Township Council Meeting — Packet

ft i Cc ASSOCIATES Mr. John Gross April 14, 2023 Township Business Administrator‘CFO. Page 5 of 8 Re: Department of Public Works at 25 Lakeside Avenue -- Remedial Investigation feet and one well will be constructed as a double-cased deep well and will be installed to a depth of 40-45 feet below ground surface (bgs). Based on the regional geology at the site vicinity, it is expected that the subsurface materials encountered will consist primarily of shale bedrock. 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 weil construction. TASK 3; GROUNDWATER SAMPLING Two (2) rounds of groundwater samples will be collected from all monitoring wells to delineate the impacted groundwater and evaluate trends and seasonal fluctuations in contaminant concentrations and provide a baseline dataset for further remedial investigation, if needed. + Two rounds of groundwater samples will be collected using existing wells and proposed monitoring wells MW-4 through MW-9. 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 Target Compound List (TCL) VOCs and TCL semi volatile organic compounds (SVOCs) and TAL Metals in accordance with the TRSR and NJDEP guidance documents. Trip blank samples will accompany the groundwater sample(s) and will be analyzed for TCL VOCs and TBA. One (1) field blank sample will also be collected each day of field activities. The blanks will be handled and transported in the same manner and analyzed for the same parameters

for TCL VOCs and TBA. One (1) field blank sample will also be collected each day of field activities. The blanks will be handled and transported in the same manner and analyzed for the same parameters as the samples collected that day. If groundwater contamination is delineated, additional groundwater sampling may be performed to evaluate compliance with remediation standards and determine if natural attenuation and CEA can be used as the groundwater remedial action at the Site; costs of the additional sampling are not included in this proposal. If groundwater contamination is not delineated, additional monitoring wells and sampling will be required; costs is not included in this proposal.