Groundwater Characterization and Remediation

Weston was contracted by New Hampshire Department of Environmental Services to address the release of chlorinated VOCs to the vadose zone, overburden groundwater, and bedrock groundwater from a former tool and die operation. Since 2007, Weston has managed an RI, FS, incidental remediation services in support of remedial actions, construction phase engineering design, and optimization of O&M of a groundwater pump and treat system. Work has included geospatial groundwater modeling using EarthVision® software, an energy efficiency and manpower evaluation of the treatment plant, and an effectiveness assessment of an existing soil vapor extraction system. Additional sources of residual soil contamination that were prolonging groundwater remediation were identified and treated using ex situ chemical oxidation with ozone. These treatment technologies shortened cleanup time by 10 years and reduced more than 1,000 ib. of chlorinated VOCs. Weston’s pump and treat system reduced annual O&M and monitoring costs by more than 50%, while increasing reliability and the overall run-time, which has exceeded 99% since Weston implemented updates. The accelerated cleanup of the site will improve water quality and is critical to restoring nearby properties to beneficial use.