Geotech Report 02 12 2024

SOR CONSULTING ENGINEERS, INC. Garden Homes/West Essex Highlands, Inc. Report No. 24-C-02 Subsurface Stormwater Management System Page 7 West Orange, NJ approximately +602 to +604 feet. The subsurface conditions revealed in the test pits performed for this study encountered 8 to 18 inches of topsoil/vegetation. The topsoil was underlain by silty gravelly sand and extended to the maximum depth explored, 10 feet. Groundwater or seasonal high groundwater was not encountered at the maximum depths explored. Laboratory tube permeameter testing performed on the silty gravelly sand stratum (loam material) resulted in permeability rates of 0.61 to 0.94 inches per hour (K2 soils). We recommend that the stormwater management system be hydraulically connected to these materials found beneath the topsoil. The system should be designed in accordance with the NJDEP Stormwater BMP Manual based on the specific measured permeability rates in each area. We also recommend that the infiltrative surface be covered with a geotextile filter fabric or properly graded soil/aggregate filter material to provide a unform separation layer and infiltrative surface to minimize the transmission of fines and possible soil clogging. Basin (TP-33 through TP-38): The area is partially wooded. Topographic data provided to us indicates that the ground surface elevations range from +578 to +594 feet. The subsurface conditions revealed in the test pits performed for this study encountered 4 to 10 inches of topsoil/vegetation. The topsoil was underlain by clayey soil to depths of 1.5 to 3 feet at TP-33, 34, and 35. The topsoil and clayey soil was underlain by silty gravelly sand and extended to maximum depths explored. At TP-37 and 38 bedrock was encountered at depths of 5 to 6 feet below surface. Groundwater was only encountered at Test Pits 33, 34, and 36 at depths of 9 to 11 feet below surface. Laboratory tube permeameter testing performed on the silty gravelly sand (loam material) resulted in permeability rates of 0.45 to 0.82 inches per hour (K1 to K2 soils). We recommend that the stormwater management system be hydraulically connected to these materials found below the topsoil or clayey soil. The system should be designed in accordance with the NJDEP Stormwater BMP Manual based on the specific measured permeability rates in each area. We recommend that the infiltrative surface be covered

. The system should be designed in accordance with the NJDEP Stormwater BMP Manual based on the specific measured permeability rates in each area. We recommend that the infiltrative surface be covered with a geotextile filter fabric or properly graded soil/aggregate filter

SOR CONSULTING ENGINEERS, INC. Garden Homes/West Essex Highlands, Inc. Report No. 24-C-02 Subsurface Stormwater Management System Page 8 West Orange, NJ material to provide a uniform separation layer and infiltrative surface to minimize the transmission of fines and possible soil clogging. Basin (TP-39): The area is presently open land. The topographic data provided to us indicates that the ground surface elevations is approximately +537 feet. The preliminary bottom of basin elevation is set at +530 feet. The subsurface conditions revealed in the test pits performed for this study encountered 6 inches of topsoil. The topsoil was underlain by clayey soil to a depth of 3 feet below surface. The clayey soil was underlain by reddish brown silty gravelly sand (loam material) and extended to the maximum depth explored, 10 feet. Groundwater was encountered at a depth of 9 feet below surface. Laboratory tube permeameter testing performed on the loam material resulted in permeability rate of 0.81 inches per hour (K2 soils). We recommend that the stormwater management system be hydraulically connected to these materials found below the depth of 3 feet. The system should be designed in accordance with the NJDEP Stormwater BMP Manual based on the specific measured permeability rates in each area. We also recommend that the infiltrative surface be covered with a geotextile filter fabric or properly graded soil/aggregate filter material to provide a uniform separation layer and infiltrative surface to minimize the transmission of fines and possible soil clogging. RECOMMENDED SERVICES It is recommended that Sor Consulting Engineers be provided the opportunity for a general review of the final design and specifications to assure that the stormwater management system recommendations are properly interpreted and implemented in the construction documents. We also recommend that controlled compacted fill and backfill operations as well as stormwater management system subgrades be observed by a geotechnical engineer from our firm. This is to ensure compliance with the recommendations contained herein and to address any changes in the subsurface conditions that were not disclosed by the test pits.

