Screenings and Preliminary Assessments

SCREENING

Screening is the DEQ Cleanup Section's initial evaluation of sites that have been added to the agency’s Environmental Cleanup Site Information system. (ECSI is DEQ’s electronic database of sites with known or suspected hazardous substance contamination.) DEQ adds sites to ECSI based on information from a variety of sources, including referrals from other programs, spills, complaints, and unsolicited reports, as well as from Site Assessment staff’s discovery of sites that may present significant threats to human health or the environment. Site screening is designed to:

• determine whether a release of a hazardous substance has occurred or could occur;
• determine whether site contamination poses or may pose a significant threat to human health or the environment;
• determine what further actions are needed at a site, and the priority for those actions;
• document Site Assessment’s decision-making process; and
• provide information for updating the ECSI database.

There are six general actions associated with a site screening, as explained below:

1. Gather available site data. Site Assessment staff first review readily available information from internal DEQ files, U.S. Geological Survey topographical maps, and other agencies. Then, to obtain additional facility data, staff normally send an information request letter to the site owner or operator. Tailored to the site, this letter may request site investigation or cleanup reports not in DEQ files, information about disposal of hazardous substances used or generated at the facility, details on historic or current facility operations, and other related information.
2. Evaluate site information; develop and document conclusions. Site Assessment’s standard screening write-up is called a Strategy Recommendation, which addresses site history and contamination issues, highlights likely pathways of exposure, presents DEQ’s recommendations for further action (if any- sometimes screenings result in no-further-action determinations), and lists references. For sites needing further actions, the Strategy Recommendation indicates the priority for those actions (see item #3 below). The Strategy Recommendation also presents a listing recommendation (see item #4 below).
3. Assign a priority for further site action(s). Using DEQ’s Site Assessment Prioritization System, or SAPS, staff determine the priority – low, medium, or high – for further actions needed. SAPS integrates many features associated with the site, and gives a final "score" that Site Assessment staff use in assigning a site priority. The priority given depends on information, such as:

• manner of release and media affected by hazardous substances;
• approximate volume(s) of contaminated media at site;
• toxicity and water solubility of contaminant(s) of concern;
• groundwater depth and main uses of groundwater within 2 miles of the site;
• distance to the nearest recorded drinking water well;
• distance to surface water, and main uses of surface water within 2 miles of the site;
• permeability of surface and near-surface soils;
• main land uses within ½ mile of site;
• site’s proximity to defined Sensitive Environments [Oregon Administrative Rules 340-122-115]; and
• likelihood of human direct contact with hazardous substances.

4. Make a listing recommendation (i.e., should the site be added to the Confirmed Release List or Inventory?). If a hazardous substance release has been documented, the site may qualify for the CRL. The site may also qualify for the Inventory, if a release has been documented and a PA or PA Equivalent has been completed. (See below for a discussion of PAs and PA Equivalents.) If a site is eligible for either the CRL or Inventory, state law obligates DEQ to pursue listing as a way to notify the public of contaminated sites. CRL or Inventory listing is not meant to assign cleanup liability to specific persons or companies.
5. Update ECSI. When the screening is final, Site Assessment staff update the ECSI database with information on site contamination issues, concentrations of hazardous substances in various media (if data is available), recommended further actions (including CRL/Inventory listing recommendations), and site priority. A primary objective of updating ECSI after a screening is to provide, for other DEQ staff and the general public, a concise and current summary of site issues and the human health or the environmental threats the site may pose.
6. Notify owner/operators of screening results and conclusions. To complete the screening, Site Assessment staff send a letter to responsible parties describing what further actions are needed and under what priority. This letter is often referred to as an "options letter," because it lays out several choices available to RPs. For low- or medium-priority sites, DEQ usually gives RPs three options: 1) pursue further action under DEQ’s Voluntary Cleanup Program; 2) implement further actions independently (i.e., without VCP oversight); or 3) take no action and wait for DEQ to take the next step. For high-priority sites (where risks to human health or the environment are considered imminent or substantial), DEQ may limit RPs’ options so that the agency retains more control over the nature and timing of remedial actions. A "no-further-action" letter is another possible outcome of a screening.

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