44-25 Exhibit A-DPW_VI Sampling_1.17.2025.pdf

44-25 Exhibit A Matrix New World Engineering, Land Surveying and Landscape Architecture, P.C. 26 Columbia Turnpike Florham Park, NJ 07932 973.240.1800 Fax 973.240.1818 www.mnwe.com Via Email (zcarballo@westorange.org) January 17, 2025 Ms. Zayibeth Carballo, PE, PLS, PP, CME, CFM, CFS, Municipal Engineer Township of West Orange 25 Lakeside Avenue West Orange, NJ 07052 Re: PROPOSAL FOR ENVIRONMENTAL SERVICES – LONG TERM MONITORING - VAPOR INTRUSION INVESTIGATION TOWNSHIP OF WEST ORANGE DEPARTMENT OF PUBLIC WORKS (DPW) 25 LAKESIDE AVENUE BLOCK 115, LOT 16 WEST ORANGE, NEW JERSEY NJDEP SRP PI NO. 014423 MATRIX NO. P25-0037 Dear Ms. Zayibeth Carballo: Matrix New World Engineering, Land Surveying, and Landscape Architecture, P.C. (Matrix) is pleased to provide this proposal to complete long-term monitoring - vapor intrusion investigation activities and prepare a Vapor Intrusion Letter Report for submission to the New Jersey Department of Environmental Protection (NJDEP) for the Township of West Orange Department of Public Works (DPW) property, located at 25 Lakeside Avenue (Block 115, Lot 16) in the Township of West Orange (Township), New Jersey (Site). The long-term monitoring - vapor intrusion activities will be completed in compliance with the NJDEP Technical Requirements for Site Remediation (TRSR), the Site Remediation Reform Act (SRRA), the Administrative Requirements for the Remediation of Contaminated Sites (ARRCS), and the NJDEP’s Vapor Intrusion Technical Guidance. SCOPE OF WORK The scope of services and associated fees are described below. Task 1: Vapor Intrusion Investigation An initial vapor intrusion (VI) investigation was completed in 2014, and the results were presented in the 2016 Remedial Investigation Report (RIR) prepared by T&M Associates. The sampling included the collection of four sub-slab soil gas (SSSG), two indoor air (IA), and one ambient air (AA) samples for EPA TO-15 analysis. The following exceedances were identified: 1,4dichlorobenzene concentrations above the Non-Residential Indoor Air Screening Level (NRIASL) in two IA samples and trichloroethene (TCE) concentrations above the Non-Residential Soil Gas Screening Level (NRSGSL) in three SSSG samples. The concentration of TCE in sample SSAS3 was elevated to nearly an order of magnitude (10x) greater than the current NRSGSL. Based on the 2014 VI investigation results, T&M

GSL) in three SSSG samples. The concentration of TCE in sample SSAS3 was elevated to nearly an order of magnitude (10x) greater than the current NRSGSL. Based on the 2014 VI investigation results, T&M Associates recommended a long-term monitoring program for the Site which included regular building inspections and sampling of the indoor air in years 4 and 6. There was no record of this sampling being completed. F:\2025\25-0037 West Orange DPW\Proposal\LTM VI Proposal\DPW_VI Sampling_1.17.2025.docx