SOR CONSULTING ENGINEERS, INC. Garden Homes/West Essex Highlands, Inc. Report No. 24-C-02 Subsurface Stormwater Management System Page 9 West Orange, NJ Sor Consulting Engineers appreciates the opportunity to be of assistance with this project. Should there be any questions concerning the information provided herein, please do not hesitate to contact us. The following appendices are attached and complete this report: Appendix |: Exploration Location Plan Appendix Il: Test Pit Logs TP-1 through TP-39 Burmeister and USDA Soil Classification System Appendix III: Laboratory Soil Test Results Appendix IV: Limitations Respectfully submitted, SOR CONSULTING ENGINEERS, INC. Atilla Sencar, P.E. Senior Engineer AS/gs cc: Anderson Consulting Service, LLC Attn: Paul Anderson, P.E., P.P., CME E-Mail: pandersonpe@gmail.com

APPENDIX | EXPLORATION LOCATION PLAN

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APPENDIX I TEST PIT LOGS TP-1 THROUGH TP-39 BURMEISTER AND USDA SOIL CLASSIFICATION SYSTEM

SOR CONSULTING TEST PIT LOG TEST PIT NO. TP-1 ENGINEERS, INC. CLIENT: Garden Homes/West Essex Highlands, Inc. (ase Tee |WATER LEVEL 8-0" PROJECT: Stormwater Management System DATE 4119/2024 LOCATION ; West Orange, New Jersey [JOB NO. 24-C-02 IREPORT NO. 24-0 DEPTH) pensity | MOISTURE GROUND SURFACE REMARKS FTopsoiiVegetation 1 10" Medium Moist | Yellowish brown coarse to fine Sand, some Clayey Silt, 2 | Compact some coarse to fine Gravel (Silt Loarn) 3 4 ae Medium Dark yellowish brown coarse to fine Sand, and Silt, some coarse 8 | Compact Moist to fine Gravel, with cobbles (Loam) Permeability @6' K=0.26in/hr (K1) 6 7 Water Seepage @ 8° 8 9 Medium Compact Wet 10 ahs Test Pit Completed at 17'-6" 12 13 14 15 16 AT 18 19 20 EXCAVATOR : D. Willis Excavating EQUIPMENT : STL REPRESENTATIVI jackhoe ‘Sencar

SOR CONSULTING TEST PIT L' TESTPITNO. TP-2 ENGINEERS, INC. OG ELIENT: Garden Homes/West Essex Fightands, Inc. (ase eT [WATER LEVEL 0" PROJECT: Stormwater Management System DATE Tepp024 LOCATION: West Orange, New Jersey [05 NO. 2002 IREPORT NO. 24-C-02 DEPTH) pensity | moisture GROUND SURFACE REMARKS FFopeoil Vegetation 4 12" Firm Moist _| Yellowish brown coarse to fine Sand, and Clayey Sit (Silt Loam) 2 3 4 5 Dense Moist zi Reddish brown coarse to fine Sand, some Sil, and coarse 6 to fine Gravel, cobbles (Loam) Permeabilty @6" K=1.05in/hr (K2) 7 8 8 Water Seepage @ 9! Wet 10 "1 12 ‘Test Pit Completed at 12'-0" 13 14 15 16 47 18 19 20 EXCAVATOR : D. Willis Excavating EQUIPMENT : ‘STL REPRESENTATIVE

SOR CONSULTING ENGINEERS, INC. TEST PIT LOG TEST PIT NO. TP-3 CLIENT : Garden Homes/West Essex Highlands, Inc. [ese WATER LEVEL 7-0" PROJECT: Stormwater Management System LOCATION : West Orange, New Jersey DEPTH FT. DENSITY MOISTURE GROUND SURFACE. REMARKS a Firm Medium 5 Dense 10 4 Moist Moist Wet FTopsoll/Vegetation 12" Yellowish brown coarse to fine Sand, and Clayey Silt, little coarse to fine Gravel (Silt Loam) Reddish brown coarse to fine Sand, some Silt, some coarse to fine Gravel, cobbles (Sandy Loam) Permeability @3° K=0.15in/hr (KO) Permeability @5' K=1.43in/hr (K2) Water Seepage @ 7' 12 13 4 20 Test Pit Completed at 11-0" EXCAVATOR : D. Wilis Excavating EQUIPMENT : Backhoe: ‘STL REPRESENTATIVE : A Sencar