Reducing uncertainty in risk-based screening levels for the volatilization from groundwater to indoor air

摘要

Gasoline constituents were released to the subsurface environment from leaking underground storage tanks (USTs) at a U.S. Department of Defense (DoD) site in northern California. The site conditions were evaluated against the California Regional Water Quality Control Board's six criteria for a low-risk site to determine if the site could be closed as a low-risk site. As part of this effort, a risk-based corrective action assessment was performed to determine the potential current and future impact of gasoline constituents in groundwater on human health at the site and to determine risk-based screening levels (RBSLs). The human health risk assessment was performed using a tiered approach, with each revision including more site-specific information.