A Phase I ESA must review federal, tribal, state and local government records. In the Inland Northwest, that means Idaho DEQ’s Facility Mapper and UST/LUST database, Washington Ecology’s Cleanup and Tank Search, Oregon DEQ’s Your DEQ Online, and Montana DEQ’s tank release map. Each state works differently, so ask which sources your report searched.
Why do state records matter in a Phase I ESA?
Federal rules treat the records review as a required part of “all appropriate inquiries,” the federal standard a buyer follows to seek CERCLA landowner liability protections. Under 40 CFR 312.20(b)(3), reviews of federal, tribal, state and local government records must be conducted or updated within 180 days before the date of acquisition. The same section sets a one-year outer limit for the inquiry as a whole.
The goal of the records review is to find conditions that point to releases or threatened releases of hazardous substances. The rule asks the environmental professional to look at current and past uses, waste handling, cleanup activity, engineering and institutional controls, and nearby properties that could affect the subject site.
State agencies hold much of that information. They track leaking petroleum tanks, cleanup sites, and the controls placed on land after a cleanup. No single database covers all four states, which is why a regional report needs a regional records search.
Our Phase 1 ESA service follows ASTM E1527-21 and includes a regulatory database search of federal, state and local environmental records.
What does Idaho publish?
Idaho DEQ runs a public map called the Facility Mapper. DEQ says it helps the public, local governments and environmental consultants find sites managed by its Waste Management and Remediation programs. That includes sites that have environmental covenants, which are land-use limits recorded after cleanup.
The Facility Mapper is hosted by a third party. It offers keyword search, an advanced search that can export lists to a spreadsheet, and a radius search around an address. It can filter by program, including Leaking Underground Storage Tank (LUST), Underground Storage Tank (UST), Voluntary Cleanup Program, Brownfields and Resource Conservation and Recovery Act sites.
DEQ states the limits plainly:
- Older sites with small incidental releases may not be included.
- Sites that lack enough location information may not be included.
- The data updates about twice a month.
- The tool is for information only, and DEQ gives no guarantee of accuracy or completeness.
Tank facilities also link to a separate UST and LUST database that DEQ lists on its Storage Tanks page. For more detail on a site, DEQ points users to its public records request form.
What does Washington publish?
Washington Ecology runs the Cleanup and Tank Search. It offers a master list of all cleanup sites, including sites already cleaned up, plus a Contaminated Sites List, a No Further Action list, leaking underground storage tanks, all regulated underground storage tanks, and an Environmental Covenants Registry. A map tool called What’s In My Neighborhood? finds cleanup sites near an address.
Each site in Ecology’s database of known or suspected contaminated sites gets a Cleanup Site ID (CSID), and electronic records for the site are attached to its entry.
Being in the database does not decide who is liable. Ecology’s early notice letters say that a letter or inclusion in the database “does not mean that Ecology has made a determination about potential liability for cleanup” under the Model Toxics Control Act (MTCA).
Ecology’s MTCA fact sheet explains the ranking behind the Hazardous Sites List. Sites are ranked on a scale of 1 to 5, where 1 is the highest relative risk and 5 the lowest. A site can come off the list after cleanup, once Ecology determines that cleanup standards have been met.
Washington also allows independent cleanups, which owners do without Ecology’s approval. Ecology says they must be reported and that it may require more work later. A “No Further Action” letter through the Voluntary Cleanup Program is one way owners get feedback from the agency.
What does Oregon publish?
Oregon DEQ moved its leaking tank data into an online system called Your DEQ Online. The old LUST database was retired, and its information was migrated on April 16, 2024. DEQ offers a public information database search and an All Sites report for a list view of leaking underground storage tank sites.
DEQ adds cautions on the same page. The data is “working information” used by the agency. Information is not comprehensive for old projects, and some entries may be unconfirmed, outdated or incomplete. For records that are not online, DEQ directs users to a public records request.
What does Montana publish?
Montana DEQ’s tank release data lives in a public GIS map. A user adds the “Montana Tank Substance Releases” layer, then filters by facility name, release number, release status and other fields. No account is needed to view the map.
The instructions show release status values such as open, resolved and reopened. Each release has a facility ID, a confirmed date, and downloadable summary reports.
This layer covers tank substance releases. That is narrower than every contaminated site in the state, so ask your environmental professional what other sources the search included.
At a glance
| State | Main public tool | Good to know |
|---|---|---|
| Idaho | DEQ Facility Mapper, plus the UST/LUST database | Older small releases and sites without location data may be missing. Updated about twice a month. |
| Washington | Ecology Cleanup and Tank Search | A CSID listing is not a liability finding. Sites are ranked 1 to 5. |
| Oregon | Your DEQ Online (LUST data moved April 16, 2024) | Older projects may have records that are not online. |
| Montana | DEQ GIS map, “Montana Tank Substance Releases” layer | Covers tank releases. No account needed. |
What does it mean when a property or neighbor is listed?
A listing is a lead, not a verdict. It tells the environmental professional where to look next.
A listed site can be closed and resolved. It can be open and far away. It can be a neighbor whose plume matters, or an on-site tank that was removed long ago. State agencies say outright that their tools are informational and may be incomplete. Washington’s own letters say a listing is not a liability decision.
For a buyer, the useful questions are simple. Is the listing on the property or next door? Is the status open or closed? Did a cleanup leave controls on the land? Is there a document in the file that explains it?
What does your environmental professional add beyond the database?
The records review is one part of a Phase I. The rule also calls for an inquiry by an environmental professional, interviews, a search for environmental cleanup liens, and a site visit. The professional must also identify data gaps, such as missing location data, and comment on how much those gaps matter.
A database search cannot see a stained slab, an old fill port or a drain that leads somewhere unexpected. A site visit can. Our article on historic commercial building due diligence walks through tank clues like breather pipes and oil-fired heating history. Our piece on reading a building’s original purpose explains why past use drives the questions a report should ask.
Two practical points for buyers:
- Check the timing. Records review and site visit must fall within 180 days before closing, so a delayed deal may need an update.
- Ask for the list of sources. A good report names each database searched and the date it was searched.
Next step
If you are buying in Idaho, Eastern Washington, Eastern Oregon or Western Montana, start with the Phase 1 ESA service page and tell us the address and your closing date. Our areas served page lists where we work.
