the building is sized to accommodate a peak instantaneous water demand of 42 gpm based on the various types and quantities of plumbing fixtures proposed for the Dental Office (See Appendix B). To protect the public water supply from any potential cross contamination from the private water service, a backflow prevention device (RPZ) and water meter assembly will be installed inside the building. The RPZ and meter assembly will be designed by others. 2. Fire System Description and Design Flows Greenman-Pedersen, Inc. GPI No. WNY-2500056.00 Page 4