Effect of dissolved oxygen manipulation on diffusive emissions from NAPL-impacted low permeability soil layers.

Aquifer physical model experiments were performed to investigate if diffusive emissions from nonaqueous phase liquid (NAPL)-impacted low-permeability layers into groundwater moving through adjacent NAPL-free high-permeability layers can be reduced by creating an aerobic biotreatment zone at the interface between the two, and if over time that leads to reduced emissions after treatment ceases. Experiments were performed in two 1.2-m long × 1.

Proof-of-concept study of an aerobic vapor migration barrier beneath a building at a petroleum hydrocarbon-impacted site.

A proof-of-concept study was conducted to evaluate an alternative to traditional extraction-based subslab vapor mitigation systems at sites with petroleum hydrocarbon and/or methane vapor impact concerns. The system utilizes the slow delivery of air beneath a foundation to attenuate vapor migration to the building via aerobic biodegradation. The study was conducted at a site having elevated hydrocarbon plus methane and depleted O(2) vapor concentrations (160 mg/L and <1% v/v, respectively) beneath a building having a 195 m(2) footprint and a basement extending 1.