USTs - General Information, Regulations, and Guideance on the EPA Regulation

Underground Storage Tanks (USTs)

Cleaning Up Underground Storage Tank System Releases

Why do UST releases need to be cleaned up?

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.

How many UST releases are there?

Over 418,000 UST releases had been confirmed as of September 30, 2001. Since then the number has continued to climb, and will continue as older tanks fail, and more tanks are identified that previous unknown. Steady cleanup work has progressed for over a decade and more than 268,000 contaminated sites have been cleaned up. While much good work has been and continues to be done, there are about 150,000 UST sites remaining to be cleaned up. You can go to our corrective action measures archive to see periodic reports on the number of releases and cleanup actions taken (data displayed by state, EPA Region, and Indian Country). Information about cleaning up leaks from USTs is summarized in the tri-fold cleanup brochure.

Are all contaminated UST sites equally dangerous or costly to clean up?

Contaminated UST sites vary considerably. Some are very contaminated sites at which groundwater resources have been adversely impacted and may involve years of cleanup activities that can cost over $1 million. 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 average cleanup cost for a contaminated UST site is about $125,000.

What cleanup methods are available?

Several methods have been successfully used for over a decade to clean up thousands of sites. Often the specific characteristics of the site (its type of soil, proximity to groundwater, and so on) 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.

Are there ways to control the cost of these potentially expensive 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 also has grant money that encourages both environmentally effective cleanups and the redevelopment of these areas .