The goal of Phase 2 soil and groundwater investigations and subsequent remediation is to obtain environmental regulatory case closure. Closure of leak cases by regulatory agencies requires satisfaction of the following criteria:
- the source of contamination has been removed
- contaminant concentrations are decreasing with time
- the extent of contamination in soil and water is known
- there is no risk to human health and safety, sensitive receptors or the environment.
Recent conversations by ERAS with local regulators indicate that the State of California is allowing for and requesting local agencies to evaluate the possibility of risk-based closures.
Risk based analysis may involve evaluation of vapor intrusion into buildings. (see above for information on soil gas and indoor air risk) However, it also allows for case closure even with the presence of soil and groundwater contamination.