2026 05 Storm Water Management Report rcd 5 6 2026

STORMWATER COLLECTION SYSTEM CALCULATIONS (PIPE SIZING)

NOTES: Project: Mavis Tire Supply, LLC Computed By: AJH 1) Design method used is Rational Method, unless otherwise noted. Job #: 1956-24-04187 Checked By: 2) Refer to Weighted Runoff Coefficient table Location: West Orange Township Date: 5/5/2026 for calculation of incremental areas and C values Design Storm: 25 yr SUBCATCHMENT TIME OF PIPE SECTION INCREMENTAL CUMULATIVE I PEAK RUNOFF PIPING INPUT PIPING DATA AREA CONCENTRATION Tc to Tc in Q cum. Pipe Pipe Final Tc Q to Inlet Dia. Length Man. Slope FROM TO Area (Acres) "C" A x C Ac A x C (acres) Inlet Pipe (In/Hr) for Pipe Capacity Velocity (min) (CFS) (In) (Ft) "n" (ft/ft) (min) (min.) (CFS) (cfs) (fps) EXIST. BUILDING EXIST. ROUND INLET 0.150 0.98 0.150 0.150 6.00 0.11 6.00 7.70 1.16 1.16 6 40.0 0.014 0.0500 1.16 5.91 EXIST. ROUND INLET PROP. MH #3 0.100

0 0.150 6.00 0.11 6.00 7.70 1.16 1.16 6 40.0 0.014 0.0500 1.16 5.91 EXIST. ROUND INLET PROP. MH #3 0.100 0.95 0.100 0.250 6.00 0.06 6.11 7.70 0.77 1.93 12 26.0 0.013 0.0255 5.69 7.25 PROP. INLET #7 PROP. INLET #6 0.082 0.88 0.070 0.070 6.00 0.32 6.00 7.70 0.54 0.54 15 64.0 0.012 0.0035 4.14 3.38 PROP. INLET #6 PROP. MH #3 0.074 0.89 0.070 0.140 6.00 0.32 6.32 7.70 0.54 1.08 15 64.0 0.012 0.0035 4.14 3.38 PROP. MH #3 PROP. OCS #2 0.000 0.00 0.000 0.390 6.00 0.33 6.64 7.59 0.00 2.96 15 67.0 0.012 0.0035 4.14 3.38 PROP. OCS #2 EXIST. A-INLET 0.140 0.74 0.100 0.490 6.00 0.07 6.97 7.59 0.76 3.72 15 15.0 0.012 0.0035 4.14 3.38 PROP. YARD INLET EXIST. A-INLET 0.002 0.35 0.000 0.000 6.00 0.04 6.00 7.70 0.00 0.00 12 7.0 0.013 0.0050 2.52 3.21 EXIST. A-INLET EXIST. MANHOLE 0.006 0.35 0.000 0.490 6.00 0.24 7.04 7.48 0.00 3.66 15 97.0 0.012 0.0143 8.37 6.82 PROP. UG BASIN OCS EXIST. MANHOLE 0.142 0.95 0.130 0.130 6.00 0.07 6.00 7.70 1.00 1.00 15 15.0 0.012 0.0035 4.14 3.38

BASIN DRAIN TIME CALCULATIONS

Bioretention Basin Drain time Calculations Project: Proposed Mavis Tire Supply Computed By: AJH Job #: 1956-24-04187 Checked By: Location: West Orange, New Jersey Date: 4/28/2026 Revised: Basin Name: Bioretention Basin with Underdrains Volume of Runoff Below First Orifice = 372 cubic feet Surface Area of Bioretention Basin Soil Bed = 323 square feet Effective Depth of Runoff to be Infiltrated = Volume of Runoff Below First Orifice / Surface Area of Soil Bed = 1.15 feet = 13.82 inches Permeability Rate of Soil Bed = 1 inches per hour Design Recharge Rate * = 0.5 inches per hour Effective Depth of Runoff to be Infiltrated / Design Recharge Rate = Time to Empty Basin = 27.64 hours** *Note : Factor of Safety of 2 is applied to the Field Tested Recharge Rate to establish the Design Recharge Rate **Note : Time to Empty Basin must be less than 72 hours. Therefore; Drain time is less than 72 Hours, therefore, design is acceptable

