Stormwater Management Report Feb 2026 resubmissionrcd 2 26 2026

7. Water Quantity Control Compliance The site has been designed to reduce peak flows for the 2-, 10- and 100-year storm events as compared to the pre-development conditions. The point of analysis has been identified on the Drainage Area Maps as previously described. Below is a summary table demonstrating compliance with the flow reduction requirements. Point of Analysis #1 Storm Event Existing Peak Proposed Peak Percent Flow Rate (cfs) Flow Rate (cfs) Reduction Current 2-year 1.55 1.52 1.9% Current 10-year 2.65 2.49 6.0% Current 100-year 5.01 4.89 2.4% Projected 2-year 1.90 1.85 2.6% Projected 10-year 3.26 3.00 8.0% Projected 100- 6.55 6.40 2.3% year 8. Water Quality Compliance In accordance with the West Orange Stormwater Control Ordinance, section 25-29.4.r.2(a), major developments are required to provide 80% TSS removal for the stormwater runoff from the net increase in motor vehicle surface. The project proposed a net decrease of motor vehicle surface of 0.009 acres (0.276 acres in the existing condition and 0.267 acres in the proposed condition) therefore water quality is not required, however, the proposed bioretention basin has been designed to treat 0.064 acres of motor vehicle surface in the proposed condition to 80% TSS removal. For reference, the project proposes a net increase in overall impervious area of 0.04 acres. 9. Groundwater Recharge Compliance As determined by NJ GeoWeb Mapping, this project area falls within the Metropolitan Planning Area (PA1). Under existing conditions, the site is not covered in woody vegetation nor regrowth. In accordance with New Jersey Standard for Land Grading (revised 2017), non woody vegetated PA1 areas fall under the soil compaction exemption list as a "urban redevelopment" and is defined by NJDEP as "previously developed". Therefore, this project will not be subject to comply with ground water recharge requirements set forth in NJAC 7:8-5.4. 10. Storm Sewer Design The proposed stormwater management

viously developed". Therefore, this project will not be subject to comply with ground water recharge requirements set forth in NJAC 7:8-5.4. 10. Storm Sewer Design The proposed stormwater management collection system has been designed to have hydraulic capacity for the 25-year storm event. The Rational Method was used to determine inflow rates to each structure and Manning’s Equation was used to establish pipe capacity. In accordance with the NJDEP BMP Manual Chapter 5, weighted runoff coefficients were computed for each drainage area based on land cover and hydrologic soil group. A minimum time of concentration Mavis Tire Supply, LLC July 2025 DEC# 1956-24-04187 6 Last revised February 2026