J_2024 05 09_West Orange Stormwater Management Plan

August 8, 2022 File No. 26.0092704.00 PSE&G – West Orange, NJ Page 12 Proactive by Design It is our opinion that foundations designed and installed in accordance with our recommendations would experience post-construction settlements of 3/4 of 1 inch, or less. Seismic Considerations: Based on the regional geology, the subsurface conditions encountered in the explorations at the site and published geologic information, it is our opinion that the foundations for the proposed improvements can be designed using a Site Class “C” as determined by the International Building Code 2018, New Jersey Edition. Concrete Slab Design Criteria: Following the previously described site preparation procedures, any atgrade concrete slabs could be supported by the controlled compacted fill installed atop the natural soils. Due to potential variations within the existing fill materials, the existing fill would not be suitable for direct slab support and should be removed and replaced as necessary. We recommend that a minimum 6-inch-thick layer of porous fill consisting of clean 3/4-inch stone be placed beneath the slabs to provide a capillary break between the subgrade soils and the bottom of the concrete, and to help provide a stable working base during construction. A subgrade modulus of 150 pounds per cubic inch (pci) would be appropriate for design of slabs established atop the native clayey and silty soils, while a modulus of 200 pci would be appropriate for design of slabs established atop properly placed granular controlled compacted fill. We estimate that maximum post-construction settlements of lightly loaded slabs will be less than 1/4 of 1 inch. More heavily loaded transformer pads (if any are proposed) could experience greater total settlements which are estimated to be about 1 inch or less but could be confirmed when loads are available. An Equal Opportunity Employer M/F/V/H

August 8, 2022 File No. 26.0092704.00 PSE&G – West Orange, NJ Page 13 Proactive by Design Lateral Earth Pressures: If required, excavation support systems, below grade structures or site retaining walls should be designed to resist lateral earth pressures imposed by the adjacent soils, as well as surcharge loads due to adjacent equipment, traffic, floor slabs or foundation loads, etc. We estimate that the following soil parameters could be used to design these systems: Total Active Earth Unit Weight (pcf) Angle of Internal Friction (degrees) Cohesion (psf) Existing sandy and clayey fill materials 120 30 0 0.333 Clean ¾” crushed stone backfill 105 38 0 0.238 Natural silty and clayey sands or imported granular controlled compacted fill 125 34 0 Natural sandy silts and clays 120 26 2,000 Soil Type Pressure Coefficient (Ka) 0.282 0.390 We do not recommend that any silty or clayey soil be used as backfill adjacent to below-grade walls as they are relatively poorly draining and may impose higher lateral pressures. Excavated sands, silty sand or imported granular materials as previously specified would be better suited for this use. Stormwater Management Design: As part of our work, we were requested to perform three test pits and permeability tests. The logs of the test pits (TP-101 through TP-103) have been provided in USDA format for stormwater design purposes. In addition, single ring field infiltration tests were initiated at An Equal Opportunity Employer M/F/V/H

August 8, 2022 File No. 26.0092704.00 PSE&G – West Orange, NJ Page 14 Proactive by Design each test pit location within the existing fill materials at about 3 to 3.3-feet below the ground surface. At each location, the test failed to drain during the presoak period resulting in failed tests. Laboratory tube permeameter permeability tests were also performed on tube samples obtained from the test pits. The tube permeameter tests indicate that the clay loam and silt loam fill materials were relatively impermeable, with occasional permeable loam fill layers. The single ring infiltration and tube permeameter tests are summarized on the individual test pit logs. Chemical Testing: Three samples of the near surface soils were submitted to an NJDEP certified laboratory to determine pH, sulfates, chloride ion, electrical resistivity, redox potential, and sulfides. The test results pH are summarized on Plate 9. Based on American Concrete Institute ACI 318 guidelines, sulfate levels of less than 1,000 parts per million (ppm) indicate a negligible exposure for corrosion of concrete, and ACI recommends the use of Type I cement. The sulfate test results ranged from 34.9 to 90.2 ppm. The USDA guidelines indicate a pH of less than 5.5 for sandy soils or 5.0 for fine-grained soils are considered to have a high risk of corrosion potential for concrete. The pH test result ranged from 3.44 to 5.58. Therefore, based on the results of the tests, we would recommend that Type II cement be used. In order to evaluate the risk of uncoated ductile iron pipe to corrosion, the AWWA takes five parameters into consideration including electrical resistivity, pH, redox potential, sulfides and moisture content. Each category is assigned a point value, and if the total points are 10 or higher, that indicates the soil is corrosive to ductile iron pipe and protection is needed. The samples tested in SBH-1 and SBH-2 resulted An Equal Opportunity Employer M/F/V/H

