Colorado

Petroleum release events

Agency Colorado Department of Labor and Employment, Division of Oil and Public Safety

Colorado petroleum release events

Colorado's leaking tank records are the petroleum release events of the Division of Oil and Public Safety (OPS). OPS's Remediation Section administers the laws and regulations that require owners and operators of regulated tank systems to report and respond to releases from those systems. OPS's public data covers open events and closed ones.

In a Phase I ESA

Release events are the Colorado form of the state leaking storage tank records that ASTM E1527-21 lists as a standard source. The general reading of a leaking tank listing is on the LUST page. Five Colorado details shape how to read one.

Not every spill becomes an event. OPS says a release does not need to be reported if it meets all of these: it occurs onto an impervious surface, is less than 25 gallons, is cleaned up within 24 hours of occurring, does not contact soil, and does not enter a storm drain. Its guidance says to notify OPS of any reportable release within 24 hours of discovery. So the absence of an event does not show the absence of a small spill.
Closed means No Further Action. OPS describes closed events as releases that have been issued a No Further Action determination. It issues the letter once the release has been shown to be a low risk to human health and the environment.
Closure is by tier. OPS says it evaluates risk by a formal method based on ASTM Standard E 1739-95, which allows several closure criteria, or tiers, and that its database indicates the criteria applied to each archived release. Two of the four tiers leave contamination at or beyond the property boundary. See Petroleum release closure criteria.
A closed event can come back. OPS says a petroleum release investigation may be reopened if exposure conditions change.
A second record may exist. OPS tells tank owners to call the Colorado Department of Public Health and Environment as well if fuel enters a storm drain or surface water, and says it will not report the release for them. Check Environmental spill and release reporting for that side.

Who runs the cleanup

The owner or operator. OPS says the owner or operator of a regulated petroleum storage tank facility is responsible for assessing and remediating a release upon discovery, and typically contracts a Recognized Environmental Professional. Once a release is confirmed, OPS requires the release to be characterized. A corrective action plan is required when the site characterization report shows that remediation is necessary.
State Lead. This program assists owners of petroleum-impacted properties who never owned or operated a petroleum storage tank system on the property. The owner must first become eligible to the Petroleum Storage Tank Fund as a person who bears no responsibility for the release, then ask OPS in writing to carry out the assessment and remediation.
State Lead for Responsible Parties. OPS says this program assists small business owners/operators and non-owners/operators with active or closed petroleum storage tank facilities. OPS takes over the day-to-day management of the cleanup and recovers its costs from the Fund in line with the responsible party's eligibility. The responsible party pays OPS for costs above the amount the Fund reimburses.

Where to look a site up

OPS's Maps page links an interactive map of open petroleum releases. OPS says it shows releases from storage tank systems regulated by and reported to OPS, with well permit locations added. OPS's page says releases at locations that do not yet have latitude/longitude data "are included in the data table, but on the map", which is the sentence as OPS prints it, so search the data table as well as the map.
The same page links the dataset Active and Closed OPS Petroleum Release Events in Colorado on the Colorado Information Marketplace. OPS says it includes the open event locations and the closed events.
OPS says petroleum release information is archived in the OPS database, and its guidance links the portal it calls COSTIS-IA.
The Remediation Section is at 303-318-8547 and cdle_remediation@state.co.us.

Getting the file

OPS's Petroleum Data & File Request page links a Petroleum File & Data Request form for individual files from a facility, such as reports and letters. OPS says information provided to it on submitted forms or in other communication is available to the public upon request.

Sources

Colorado Department of Labor and Employment, Division of Oil and Public Safety pages, read October 7, 2026, no modified date shown: