J_2024 05 09_West Orange Stormwater Management Plan

Stormwater Management Plan Public Service Electric and Gas Company West Orange 26kV Switching Station Project No. 144507 Revision 0 5/9/2024

Stormwater Management Plan prepared for Public Service Electric and Gas Company West Orange 26kV Switching Station West Orange, New Jersey Project No. 144507 Revision 0 5/9/2024 prepared by Burns & McDonnell Engineering Company, Inc. Kansas City, Missouri COPYRIGHT © 2024 BURNS & McDONNELL ENGINEERING COMPANY, INC.

Stormwater Management Plan Revision 0 Table of Contents Section Number EXHIBIT A EXHIBIT B APPENDIX A APPENDIX B APPENDIX C APPENDIX D APPENDIX E APPENDIX F INDEX AND CERTIFICATION Public Service Electric and Gas Company Stormwater Management Plan Project No. 144507 Report Index Section Title Site Conditions Hydrology and Hydraulics Best Management Practices Soil Erosion and Sediment Control Measures Conclusions Pre-Developed Watershed Plan Post-Developed Watershed Plan Design Notes HydroCAD Output CivilStorm Output Stormwater Maintenance Plan & Field Manuals Subsurface Investigation Reference Materials Certification [hereby certify, as a Professional Engineer in the state of New Jersey, that the information in this document was assembled under my direct personal charge. This report is not intended or represented to be suitable for reuse by the Public Service Electric and Gas Company or others without specific verification or adaptation by the Engineer. bo SPR he Michael J. Blake, P.E. J. PE: Nos 24GE05521600 O:C-A.No. 24GA28066400 Additional reference information provided by others and not certified by ‘the-above sealing Engineer. Section Number Section Title APPENDIX E APPENDIX F Subsurface Investigation Reference Materials Public Service Electric & Gas Company TOC-1 Burns & McDonnell

Stormwater Management Plan Revision 0 Table of Contents TABLE OF CONTENTS Page No. 1.0 SITE CONDITIONS ........................................................................................... 1-1 1.1 Site Description .................................................................................................... 1-1 1.2 Project Description............................................................................................... 1-1 1.3 Project Stormwater Management Requirements ................................................. 1-1 1.4 Soils...................................................................................................................... 1-2 1.5 Floodplain ............................................................................................................ 1-3 2.0 HYDROLOGY AND HYDRAULICS .................................................................. 2-1 2.1 Rainfall Data ........................................................................................................ 2-1 2.2 Runoff Data .......................................................................................................... 2-1 2.3 Stormwater Management Facilities ..................................................................... 2-3 2.4 Results .................................................................................................................. 2-6 2.5 Other Stormwater Conveyance ............................................................................ 2-8 3.0 BEST MANAGEMENT PRACTICES ................................................................ 3-1 3.1 NJDEP’s Low Impact Development Checklist.................................................... 3-1 4.0 SOIL EROSION AND SEDIMENT CONTROL MEASURES ............................ 4-1 5.0 CONCLUSIONS ................................................................................................ 5-1 APPENDIX A – DESIGN NOTES APPENDIX B – HYDROCAD OUTPUT B.1 Pre-Developed Outfall = O-AquaShield B.2 Pre-Developed Outfall = O-1 B.3 Pre-Developed Outfall = O-2 B.4 Post-Developed Outfall = O-AquaShield B.5 Post-Developed Outfall = O-1A B.6 Post-Developed Outfall = O-1B B.7 Post-Developed Outfall = O-2 B.8 Post-Developed Stormwater Conveyance = 25-Year APPENDIX C – CIVILSTORM OUTPUT APPENDIX D – STORMWATER MAINTENANCE PLAN & FIELD MANUALS APPENDIX E –SUBSURFACE

O-1B B.7 Post-Developed Outfall = O-2 B.8 Post-Developed Stormwater Conveyance = 25-Year APPENDIX C – CIVILSTORM OUTPUT APPENDIX D – STORMWATER MAINTENANCE PLAN & FIELD MANUALS APPENDIX E –SUBSURFACE INVESTIGATION APPENDIX F – REFERENCE MATERIALS Public Service Electric & Gas Company TOC-2 Burns & McDonnell

Stormwater Management Plan Revision 0 Table of Contents EXHIBITS Exhibit A: Pre-Developed Watershed Plan Exhibit B: Post-Developed Watershed Plan ***** LIST OF TABLES Page No. Table 2.1: Design Storm Frequency-Depth ................................................................................. 2-1 Table 2.2: Design Storm Frequency with Depth Precipitation Adjustment Factors (AF) ........... 2-1 Table 2.3: Land Coverages .......................................................................................................... 2-2 Table 2.4: Bioretention Basins Discharge ................................................................................... 2-3 Table 2.6: Bioretention Basin Control Devices ........................................................................... 2-6 Table 2.7: Site Flow Results ........................................................................................................ 2-7 Table 2.8: Stormwater Conveyance Results ................................................................................ 2-8 ***** LIST OF FIGURES Page No. Figure 1-1 General Vicinity Map ............................................................................................. 1-4 Public Service Electric & Gas Company TOC-3 Burns & McDonnell

