J_2024 05 09_West Orange Stormwater Management Plan

PSE&G West Orange Switching Station West Orange, NJ Stormwater Management Report 4. Stormwater Quality Requirements For Major Development sites, NJDEP requires 80% TSS reduction for the NJDEP water quality storm event (1.25 inches over 2 hours). To demonstrate compliance with the water quality requirement NJDEP has adopted TSS removal rates for each of the Best Management Practices in the Chapter 9 of the NJDEP Stormwater BMP Manual. TRC has selected the AquaFilter/AquaSwirl manufactured treatment device for the NJDEP water quality storm. The system, manufactured by AquaShield Inc., is certified by NJDEP with a TSS removal rate for the AquaFilte/Aquaswirl is 80%. The system is to be installed under the access road south of MH-12 to filter out sediments collected in stormwater flows from the east side of the existing station. See Appendix F for detailed spec sheets from AquaShield Inc., regarding the system. In addition, a series of bioretention basins will be placed alongside the main access road directly west of the new pad to provide an 80% TSS removal rate. The basins will allow sediments from the stormwater to settle out before stormwater flows reach CB #1. Section IV: Stormwater Maintenance Schedule The stormwater management system for the proposed West Orange Switching Station Expansion Project will consist of monitoring the Aqua-Swirl/Aqua-Filter system, inspection of the transformer secondary containment area and insuring that yard stone surfaces remain in place. Maintenance activities will include the following: 1. Refer to Appendix F for maintenance of the Aqua-Swirl/Aqua-Filter system. 2. After every storm event exceeding one inch (1”) of rainfall: PSE&G shall inspect to determine that basins drain completely within seventy-two (72) hours after the storm event. If stored water fails to infiltrate seventy-two (72) hours after the end of the storm, corrective measures shall be investigated and taken as required. Remove sediment and encrusted build up avoiding mixing with native topsoil, rake or till by light equipment to restore detention capacity of particular areas. 3. Once per month (or sooner as seasonal growth necessitates): PSE&G shall remove litter and debris from the basin area, and then mow top, banks and bottom to maintain a height of between 2 to 6 inches collecting and disposing all clippings off-site. 4. Four times per year

l remove litter and debris from the basin area, and then mow top, banks and bottom to maintain a height of between 2 to 6 inches collecting and disposing all clippings off-site. 4. Four times per year (quarterly): PSE&G shall inspect stormwater basins for clogging, debris and sediment accumulation - remove as needed. Check for signs of damage to structures and erosion of banks and bottom - repair as needed. Observe for signs of petroleum contamination - remediate as needed. 5. Once per year: PSE&G shall inspect basins for undesirable plant growth such as trees, woody vegetation, weeds, etc., and remove as necessary. 6. PSE&G will inspect the yard stone surface of the switching station pad on a monthly basis to ensure it remains in place. Any evidence of off-site erosion will be corrected prior to the next expected rainfall event. TRC Engineers, Inc. 15 March 2012