RIPRAP STABILITY CALCULATIONS

0123467829  288 38 8 349  18989  !"" #8$ %% &' ($%$! % ))) *288 17 +,-  ./01123 401035676 8484849:;<=>=?>:;?4@:A@BA 1BC= 9:;<=>=?>:;?4@:A@BA D:EFGB<H= IJK .GB??=L46L;A= IJM .GB??=L49;>>;C4N:O>G P 3=Q>46:O=46L;A= R @:HG>46:O=46L;A= R 3;S4TL;S43:?=< @=>B<O=?F=4.LBEE .4KUMP4:? V=H=>B>:;?4WXA= 6;O4T;<C=< V=H=>B>:;?4D=?E:>X 2YF=LL=?>484Z[\ 6;:L4WXA= 6:L>43;BC4]6^_ 1 `9a2a ijklm nmkoj pqlojkrsm tmuvoqwx yvrzku |k}}q}sl~y imrzqllqum kuo‚ukwmƒ €k„mwx nmzkr†l €wk{um pm{wj €jmkr~€wrmll €jmkr~€wrmll kowvr ikwwmr} 1 `9a2a 329*43 !c %dc3e dc3 "% %fec3% %fec3% "$$ #6gh+  b 8*8338 FOS > 2 ; OK VELOCITY EXCEEDS 2 FT/S WHICH JUSTIFIES NEED FOR RIPRAP Q = CIA = 1 x 6 iph x 0.10 Ac. = 0.6 cfs

RESULTS OF TEST PIT EXCAVATION AND INFILTRATION TESTING – PREPARED BY ECS

Geotechnical  Construction Materials  Environmental  Facilities January 29, 2025 Ms. Rachael Dickinson Pre-Construction Project Manager Mavis Tire Supply, LLC 200 Summit Lake Drive, Suite 350 Valhalla, NY 10595 ECS Project Number: 44:2100-A Reference: Addendum No. 1 - Results of Test Pit Excavation and Infiltration Testing Mavis Store #2296 460 Prospect Avenue, West Orange, New Jersey Dear Ms. Dickinson: ECS Mid-Atlantic, LLC (ECS) is pleased to present the interpreted subsurface profiles and results from the test pits excavations and infiltration testing completed at the referenced project site location. The work described herein was performed to supplement the previous subsurface exploration executed under ECS project No. 44:2100. The purpose of the explorations was:  To perform infiltration testing, the results of which will be considered in the design of the potential stormwater management (SWM) facilities.  To further evaluate the existing fill materials and to better understand the make-up and depth of these materials to further determine suitability for support of the foundations and/or if undercuts will be necessary. Our services were provided in general accordance with the scope provided to Mavis in email correspondence dated December 12, 2024 (ECS Proposal No. 44:2237-GP), which was authorized via email on December 16, 2024. PROJECT UNDERSTANDING The project site is located at 460 Prospect Avenue, West Orange, Essex County, New Jersey. In discussions with Mavis, further evaluation of the fill material within the footprint of the proposed retail auto service building was required. In addition, as understood from information provided by Mavis, a stormwater management (SWM) facility is proposed as part of the overall site development. Limited details regarding the SWM facility were available at the time of testing and the infiltration testing locations were selected in the general location of the SWM facility as approved by Mavis. 2

the SWM facility were available at the time of testing and the infiltration testing locations were selected in the general location of the SWM facility as approved by Mavis. 2 EXECUTIVE DRIVE, SUITE 11, MOORESTOWN, NJ 08057  T: (609) 832-3910  F: (484) 840-5586 ECS Florida, LLC  ECS Mid-Atlantic, LLC  ECS Midwest, LLC  ECS Pacific, Inc.  ECS Southeast, LLC  ECS Southwest, LLP ECS New York Engineering, PLLC – An Associate of ECS Group of Companies  www.ecslimited.com “ONE FIRM. ONE MISSION.”