Naval Facilities Engineering Command Mid-Atlantic, 73 pp, 2019

Wastes containing VOCs, SVOCs, PCBs, Cr, and Cd were disposed in drainage sumps, dry wells, and on the ground surface at Site 1 of the former the Naval Weapons Industrial Reserve Plant (NWIRP). The original remedy was an air sparging/soil vapor extraction system (SVE) that operated from 1997-2002 and removed >95% of VOCs in groundwater. A soil vapor investigation conducted in 2008 found TCE (250 µg/m³ ) and PCE (1,000 µg/m³) that exceeded state criteria at the eastern site boundary. An onsite SVE containment system (SVECS) was installed to capture the vapor and prevent further offsite migration. The SVECS has 12 SVE wells along the boundary, 18 soil vapor monitoring points, and soil vapor treatment consisting of a moisture separator, two SVE blowers, and a 5,000 lb vapor-phase granular activated carbon unit to remove VOCs from the offgas. The system runs 24 h/day, 7 days/week, except for maintenance and adjustment periods. Analytical results of vapor samples collected annually from these locations and the soil vapor pressure readings are used to further evaluate the SVECS operation and the potential for vapor intrusion. As of the third Quarter of 2019, total concentrations remain one to two orders of magnitude below baseline concentrations. https://www.navfac.navy.mil/niris/MID_ATLANTIC/BETHPAGE_NWIRP/N90845_002913.pdf
More information on the NWIRP site: https://www.navfac.navy.mil/products_and_services/ev/products_and_services/env_restoration/installation_map/navfac_atlantic/midlant/nwirp_bethpage/site_descriptions/site1_former_drum_marshalling_area.html