Vapor Intrusion

Duncklee & Dunham has designed soil gas Vapor Intrusion Mitigation Systems (VIMS) for residential and Brownfields properties in NC and VA in accordance with EPA’s Technical Guidance, the North Carolina Inactive Hazardous Sites Program, and differing state and federal regulatory requirements, and have involved a wide range of geologic settings including coastal plain sediment, piedmont and mountain saprolite, competent igneous and metamorphic rocks, marine-deposited limestone, shale and sandstones, and basin and range sediments. Contaminants remediated include nutrients, metals, petroleum hydrocarbons, volatile organic compounds (VOCs), petroleum oxygenates such as MTBE, chlorinated VOCs, and semi-volatile organic compounds.

Duncklee & Dunham has also designed and implemented soil-remediation strategies that have included excavation and removal of impacted soil, air-sparge and soil-vapor-extraction systems, sub-slab vapor intrusion mitigation systems (new slabs and retro-fit installations), multi-phase extraction for petroleum hydrocarbons and other VOCs, in situ mixing and stabilization using chemical reagents (hydrogen peroxide, Fenton’s Reagent, potassium and sodium permanganate, sodium persulfate, magnesium oxide, and oxygen-releasing compounds) and biological enhancers (carbon sources such as molasses, sodium lactate, or emulsified vegetable oils) for in situ remediation, risk-based closures, and UST/AST abatements.

We hosted a Vapor Intrusion symposium on August 24, 2017 discussing vapor intrusion assessments and guidelines to follow on evaluating vapor intrusion in North Carolina.