PB 22 10 Altera 769 LLC Filed Application with Exhibits Final Site Plan Phase 2

Project: Altera Development Company, LLC Computed By: SDP Job #: 2530-99-006 Checked By: RJC Location: Township of West Orange, Essex County, NJ Date: 6/14/2022 Drainage Area Impervious Area Curve Number HSG D - Open Space Curve HSG D - Curve Number Avg. Total Area (acres) TC (Min.) (acre) (CN) Used Area (acre) Number Wooded (CN) Used Curve (CN) Used Area Number (acre) [POI-1] - EX DA-1 0.00 98 0.00 80 0.88 77 77 0.88 18.5 [POI-2] - EX DA-2 0.97 98 0.00 80 0.94 77 88 1.92 16.1 [POI-2] - EX DA-3 1.83 98 0.24 80 0.00 77 96 2.08 6.0 4.88 [POI-2] - DA-1 0.00 98 0.20 80 0.29 77 78 0.50 18.8 [POI-2] - DA-2 UNDET 0.35 98 0.03 80 0.00 77 96 0.38 6.0 [POI-2] - DA-2A DET 0.98 98 0.11 80 0.12 77 94 1.21 14.7 [POI-2] - DA-2B DET 0.27 98 0.27 80 0.17 77 86 0.71 13.3 [POI-3] - DA-3 1.82 98

98 0.27 80 0.17 77 86 0.71 13.3 [POI-3] - DA-3 1.82 98 0.26 80 0.00 77 96 2.08 6.0 4.88 BogB D* Soil Boonton Loam, 3 to 8 percent slopes Per Essex County Soil BogBc D* Soil Boonton Loam, 0 to 8 percent slopes, extremely stony Survey & Dynamic Earth Report BouB D* Soil Boonton – Urban Land, Boonton Substratum Complex, 0 to 8 percent slopes URBONB D* Soil Urban Land, Boonton Substratum, 0 to 8 percent slopes Description Runoff Curve Number (CN) Impervious Surface 98 Open Space (lawn) (good) 80 Woods 77 * Based on laboratory testing performed by Dynamic Earth, LLC, permeability rates were less that 0.01 inches per hour which is consistent with a hydrologic soil group (HSG) D. For the purposese of the design, the site has been modeled as HSG D in the Runoff Curve Number calculations.