226-22 - Attachment - 25 Lakeside Avenue New Areas of Concern and CME Proposal.pdf

ASSOCIATES Mr. Leonard R. Lepore, PE August 26, 2022 Municipal Engineer/Director of Public Works Page 6 of 10 Re: Department of Public Works at 25 Lakeside Avenue ~ Site Investigation TASK 4: VAPOR INTRUSION INVESTIGATION Vapor intrusion (V1) investigation will be performed to evaluate possible impacts from vapor intrusion according to the Department’s Vapor Intrusion Guidance (VIG) Documents, revised in May 2021. Vapor intrusion occurs when volatile organic compound (VOC) vapors from contaminated soil and/or groundwater seep through cracks and holes in foundations or slabs of buildings. For the DPW office and garage building square footage, 4 SSSG, 3 IA, and 1 Ambient sample should be collected and analyzed for TO-15. Our services will include the following subtasks: 1- Indoor Air Sampling CME will evaluate the potential impacts to indoor air quality as a result of volatile organic (VO) vapors emanating from the VOC plume migrating beneath the property. Specifically, our scope of services will be to: A. Complete the Indoor Air Quality-Building Survey Form (with the help of the property owner representative) to account for potential additional sources of VOCs (not related to the discharge at Site) that may affect the proposed air sample collection from the building. B. Collect 4 indoor air samples utilizing six-liter capacity stainless steel canisters equipped with a programmed regulator suitable for sample collection over a time period of 24 hours: Cc. Perform laboratory chemical analysis for VOCs in accordance with the requirements of USEPA Method Low-Level (LL) - NJDEP LL TO-15, plus TICs, and naphthalene at an NJDEP certified laboratory. Standard chain-of-custody procedures will be implemented to track the sample. 2- Soil Gas Sampling CME will collect sub-slab soil gas samples within the slab on grade structure. To avoid the potential for cross-contamination, the soil gas sample will be collected upon conclusion of the indoor air sample (usually next day). Specifically, our scope of services will be to: A. Install 4 temporary sample points that will be utilized to collect the soil gas sample within the sampling area (basement or first floor slab). Each hole will measure approximately 3/8-inch in diameter will be advanced through the concrete slab, extending about 3 inches into the sub- slab soil. Following this, the top 1-inch of the hole will

Each hole will measure approximately 3/8-inch in diameter will be advanced through the concrete slab, extending about 3 inches into the sub- slab soil. Following this, the top 1-inch of the hole will be over-drilled to a diameter of about |