Underground storage tank (UST) program

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Coronavirus (COVID-19) regulatory update

March 27, 2020 – Please read our letter outlining regulatory expectations for UST owners/operators and service providers while under the Governor’s Stay Home – Stay Heathy order.

We want everyone to stay safe and healthy, and appreciate your understanding.

Our Underground Storage Tank (UST) program protects the environment by regulating more than 9,200 tanks across the state. Are you a tank owner? Learn what you need to do to ensure your underground tanks stay safe.

Program overview

Our UST program is one of the largest pollution prevention programs at Ecology. Every year, just over 3 billion gallons of fuel are stored underground. Our job is to make sure it stays there safely until it goes into your tank.

We currently regulate more than 9,200 tanks at more than 3,400 facilities, including gas stations, industrial and commercial properties, and government-owned properties.

We work to ensure these tanks are installed, managed, and monitored to prevent releases into the environment. The federal requirement is to inspect tanks every three years but we inspect tanks every two and a half years. We conduct compliance inspections at about 1,200 facilities each year and provide technical assistance to tank owners.

Washington has a federally-approved UST program. This means that state law, not federal law, applies to UST systems in this state.

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Annual fees

The annual fee for each underground storage tank is:

Sources and causes of releases

We collect data on the sources and causes of releases from UST systems in Washington. We are required to report this information under the Underground Storage Tank Compliance Act of 2005.

Home heating oil tanks

We do not regulate home heating oil tanks. For help and information, please contact the Pollution Liability Insurance Agency (1-800-822-3905).