12 2026 02 12 Crestmont CC Stormwater Management Report

A geotechnical investigation was performed in the area of redevelopment in April 2024; refer to Appendix F for the supporting geotechnical memorandum. As part of this investigation, soil samples were collected at 19 test pit locations for laboratory permeability tests. The purpose of this testing was to confirm the hydrologic soil group classification of the in-situ soils within the proposed limit of disturbance area, which is approximately 3.93± acres. Soil type UdhalB is already classified as Hydrologic Soil Group D; therefore, not reclassification testing was performed within this soil. The number and location of these test pits is based upon the regulations set forth in Chapter 12 of the New Jersey Stormwater BMP Manual. A summary of the required and proposed geotechnical testing is summarized in Table 1 below: Table 1 – Hydrologic Soil Group Reclassification Summary Approximate Area Required Number Soil Number of Test of Disturbance of Test Pits / Mapping Pits / Permeability Test Pit IDs Within Soil Permeability Unit Tests Performed Mapping Unit (AC) Tests TP-9, TP-14, TP-15, BouB 1.20 5 5 TP-16, TP-17 HanBc 0.27 2 2 TP-11, TP-12 TP-1, TP-4, TP-5, TP-6, TP-8, TP-7, TP-10, TP- BogBc 2.37 8 12 13, TP-18, TP-19, TP- 20, TP-21 Notes: 1. Chapter 12 of the BMP Manual requires that soil profile

8, TP-19, TP- 20, TP-21 Notes: 1. Chapter 12 of the BMP Manual requires that soil profile test pits and soil borings be performed as part of the HSG reclassification. In accordance with Chapter 12 Subsection 1C, soil profiles test pits may be conducted in place of a required soil boring in all testing instances. 2. Refer to the Test Pit Location Plan, Figure 10, for BMP and test pit locations. Refer to Appendix F for supporting geotechnical investigation information including test pit and boring logs. The full geotechnical analysis and supporting laboratory data is contained in Appendix F of this report. In summary, the laboratory permeability testing at all 19 test pit locations supports the reclassification of soils within the project area’s limit of disturbance to HSG D in accordance with the New Jersey Stormwater Best Practices Manual and the NRCS National Engineering Handbook, Part 630 – Hydrology, Chapter 7 Hydrologic Soil Groups, Table 7-1: Criteria for Assignment of Hydrologic Soil Group. For the purpose of the stormwater management calculations in this report, all underlying soil within the project area’s limit of disturbance is assumed to be HSG D. All soil outside the limit of disturbance is assumed to retain its respective NRCS Web Soil Survey hydrologic soil group classification. It should be noted that the project site is located in an area of the state containing known karst 3