Oregon
Site Assessment Program
Oregon Site Assessment Program
The Site Assessment Program of the Oregon Department of Environmental Quality (DEQ) discovers and assesses hazardous substance sites that may require further action, ranks them by threat to human health and the environment, oversees limited removal and remedial actions, and maintains the cleanup data in Your DEQ Online. DEQ calls it the entry point into its Voluntary Cleanup and Site Response Programs, and says it performs a "gate-keeping" function.
In a Phase I ESA
ASTM E1527-21 does not name site assessment records among its standard record sources. They are the documents behind an Oregon cleanup site entry, and they explain why a site was entered and what DEQ asked for next. Six details shape how to read them.
- Sites arrive many ways. DEQ's examples are referral from other DEQ programs or other public agencies, reports of chemical spills, citizen complaints, contamination appearing on adjacent properties, data submitted voluntarily by property owners or their representatives, and staff research to discover sites that could affect what it calls Vulnerable Areas. Staff add new sites to Your DEQ Online at this stage.
- A screening is mostly a desktop review. DEQ says a screening is a brief review of readily available information on site history, contamination and the ways people or the environment could be exposed. It calls screenings primarily "desktop" exercises that occasionally include site visits but rarely involve DEQ sampling. Do not read a screening as an investigation of the property.
- The write-up is a Strategy Recommendation. It addresses site history and contamination issues, highlights likely exposure pathways, gives DEQ's recommendations for further action, if any, and a priority, and presents a listing recommendation. DEQ says screenings sometimes end in a no-further-action determination.
- The priority is low, medium or high. Staff assign it with a DEQ ranking tool, the Site Assessment Prioritization System. The inputs DEQ lists include the manner of release and the media affected, the toxicity and water solubility of the contaminants, groundwater depth, the distance to the nearest recorded drinking water well, the distance to surface water, soil permeability, nearby land uses, and the likelihood of direct human contact.
- The owner gets an options letter. For low or medium priority sites, DEQ says it usually gives responsible parties three options: pursue further action under the Voluntary Cleanup Program, carry out further actions independently, or take no action and wait for DEQ to take the next step. For high priority sites it may limit the options. A site with an options letter and nothing after it may be one whose owner chose to wait.
- Staff may have asked the owner for records. To gather data, staff normally send the owner or operator an information request letter. DEQ says it may ask for investigation or cleanup reports not in DEQ files, information about the disposal of hazardous substances, and details of historic or current operations. The answers can be in the file.
DEQ says the program tracks its costs and seeks to recover them when it recommends further investigation or cleanup.
What the record shows
Beyond a screening, DEQ describes three kinds of assessment.
| Assessment | What DEQ says it is |
|---|---|
| Preliminary Assessment | A more formal and detailed investigation, conducted under Oregon Revised Statute 465.245 at sites where hazardous substances may pose a significant threat. It usually comes with a site visit and sometimes includes limited sampling |
| Expanded Preliminary Assessment | An added investigative effort and report with sampling, designed to confirm the presence of contamination |
| Site-Specific Assessment | An assessment with sampling designed for brownfield sites, to learn whether contamination could affect a proposed redevelopment |
DEQ says a Preliminary Assessment is not intended to fully characterize site contamination or to quantify the magnitude of site risks. Its outline of the report asks for the ownership history and the operating history as far back as possible, the regulatory history with permits and past inspections, the source areas, and the exposure pathways. Where one exists, it can fill gaps in a property's history.
Where to look a site up
- DEQ says information from Site Assessment evaluations is summarized in Your DEQ Online, which is available to the public. Search the Your DEQ Online Public Records Portal.
- The Environmental Cleanup Program is at Cleanup.ResolutionCenter@DEQ.oregon.gov and 1-800-452-4011.
Getting the file
Ask for the Strategy Recommendation, the information request letter and its answer, the options letter, and any Preliminary Assessment report. The route is described on the Your DEQ Online and public records requests page.
Sources
Oregon Department of Environmental Quality pages, read October 7, 2026, no modified date shown: