MGP Site Investigation, Risk Assessment, Remedial Design, and Implementation
The Elizabeth City site includes an onsite portion where the MGP was located, downgradient wetlands, and a creek. The Ecological Risk Assessment determined that the bioavailability of constituents is very limited and benthic community assays showed no evidence of ecological impairment. The Human Health Risk Assessment determined that remediation of onsite impacts and implementation of land use restrictions were to be part of the overall remedy along with a post-remediation groundwater monitoring program.
Key Challenges
GEI’s engineers developed a detailed design and specifications for an IRM consisting of a supported excavation to remove approximately 30,000 cubic yards of impacted soils to a maximum depth of about 28 feet, followed by backfilling. Remedial construction was completed in early 2016, and preparation of a final Remedial Action Plan (RAP), which includes proposed land use restrictions and a long-term groundwater monitoring program is underway.