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Since the total disturbed area remains under 1.0 acre, NYSDEC SPDES Phase II stormwater permitting requirements do not apply. 2.2 Existing (Pre-Development) Conditions Per the USDA Soil Survey, the on-site soils consist of Galen very fine sandy loam, Hamlin silt loam, and the Wayland soils complex, all of which are classified as Hydrologic Soil Group "D". (See Appendix A) 2.3 Proposed (Post-Development) Conditions The proposed site development includes construction of the following: • 2,500 square foot building addition • 2,277 +1- square foot asphalt area 2.4 Storm Water Management/Detention Facilities Stormwater quantity control calculations were performed, and the results indicate that there is no increase in runoff rates between pre- and post-development conditions; therefore, no on-site detention is required. Stormwater from the proposed asphalt area will flow in a westerly direction consistent with existing conditions, ultimately discharging to an existing swale located west of the site. From there, runoff will continue along the site's existing drainage patterns. The table below summarizes pre- and post-development runoff conditions for the drainage area discharging to the existing swale. Stormwater Management Runoff Table — for Runoff Entering Existing Swale Pre Dev Area Post Dev Area peak Runoff Peak Runoff Rate Rate (cfs) (cfs) 10 5.29 5.29 Year 25 6.56 6.56 Year Page 394 of 849