Risk assessment involves evaluating the human health and ecological risks at all VRP sites in order to protect the wellbeing of both.
The VRP risk assessment approach is required at all VRP sites, including sites in the Independent Cleanup Process (ICP), and it consists of two processes: one for human health and the other for ecological receptors.
The approach for human health is a two-step process. First, Volunteers compare adequate site data to conservative, standardized risk-based screening levels found in Factsheet #12 Soil Cleanup Levels and the Groundwater Cleanup Levels in Factsheet #13 Groundwater Cleanup Levels.
Second, if the site data exceed the screening levels, the Volunteer can choose to use the screening levels as the cleanup levels and begin cleanup immediately. Alternatively, the Volunteer can conduct a site-specific risk assessment to calculate risk under conditions of unrestricted and restricted land use.
The results of the site-specific risk assessment are compared to established risk limits (see Factsheet #11 Risk Assessment) to determine further cleanup actions, including establishment of a Use Control Area (UCA), as appropriate.
The DEQ recognizes not all cleanup sites will present the same types of ecological issues. In order to address this, DEQ has developed the following stepwise approach to ecological risk assessment:
Each subsequent step of the ecological risk assessment process is a more complex evaluation than the previous step. Some sites may be excluded from the ecological risk assessment process in the early steps, with relatively little effort.
If the early steps indicate a need for more complex assessment, then the information that has been already gathered will support and reduce the effort needed for subsequent ecological risk assessment procedures.