What's on the Cortese List? [Video Explainer]
The Cortese List is California's official compilation of hazardous waste sites that must be disclosed in real estate transactions. Despite its name, it is not a single database — it is a cross-reference of four separate regulatory systems. The video below explains how it works in 35 seconds.
What the Cortese List is
Created under Government Code §65962.5, the Cortese List identifies sites where hazardous waste has been released, stored, or disposed of in ways that may affect nearby properties. If a parcel is located near a listed site, sellers must disclose that fact to buyers as part of the NHD process.
The four databases behind the list
- DTSC EnviroStor. The Department of Toxic Substances Control's inventory of cleanup sites, permitted facilities, and corrective action locations.
- SWRCB GeoTracker. The State Water Resources Control Board's database of leaking underground fuel tanks and groundwater cleanup sites.
- EPA Superfund. Federally designated National Priorities List sites with ongoing remediation.
- CalGEM. California Geologic Energy Management's records of oil and gas wells, including idle and orphan wells.
Impact on buyers, sellers, and lenders
A nearby Cortese List entry does not automatically make a property unmarketable. It does mean buyers should investigate further — asking about cleanup status, groundwater monitoring, and any deed restrictions or notices recorded against the property. Lenders may also flag these entries for additional environmental review.
Verity NHD checks all four Cortese List sources and presents the results alongside the statutory hazard zones. Learn more about what's covered on our NHD report page.
How proximity is measured
Verity NHD checks all four Cortese List databases by querying each source for active sites within a defined radius of the subject parcel. The search radius follows industry-standard proximity thresholds used by environmental screening providers — typically one-quarter mile for leaking underground storage tanks and one mile for Superfund and DTSC cleanup sites. Results include the site name, status (active, closed, or under remediation), distance from the property, and the regulatory agency overseeing the site. This gives buyers and their advisors enough context to decide whether additional investigation — such as a Phase I Environmental Site Assessment — is warranted before closing.
Key takeaways
- The Cortese List is not a single database — it cross-references four separate regulatory systems maintained by DTSC, SWRCB, EPA, and CalGEM.
- Government Code §65962.5 requires disclosure of nearby listed sites as part of the NHD process.
- A Cortese List entry near a property does not make it unmarketable — cleanup status, distance, and remediation progress all matter.
- Buyers should treat a nearby listing as a signal to investigate further, not as a reason to walk away automatically.
- Verity NHD queries all four Cortese List sources and presents results with site names, distances, and regulatory status in every report.