August 8, 2022 File No. 26.0092704.00 PSE&G – West Orange, NJ Page 15 Proactive by Design in a total of one point for each sample, while Boring SBH-5 resulted in a total of 5 points. Therefore, the testing indicates the soils have a low potential for corrosion to ductile iron. Please contact us if you have any questions regarding this report. The following Plates and Appendices are attached and complete this report: Plate 1 - Site Location Map Plate 2 - Plot Plan Plate 3A through 3E - Test Borings Logs Plate 4A through 4C - Test Pits Logs Plate 5 - Unified Soil Classification System Plate 6 - USDA Soil Textural Triangle Plate 7 – Engineering Rock Classification Chart Plates 8A and 8B - Gradation Curves Plate 9 - Summary of Chemical and Soil Box Resistivity Tests Plate 10 - Suggested Foundation Overexcavation Detail Appendix I - Geotherm Test Results Appendix II – Rock Core Photographs Appendix III – Rock Core Compression Test Results Appendix IV - Limitations Respectfully submitted, GZA GeoEnvironmental, Inc. Christopher D. McLaughlin, P.E. Senior Project Manager Robert E. Schwankert, P.E. Consultant/Reviewer CDM:MRD/cdm (1 copy submitted via email) An Equal Opportunity Employer M/F/V/H Mark R. Denno, P.E. Principal

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TEST BORING LOG EXPLORATION NO.: SBH-1 SHEET: 1 of 1 PROJECT NO: 26.0092704.00 REVIEWED BY: Chris McLaughlin Engineers and Scientists West Orange Logged By: Juan Matallana Type of Rig: Track Rig Boring Location: See Plan Drilling Co.: Craig Test Borings, Inc. Driller: Bryan Rig Model: CME 55LC Drilling Method: Mud Rotary Ground Surface Elev. (ft.): 602.5 Date Start - Finish: 6/29/2022 - 6/29/2022 Hammer Type: Automatic Hammer Auger or Casing O.D./I.D Dia (in.): 6 Rock Core Size: 2 Depth (ft) No. S1 S2 Depth (ft.) Sample Blows (per 6 in.) 1.5 * 3-5 14 19 19 38 5 10 SPT Value 38 5-7 33 27 23 24 50 S4 7-9 44 100/3" 100+ S5 9-11 S6 11-12.1 15 Groundwater Depth (ft.) Time Water Depth 6/29/22 Sample Description and Identification 100+ Brown clayey silt, and fine to medium sand, little fine gravel (very moist)(hard) ML - grading with some fine to coarse gravel, cobbles and boulders ROCK CORE RUN NO. 2: 20' to 25' REC = 100% RQD = 68% 25 Water Depth Content (ft) (%) 19.3 18.5 5 10 100+ Gray fractured basalt, fair quality, very close to close joint spacing ROCK CORE RUN NO. 1: 15' to 20' REC = 95% RQD = 53% 20 Stab. Time NR 10" Crushed stone Fill - Reddish brown silt, and fine to coarse sand, trace fine gravel (very moist)(medium dense) S3 37 75 134 120 30 75 100/2" Symbol Hammer Fall (in.): 30 Coring Time (min/ft) Hammer Weight (lb.): 140 Date Final Boring Depth (ft.): 25 End of exploration at 25 feet. 15 20 25 35 * - Hand dug to 3' REMARKS 2 - MTA BORING LOG WITH CORES; 8/8/2022; 11:08:19 AM 30 See Log Key for exploration of sample description and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. Plate No.: 3A Remark PSE&G GZA GeoEnvironmental, Inc. *

