Colorado
Regulated storage tank registrations
Colorado regulated storage tank registrations
In Colorado, petroleum storage tanks are regulated by the Division of Oil and Public Safety (OPS), in the Colorado Department of Labor and Employment. OPS says its Petroleum Program regulates petroleum storage facilities with underground storage tanks (USTs) that hold 110 gallons or more and aboveground storage tanks (ASTs) that hold between 660 and 40,000 gallons. Every regulated tank system must have an installation permit and must be registered.
In a Phase I ESA
OPS's tank records are the Colorado form of the state registered storage tank records that ASTM E1527-21 lists as a standard source. The general reading of a registered tank listing is on the UST / AST page. A registration says a tank system exists or existed. Releases are a separate record, the petroleum release event.
Four Colorado details shape the search.
- Some tanks are outside the program. OPS names notable exemptions. For USTs they are on-site heating oil tanks, farm tanks with a capacity of 1,100 gallons or less, stormwater or wastewater collection systems, oil-water separator tanks and process flow-through tanks. For ASTs they are tanks on farms or residential properties, tanks associated with oil or gas production, on-site heating oil tanks, and tanks at construction or earth-moving sites. OPS says the full list is in the Colorado Petroleum Storage Tank Regulations. A tank of one of these kinds may never have been registered, so the absence of a registration does not show the absence of a tank.
- Registration follows first use. A person who owns a regulated tank system must notify OPS within 30 days of the start of operation by submitting the AST or UST registration form. The registration and renewal fee is $35 per tank per year.
- "In use" has a legal meaning. OPS says a storage tank is considered by law to be in use if it is not permanently closed or in approved temporary closure. A tank can be temporarily closed for up to 12 months by being emptied to less than one inch of product and notifying OPS. It can be permanently closed by notifying OPS, emptying and inerting the tank, and either closing it in place or removing it. For a permanently closed tank, ask which of the two it was: a tank closed in place is still in the ground.
- The fee history bears on cleanup funding. To be eligible for the Petroleum Storage Tank Fund, a tank owner or operator must have registered the tanks and paid the current and past annual registration fees on a timely basis.
OPS says the Division administers 7 CCR 1101-14 (Petroleum Storage Tanks) and Colorado Revised Statutes Title 8, Article 20.5 (Petroleum Storage Tanks).
Where to look a site up
- OPS's Petroleum page links COSTIS-IA, the portal of the Colorado Storage Tank Information System, to search records. OPS points to it for information on storage tank facilities. More on it is on the COSTIS-IA and petroleum file requests page.
- OPS's Maps page carries a map of OPS regulated storage tank facilities and links three datasets on the Colorado Information Marketplace, two of them about tanks. OPS describes one as information about storage tanks registered with OPS, and the other as information about all facilities with at least one active regulated storage tank. Since the facilities dataset is described by active tanks, check the tanks dataset and COSTIS-IA for a site whose tanks are all closed.
- OPS says there is no guarantee that the data in its map application is 100% accurate, correct, current or complete, and asks to be contacted for verification of records.
- The Release Prevention and Inspection Sections are at cdle_oil_inspection@state.co.us. OPS's Technical Assistance Line is 303-318-8547.
Getting the file
OPS's Petroleum Data & File Request page links a Petroleum File & Data Request form. OPS describes it as the route for data sets such as tanks or facility types and for individual files from a facility, such as reports and letters.
Sources
Colorado Department of Labor and Employment, Division of Oil and Public Safety pages, read October 7, 2026, no modified date shown: