Lewis Consulting Group (LCG) was retained by a private development company to complete a subsurface Vapor Intrusion (VI) Investigation for a privately owned property located in Lakewood, New Jersey. Upon review of owner supplied documents and NJDEP online databases, LCG identified an existing impacted groundwater plume situated immediately adjacent to the south within approximately forty-two feet of the known extent of the groundwater contamination area (CKE) encroaching on the southern portion of the site. Due to the proposed residential development activities and the proximity of the existing CKE plume, a VI investigation was recommended to confirm that volatile chemicals have not migrated into on-site subsurface soils.
LCG divided the area of investigation into four (4) quadrants. Soil-gas samples were collected from the basement areas associated with the proposed residential structures. LCG advanced four (4) soil vapor points to a depth of ten (10) feet below soil grade to collect a total of four (4) soil-gas samples and one (1) ambient air sample. Samples were subsequently analyzed by a certified New Jersey laboratory for TO-115. Results indicated the presence of contaminants above the NJDEP's Non-Residential Indoor Air Screening Level (NRIASL) and Residential Indoor Air Screening Level (RIASL). Therefore, further investigation was recommended to delineate on-site soil vapor contamination and effectively select the appropriate mitigation strategy. All activities were conducted in accordance with NJDEP's Technical Requirements for Site Remediation (N.J.A.C. 7:26E).
A comprehensive VI Investigation Report was prepared for the client for submission to its lenders. The VI Investigation Report contained a description of investigative activities, data tables comparing the results of the soil vapor samples with NJDEP standards, and figures depicting applicable site plans.