Stormwater Management Plan Revision 0 List of Abbreviations LIST OF ABBREVIATIONS Abbreviation Term/Phrase/Name BMcD Burns & McDonnell BMP Best Management Practice CF Cubic Feet CFS Cubic Feet per Second E&S Erosion and Sedimentation Control FEMA Federal Emergency Management Agency FPS Feet per Second FT Feet LF Linear Feet NAD North American Datum NAVD North American Vertical Datum NJDEP State of New Jersey Department of Environmental Protection PSE&G Public Service Electric and Gas Company R.O.W. Right-of-way WQv Water Quality Volume Public Service Electric & Gas Company i Burns & McDonnell

Stormwater Management Plan Revision 0 1.0 1.1 Site Conditions SITE CONDITIONS Site Description Public Service Electric and Gas Company (PSE&G) proposes to expand the existing West Orange 26kV switching station, located in West Orange, Essex County, New Jersey. The property is designated by West Orange as Block 155, Lot 26.01 in the City of West Orange, New Jersey which encompasses a total of 23.57 acres (refer to Figure 1-1 for the project’s general vicinity map). The site is located at the corner of Prospect Avenue and Mt Pleasant Avenue. One access point to the station will be reconstructed at the south side of the station from Mt Pleasant Avenue. The expansion of the switching station, including the fence replacement, utility connections, and driveway updates, has an overall project disturbance of approximately 3.92 acres. The site is an existing PSE&G switching station with several concrete foundations, pieces of electrical equipment, significant amounts of below-ground duct banks, a multistory brick building at the western edge of the site and a guard house located near the existing access drive. Immediately adjacent to the proposed site, to the west is a large shed, and to the north is a small parking lot and additional electrical infrastructure. The proposed station yard is to be made up of standard station gravel, various equipment foundations and new Ameristar security fence which shall replace the existing decorative fence. 1.2 Project Description Below is a list of major equipment and site improvements to be installed as part of the project: New 1 – 26kV metal enclosed switchgear ring bus with 28 feeder positions 2 – 26kV capacitor banks 3 – 26kV transformer breakers 1 – 26kV transformer neural ground resistor with fast acting ground witch perimeter fence Demolition of existing 26kV breakers, disconnects, and feeder positions 1.3 Project Stormwater Management Requirements Per N.J.A.C. 7:8, a Major Development is defined as: 1. Any development that ultimately disturbs one or more acres of land since February 2, 2004; 2. The creation of one-quarter acre or more of “regulated impervious surface” since February 2, 2004; Public Service Electric & Gas Company 1-1 Burns & McDonnell

Stormwater Management Plan Revision 0 Site Conditions 3. The creation of one-quarter acre or more of “regulated motor vehicle surface” since March 2, 2021; or 4. A combination of 2 and 3 above that totals an area greater than one-quarter acre or more. This project will disturb 3.48 acres on site and will increase impervious surfacing by 0.76 acres. Within the new impervious area, 0.22 acres of regulated motor vehicle surfacing will be added. This site is defined as a major development as it exceeds the one-acre threshold and relates to specific design criteria as follows: GROUNDWATER RECHARGE – The project is located within a Metropolitan Planning Area (PA1) and is considered an Urban Redevelopment Area, therefore it is exempt from groundwater recharge requirements under N.J.A.C. 7:8-5.4(b)2. WATER QUALITY – As stated in N.J.A.C. 7:8-5.5, since the project increases regulated motor vehicle surface by less than 0.25 acres, the project does not need to satisfy NJDEP water quality requirements. WATER QUANTITY – The project was designed to meet N.J.A.C. 7:8-5.6(b)3 by demonstrating that post-construction peak runoff rates for the current and projected 2-, 10-, and 100-year storm events, as defined in N.J.A.C. 7:8-5.7(c) and (d), do not exceed 50%, 75% and 80% of the pre-construction peak runoff rates for the respective storm events. The pre-developed watersheds associated with the current topography have been delineated, as indicated on Exhibit A. The pre-developed watersheds are reflective of the post developed watersheds that are included in the March 2012 Stormwater Management Report, prepared by TRC Engineers, Inc (See Appendix E). The post-developed watersheds associated with this project’s station upgrades, has been presented on Exhibit B. 1.4 Soils According to the Web Soil Survey developed by the United States Department of Agriculture’s (USDA) Natural Resources Conservation Service, the soil groups present on site are URBONB, Urban land, Boonton substratum, and USBONB, Urban land, Boonton substratum – Boonton complex. URBONB is previously developed land with no recorded soil type, therefore Hydrologic Soil Group D was assumed for these areas. USBONB surrounds URBONB on the site, and is classified as soil type B. However, the assumption to analyze the USBONB areas as Hydrologic Soil Group D was confirmed appropriate by the subsurface investigation.

urrounds URBONB on the site, and is classified as soil type B. However, the assumption to analyze the USBONB areas as Hydrologic Soil Group D was confirmed appropriate by the subsurface investigation. Silty Clay and Clayey Silts were found below the gravel and fill sections, Public Service Electric & Gas Company 1-2 Burns & McDonnell