44-15 Proposal.pdf

MATRIXNEWORLD Enabling Progress in soil if the calculated site-specific Impact to Groundwater Soil Remediation Standard (IGWSRS) is less stringent than the NJDEP’s default IGWSSL of 0.005 mg/kg for both compounds. For AOC-2 and AOC-3, three soil borings are proposed; two for horizontal and one for vertical delineation. The soil samples will be analyzed for EPH, Category 1. Contingent analyses including naphthalene and 2- methylnapthalene (2-MN) will be analyzed on 25% of the samples where EPHs exceed 1,000 milligrams per kilogram (mg/kg). If 2-MN exceeds NJDEP’s default IGWSSL, then the sample will be analyzed using the SPLP to determine a site specific impact to groundwater soil screening level. Finally, several soil borings will be completed for the installation of temporary well points. One temporary well will be installed within the former common excavation (AOC-2 and AOC-3) as a groundwater SI is required for these former USTs. Three additional temporary wells are proposed in the anticipated downgradient direction of former TW-1 that contained VOCs, SVOCs and lead in groundwater above the GWQS. For the temporary well installed at AOC-2 and AOC-3, a groundwater sample will be collected and analyzed for VOCs and SVOCs analyses. For the remaining temporary wells installed downgradient of TW-1, groundwater samples will be collected and analyzed for VOCs. The samples will be submitted to a New Jersey-certified laboratory on a standard (two-week) turnaround. Since the temporary well points will be used to determine the placement of future monitoring wells and turbidity associated with the collection of groundwater samples collected from temporary well points could bias results high for SVOC TICs and lead groundwater samples collected from the temporary well points will not be analyzed for SVOC TICs and lead at this time. TASK 2: MONITORING WELL INSTALLATION rig. One overburden well, MW-1 will be installed in the vicinity of former temporary well, TW-1, one well, MW- 2, will be installed in the vicinity of TW-2, and the third well, MW-3, at the location of either TW-3, TW-4 or TW-5. The overburden wells will be constructed of 4-inch diameter PVC and screened from approximately 20 to 25 feet below ground surface (bgs). As noted above, additional monitoring wells may be required following the installation and sampling of temporary and monitoring wells

eened from approximately 20 to 25 feet below ground surface (bgs). As noted above, additional monitoring wells may be required following the installation and sampling of temporary and monitoring wells points. Additional monitoring well installation is not included in this scope of work. TASK 3: WELL GAUGING AND GROUNDWATER SAMPLING Approximately two weeks following the monitoring well installation activities, one round of groundwater sampling will be completed from wells MW-1, MW-2, MW-3 via low-flow purging techniques. Wells, MW-1 and MW-3, will be analyzed for VOCs and lead. MW-2 will be analyzed for VOCs and SVOCs. Water quality indicator parameters (dissolved oxygen, pH, temperature, conductivity, turbidity and ORP) will be monitored during the groundwater purging and sampling activities (Matrix Lab Certification No. 14049). One field blank and one trip blank will also be collected and analyzed for the parameters identified above. The samples will be analyzed on a standard two-week turn around. TASK 4A: SUB-SLAB SOIL GAS SAMPLING AND REPORTING, IF REQUIRED As noted above, vinyl chloride concentrations in groundwater at former temporary well, TW-1, exceed NJDEP’s GWSLs; therefore, following the installation and sampling of MW-1, a vapor intrusion investigation may be required should concentrations of vinyl chloride in groundwater remain at concentrations above the GWSLs. As part of this task, Matrix will perform a pre-sampling inspection of the fire house building approximately one week prior to the sub-slab soil gas sampling event. During the pre-sampling inspection, Matrix will select the sampling locations and coordinate with the occupants in the building. This task also includes the completion of NJDEP’s Indoor Air Sampling Form. The work will be completed in accordance with NJDEP’s March 2013 Vapor Intrusion Technical Guidance (Version 3.1). A total of seven sub-slab soil gas samples are budgeted for this project since the existing building appears to have two separate foundations and the approximate square footage of each area is 3,360 and 5,300 square feet, respectively. (OAI3-6188 - Township of West Orange - LSRP Services\ProposaRevised Soil and GW RI - December 2014\Soil and GW RI - December 2014.doc, 3 e ———