2025 08 15 WEH SWM CME Memo

Chairman and Members of the West Orange Township Planning Board August 15, 2025 Re: West Essex Highlands, LLC (PB 24-01) Our File No. 115.WRP0179.V01 Response To Objector’s Stormwater Management System Review Page 6 As shown within Table 1, the infiltration areas as modeled are less than (not greater than) the infiltration areas shown on the plans for BMPs 1, 8, 9 and 11. Therefore, the model does not need to be revised since it is a more conservative design. With that said, the Applicant will be required to revise the BMP infiltration areas shown on the plans to match the model for consistency purposes prior to any construction. “Table 2 provides a comparison of the number of test pits required by the NJDEP BMP Manual against those performed by the applicant. The BMP footprint as shown on the plan was used as the reference to determine the required number of test pits. Table 2: Number of Soil Test Performed for each BMP against the Minimum Number Required BMP ID 1 2 3 4 5 6 7 8 9 10 11 12 Infiltration Area, Plan (SF) 45,490 25,830 5,558 12,369 14,611 37,473 13,405 15,900 17,981 9,467 22,826 1,004 Number of Tests Provided 12 4 2 3 3 4 1 2 3 1 4 2 Number of Tests Required 6 3 2 3 3 5 3 3 3 2 4 2 Compliant (Y/N) Y Y Y Y Y N N N Y N Y Y BMPs 6, 8, and 10 are short one soil test and BMPs 7 is short two test pits. 76,425 sf of the 221,914 sf of infiltration areas are not compliant with local ordinance. Though this may seem minor, but the SHWT can vary greatly as exemplified by BMP 6 and therefore it’s important to enough testing to confirm the design conforms with standards. This is a vulnerability in the design that shows how the project is potentially not conforming to N.J.A.C. 7:8 5.4 (§25-29.4P) 7:8 5.6 (§25-29.4R) for groundwater recharge and stormwater quantity control standards.” The New Jersey Stormwater Best Management Practices (BMP) Manual provides guidance to address the standards in the Stormwater Management Rules, N.J.A.C. 7:8. N.J.A.C. 7:8 defines the New Jersey Stormwater Best Management Practices (BMP) Manual as the “manual maintained by the Department (NJDEP) providing, in part, design specifications, removal rates, calculation methods, and soil testing procedures approved by the Department as being capable of contributing to the achievement of the stormwater management standards specified in this chapter. The manual is periodically

and soil testing procedures approved by the Department as being capable of contributing to the achievement of the stormwater management standards specified in this chapter. The manual is periodically amended by S:\West Orange\Planning Board\VWRP0179.01 - West Essex Highlands, Inc\2025-08-15 - WEH - SWM Memo.docx