100-25 Exhibit B-Additional wells and sampling.pdf

Ms. Zayibeth Carballo, PE,PLS,PP,CME,CFM,CFS Director, Municipal Engineer March 11, 2025 Re: Department of Public Works at 25 Lakeside Avenue – Change Order Page 2 P:\I00 CME7\West Orange\DPW 25 Lakeside Ave\Budget - Proposal- DPW FILE\March 2023 RI Proposal\Change Order - Additional wells and sampling - West Orange DPW - 3-11-2025.docx Additional two monitoring wells will be installed, and a groundwater sampling at selected 10 monitoring wells will be conducted and analyzed for Metals to determine the extent of the AOC discharge impacts. CME will retain a licensed driller to install the monitoring wells with 2-inch diameter PVC; the wells will be constructed to a depth of approximately (20) feet below ground surface (bgs). The depths and locations of the monitoring wells will be determined based on the findings of the investigations conducted to date to delineate the extent of contaminants identified during the initial sampling event. The wells will be completed with a flush-mount cover. Drill cuttings will be placed in drums and properly disposed off-site at a licensed facility, and development water will be drummed for off-site disposal or properly treated prior to on- site discharge. A professional licensed surveyor will survey the monitoring wells. Well logs and Form A and Form B will be prepared to properly document the well construction. One round of groundwater samples will be collected from ten (10) selected monitoring wells to delineate the impacted groundwater and provide a baseline dataset for further remedial investigation, if needed. Sampling will be performed in accordance with USEPA Low Flow Sampling Procedures (March 1998). Water levels will be measured in all monitoring wells to confirm the groundwater flow direction. Water quality parameters will be directly measured in the field including conductivity, pH, temperature, redox potential, salinity, and dissolved oxygen (DO). All groundwater samples will be submitted for laboratory analysis for TAL Metals in accordance with the TRSR and NJDEP guidance documents. Our estimated cost to complete the additional required services is $19,700. Task Description Cost 1 Monitoring Wells Installation $ 10,200 2 Groundwater Sampling $ 9,500 We appreciate your consideration of the above and would be happy to answer any questions regarding this request. Respectfully submitted, CME

Wells Installation $ 10,200 2 Groundwater Sampling $ 9,500 We appreciate your consideration of the above and would be happy to answer any questions regarding this request. Respectfully submitted, CME Associates _________________________________ Behram Turan, P.E., LSRP Senior Vice President cc: Michael McClelland, P.E., P.P. - CME Associates