Terraphase provided comprehensive human health risk assessment (HHRA) support for a large planned residential development in southern California. Groundwater contamination emanating from a closed municipal waste landfill posed a potential threat to the development via vapor intrusion.
Scope of Services
Terraphase developed a detailed hydrogeologic conceptual site model (CSM) and completed two HHRAs. These efforts guided the investigation, evaluation, and decision-making process regarding the need for engineering controls to mitigate vapor intrusion exposures prior to construction. Key activities included characterizing the site’s subsurface conditions, assessing cancer risks and noncancer hazards to future residents, and supporting the incorporation of vapor intrusion mitigation systems only where necessary.
Notable Accomplishments
- Vapor intrusion modeling and risk assessments provided a reliable scientific basis for determining which specific homes required vapor mitigation systems, which optimized both safety and cost-effectiveness of the development
- Ensured the safe and sustainable development of the residential community while effectively collaborating with, and enhancing the services of, other engineering and environmental consulting firms, as well as the client’s legal counsel, to achieve the client objectives
