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

• The proposed underdrain component consists of three parts – the sand layer, the gravel layer and the network of pipes that collect runoff and transport it to the outflow section of the system. • The capacity of the proposed underdrain is designed to allow the system to drain within 72 hours. • The system has been designed so the seasonal high-water table (SHWT) or bedrock is at least 1 foot below the bottom of the underdrain component. • At least one inspection port, with a removable cap, is proposed in the storage bed at least 3 feet from any edge. • Points of access are designed in such a way as to prevent sediment or other material from entering the system and to prevent the accumulation of standing water, which could lead to mosquito breeding. VI. RUNOFF RATES The following is a comparison of pre and post development runoff rates: PEAK RUNOFF RATES (POI-2) Design Storm Reduction Allowable Existing Runoff Proposed Runoff Difference Required Runoff 2-yr 4.04 CFS 50% 2.02 CFS 1.83 CFS -2.21 CFS 10-yr 7.19 CFS 75% 5.39 CFS 4.09 CFS -3.10 CFS 100-yr 13.54 CFS 80% 10.83 CFS 9.26 CFS -4.28 CFS PEAK RUNOFF RATES (POI-3) Design Storm Existing Runoff Proposed Runoff Difference 2-yr 9.02 CFS 7.40 CFS -1.62 CFS 10-yr 14.76 CFS 12.83 CFS -1.93 CFS 100-yr 26.22 CFS 22.52 CFS -3.70 CFS As can be seen above, the stormwater management system has been designed to not exceed the existing tributary runoff rates for the given design storms. VII. WATER QUALITY The TSS removal rate

As can be seen above, the stormwater management system has been designed to not exceed the existing tributary runoff rates for the given design storms. VII. WATER QUALITY The TSS removal rate requirement set for the Township of West Orange Land Use Ordinance and NJAC 7:8 is 80% for the net increase of motor vehicle surface. Under the proposed conditions, the runoff from the proposed rear parking lot expansion within drainage areas DA-1, DA-2A, and DA-2B will be collected via a Altera 769, LLC 8 Revised August 2022 DECPC #2530-99-006