Passive Soil Gas Survey to Define Extent of Groundwater Contamination
Challenge
A foam manufacturer documented historical releases of chlorinated solvents and freon that impacted groundwater beneath the plant operations and downgradient of the plant buildings. The North Carolina Department of Environmental Quality (NCDEQ) required that the extent of those impacts be defined downgradient of the source area prior to initiating any corrective action for groundwater at the site.
Solution
Antea Group developed a tactical plan to determine the impacts to groundwater. We conducted a passive soil gas (PSG) survey to identify any additional source areas of contamination, delineate the lateral extent of the contamination, and facilitate the strategic placement of additional shallow monitoring wells.
On December 4, 2013, 28 passive soil gas samplers were placed in a grid pattern into the subsurface. The samplers were collected on December 19, 2013 for analysis of volatile organic compounds.
Result
The PSG survey enabled Antea Group to install additional monitoring wells in optimal locations—which helped to define the extent of impacts in the groundwater. This significantly reduced costs for the client and fulfilled the requirements set by the NCDEQ.
