Cleaning Up Underground Storage Tank (UST) Releases
EPA works with its state, territorial, tribal, and industry partners to clean up releases from underground storage tanks (USTs). Left unattended, releases can contaminate soil, groundwater, surface water, or indoor air. EPA is developing and implementing strategies that advance cleaning up stalled or legacy UST releases, as well as recently identified releases. Cleaning up UST releases protects our environment and the health of Americans.
- Why do UST releases need to be cleaned up?
- How many UST releases are there?
- Are all contaminated UST sites equally dangerous or costly to clean up?
- What cleanup methods are available?
- What are some examples of cleanup strategies states are using to help reduce their backlog of cleanups remaining?
- Are there ways to control the cost of these potentially expensive cleanups?
- Looking for more information on UST cleanups?
EPA's federal underground storage tank (UST) regulations require that contaminated UST sites must be cleaned up to restore and protect groundwater resources and create a safe environment for those who live or work around these sites. Petroleum releases can contain contaminants like MTBE and other contaminants of concern that can make water unsafe or unpleasant to drink. Releases can also result in fire and explosion hazards, as well as produce long-term health effects.
Over 566,000 UST releases had been confirmed as of March 2022. Steady cleanup work has progressed for over a decade and nearly 506,000 contaminated sites have been cleaned up. While much good work has been and continues to be done, there are about 61,000 UST sites remaining to be cleaned up. To understand the makeup of these sites and why the pace of cleanups is slowing, EPA analyzed the cleanup backlog. You can go to our UST Performance Measures archive to see periodic reports on the number of releases and cleanup actions taken (data displayed by state, EPA region, and Indian country).
Contaminated UST sites vary considerably. Some are very contaminated sites at which drinking water resources have been adversely impacted and may involve years of cleanup activities that can cost millions of dollars. Other sites may involve relatively minor or no groundwater contamination that may allow cleanup contractors to restore the site more quickly and at less cost. Some contaminated sites have impacted only surrounding soil and have not involved groundwater—these are generally easier and less expensive to clean up. The Association of State and Territorial Solid Waste Management Officials (ASTSWMO) conducts an annual survey of costs incurred by state fund programs for cleaning up releases from USTs. Combined, these state fund programs raise and spend approximately $1 billion per year in addition to federal outlays from the Leaking Underground Storage Tank (LUST) Trust Fund and amounts paid by responsible parties.
Several methods have been successfully used for over a decade to clean up thousands of sites. Often the specific characteristics of the site (for example its type of soil, proximity to groundwater) make it a better candidate for some cleanup methods rather than others. A contaminated site will need a site characterization (also referred to as site assessment as the terms are used interchangeably) that can help professionals choose the best cleanup method. Professional cleanup contractors base their decisions on site-specific investigations and with local environmental agency approval. In some cases, state or federal regulators take the lead at a contaminated UST site and will make all the cleanup decisions.
What are some examples of cleanup strategies states are using to help reduce their backlog of cleanups remaining?
These stories highlight cleanup strategies that states used to help reduce their backlog of releases.
- California’s Impressive Backlog Reduction And Continuing Efforts To Increase LUST Cleanups (PDF)(2 pp, 243 K, About PDF)
- Colorado’s RBCA And “SMART” Approach To LUST Cleanups (PDF)(2 pp, 443 K)
- Minnesota Commits To Continuous Improvement By Reducing The Number Of Legacy Underground Storage Tank Releases (PDF)(2 pp, 274 K)
- Oklahoma Reduced Legacy Releases By 86 Percent Since 2005 (PDF)(2 pp, 305 K)
At the September 2019 Association of State and Territorial Solid Waste Management Officials (ASTSWMO) LUST workshop, participants shared information about challenges and solutions state programs encounter in closing UST release sites and advancing cleanups.
EPA is committed to helping state and local agencies make cleanups faster, more effective, and less expensive. EPA is working with states to encourage the use of expedited site assessment and alternative cleanup technologies. We are also encouraging state and local agencies to incorporate risk-based decision-making and pay-for-performance agreements into their corrective action programs. EPA funds grants that encourage environmentally effective cleanups and the redevelopment of these areas.
Looking for more information on UST cleanups?
Leaking Underground Storage Tanks (LUST) Corrective Action Resources - Technical information and resources about cleaning up UST releases
- Release Discovery and Confirmation - Information about detecting UST releases early, determining the source of releases, identifying the fuels released, locating imminently threatened receptors, and initiating appropriate responses
- Site Characterization and Conceptual Site Model - Information about determining location of USTs and transmission piping, what contaminants are present, where contamination may have moved, the site assessment process, and potential technical and reporting requirements
- Corrective Action - An overview of the corrective action process, as well as operation, maintenance, and monitoring requirements that will likely be an integral part of the process
- Site Closure - Information about characterizing risk and closure, maintaining and abandoning sampling points, documenting and reporting, and closure records
The National LUST Cleanup Backlog: a Study of Opportunities - An analysis of the cleanup backlog
Petroleum Brownfields - Information and resources on reusing cleaned up petroleum sites
Responsible Party Search Guide for the Underground Storage Tank Program - Reference materials and a step-by-step description of how to conduct a responsible party search