SRS conducted a human health and ecological risk assessment to evaluate the current and future potential exposure of onsite and offsite receptors to PCE- and TCE-contaminated soil and groundwater. By using a vapor intrusion screening level (VISL) calculator, SRS identified PCE and TCE in soil gas as a potential threat to future receptors that may reside in buildings constructed onsite. The HHRA evaluated the potential health risks associated with exposure to contaminant of concern (COC) identified in groundwater and soil gas. Site contamination was compared to the applicable risk-based screening levels and Applicable or Relevant and Appropriate Requirements (ARARs).
A Screening Level Ecological Risk Assessment (SLERA) evaluated potential risks to terrestrial receptors from exposure to site soil. The SLERA included an evaluation through both direct exposure and indirect exposure via the food web. The SLERA indicated that the chemicals detected in Site soil do not pose a threat to ecological receptors. The information presented in the SLERA was sufficient to determine that no further data was required to assess ecological risks.
Remedial goal objectives and remedial goals were developed to prevent human exposure to contaminants as well as to restore the groundwater to its beneficial use. Remedial alternatives were developed to achieve the remedial goals. Institutional controls prohibiting use of groundwater were part all remedial alternatives.