12 2026 02 12 Crestmont CC Stormwater Management Report

treating those respective areas. 3.2.4 Trash and Waste Catch basins are proposed to have Type N Eco curb pieces to prevent trash and floatables from entering the proposed conveyance systems. The BMP outlet control structures will also be fixed with trash racks and rock screens to prevent debris and floatables from entering the downstream conveyance systems. 3.3 Groundwater Recharge 3.3.1 Design Criteria Per N.J.A.C. 7:8-5.4.(b).1.i, one hundred percent (100%) of the average annual pre-construction groundwater recharge volume for the disturbed area of the project site must be maintained in the post-construction condition. A geotechnical investigation was performed, with laboratory permeability testing results indicating that site soils within the proposed development area can be reclassified to HSG D. Hydrologic soil group D soils result in zero annual groundwater recharge. Therefore, there is no groundwater recharge occurring on the project site within the proposed redevelopment area. 3.3.2 Design Methodology The groundwater recharge volume analysis is performed using the NJDEP New Jersey Groundwater Recharge Spreadsheet (NJGRS), which is based on the data and computational procedures outlined in New Jersey Geological Survey Report GSR-32. The spreadsheet compares the pre-construction and post-construction land cover types within the property’s native underlying soil classifications to develop the total annual recharge volume across the project site in both the pre-construction and post-construction conditions. The post-development annual groundwater recharge deficit for the project site is zero due to all underlying soils within the proposed disturbance area being reclassified to HSG D. 3.3.3 BMP Design All proposed BMP’s have been designed to be under-drained due to poorly draining in-situ soils, and to minimize the potential for infiltration within potential underlying karst features. 18