Soil Vapor Extraction (SVE) is an in-situ remediation technology for the physical treatment of volatile and semi-volatile contaminants in the vadose zone (unsaturated soils) (EPA, 2012). Soil Vapor Extraction is also referred to as in-situ soil venting or vacuum extraction. It is based on a mass transfer of contaminants from the solid and liquid phases into the gas phase. Vacuum blowers and extraction wells are used to induce gas flow through the subsurface. This gas phase contamination is collected at extraction wells then treated in above-ground systems tailored for the volume and constituent of concern.
Sub-Slab Depressurization System (SSDS) projects have been increasing due to new air quality regulations. We have performed numerous projects.
Air Sparging, also known as in-situ air stripping and in-situ volatilization, is an in-situ remediation technology used for the treatment of saturated soil zones and groundwater contaminated with volatile organic compounds (VOCs). This technique involves the injection of pressurized air into contaminated groundwater enabling the hydrocarbons to change its state from dissolved to vapor state. The injection of air helps to flush the contaminants upward into the unsaturated zone where a vapor extraction system is typically implemented to remove the volatilized contaminants. This technology has beneficial side effects like adding dissolved oxygen to the contaminated groundwater and unsaturated zone soils. This enhances the biodegradation of contaminants below and above the water table.