TEST BORING LOG EXPLORATION NO.: SBH-2 SHEET: 1 of 1 PROJECT NO: 26.0092704.00 REVIEWED BY: Chris McLaughlin Engineers and Scientists West Orange Logged By: Juan Matallana Type of Rig: Track Rig Boring Location: See Plan Drilling Co.: Craig Test Borings, Inc. Driller: Bryan Rig Model: CME 55LC Drilling Method: Mud Rotary Ground Surface Elev. (ft.): 602.5 Date Start - Finish: 6/29/2022 - 6/29/2022 Hammer Type: Automatic Hammer Auger or Casing O.D./I.D Dia (in.): 6 Rock Core Size: 2 Depth (ft) No. S1 5 Depth (ft.) Sample Blows (per 6 in.) SPT Value 1 * S2 2-4 4 4 3 3 7 S3 4-6 5 5 5 6 10 S4 6-8 8 9 10 16 19 S5 8-10 20 5 7 10 12 10-12 2 2 3 4 5 10 S6 Symbol Hammer Fall (in.): 30 Coring Time (min/ft) Hammer Weight (lb.): 140 CL Date Final Boring Depth (ft.): 30 Groundwater Depth (ft.) Time Water Depth Sample Description and Identification 12" Crushed stone Fill - Reddish brown silt, and fine to medium sand, trace fine gravel (moist) Buried Topsoil - Very dark brown silty clay, trace fine sand (slight organic odor) (wet)(medium) Gray silty clay, little fine sand (very moist)(stiff) Stab. Time Water Depth Content (ft) (%) * 23.9 5 19.4 Brown silty clay, some fine to coarse sand, trace fine gravel (very moist)(very stiff) 10 - grading (wet)(medium) CL 15 S7 15-16.2 7 16 100/2" - sampler refusal atop cobbles/boulders 100+ 20 5.8 6.5 7.1 8.0 14.2 25 4.2 4.1 5.8 5.1 ROCK CORE RUN NO. 2: 25' to 30' REC = 100% RQD = 58% - grading to fair quality, close joint spacing 4.3 30 End of exploration at 30 feet. 15 20 25 30 35 * - Hand dug to 2.5' REMARKS 2 - MTA BORING LOG WITH CORES; 8/8/2022; 11:08:20 AM Gray fractured basalt, very poor quality, very close joint spacing ROCK CORE RUN NO. 1: 20' to 25' REC = 85% RQD = 13% See Log Key for exploration of sample description and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. Remark PSE&G GZA GeoEnvironmental, Inc. Plate No.: 3B

TEST BORING LOG West Orange Logged By: Juan Matallana Type of Rig: Track Rig Boring Location: See Plan Drilling Co.: Craig Test Borings, Inc. Driller: Bryan Rig Model: CME 55LC Drilling Method: Mud Rotary Ground Surface Elev. (ft.): 602.5 Date Start - Finish: 6/28/2022 - 6/28/2022 Hammer Type: Automatic Hammer Auger or Casing O.D./I.D Dia (in.): 6 Rock Core Size: 2 Depth (ft) No. 5 Depth (ft.) Sample Blows (per 6 in.) SPT Value 1 * S2 3 * S3 4-6 4 3 3 3 6 S4 6-8 4 3 3 3 6 S5 8-10 9 9 9 7 18 S6 10-12 11 9 8 8 17 20 S7 15-17 13 7 10 8 S8 20-20.2 100/2" Fill - Reddish brown clayey silt, and fine to medium sand, trace fine gravel (wet)(medium) 17 SM 9.8 12.0 9.6 9.3 11.3 11.1 12.0 12.5 REMARKS - sampler refusal atop cobbles/boulders Gray fractured basalt, poor quality, very close joint spacing ROCK CORE RUN NO. 1: 25' to 30' REC = 100% RQD = 48% ROCK CORE RUN NO. 2: 30' to 35' REC = 28% RQD = 0% - grading to very poor quality 10.7 * - Hand dug to 4' * - Hand dug to 4' 14.5 5 Buried Topsoil - Dark gray silty clay, and fine to medium sand, trace fine gravel, trace organics (slight organic odor) (very moist)(medium) 10 Reddish brown silty clay, and fine to medium sand, little fine to coarse gravel (moist to wet)(very stiff) Reddish brown fine to medium sand, and clayey silt (wet)(medium dense) 12.0 35 Water Depth Content (ft) (%) 20.8 21.7 25 30 Sample Description and Identification Stab. Time * * CL 15 Groundwater Depth (ft.) Time Water Depth 11" Topsoil Fill - Reddish brown silt, and fine to medium sand, trace fine gravel, trace roots (moist) S1 10 Symbol Hammer Fall (in.): 30 Coring Time (min/ft) Hammer Weight (lb.): 140 Date Final Boring Depth (ft.): 35 Remark Engineers and Scientists 2 - MTA BORING LOG WITH CORES; 8/8/2022; 11:08:21 AM EXPLORATION NO.: SBH-3 SHEET: 1 of 1 PROJECT NO: 26.0092704.00 REVIEWED BY: Chris McLaughlin PSE&G GZA GeoEnvironmental, Inc. 17.2 15 20 25 30 35 End of exploration at 35 feet. See Log Key for exploration of sample description and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the

ctual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. Plate No.: 3C