Resources for underground storage tank owners & operators

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Updated Underground Storage Tank rule takes effect Nov. 24, 2023

The legislature recently passed a law directing the Pollution Liability Insurance Agency (PLIA) to establish and run a new state financial assurance program for UST owners and operators. Ecology updated our underground storage tank regulations to allow for this new program. The changes take effect Nov. 24, 2023.

To learn more about the new financial assurance option, visit PLIA's rulemaking page. To learn more about Ecology's rulemaking, visit our WAC 173-360A rulemaking page.

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Proper underground storage tank (UST) operation & maintenance can help prevent leaks, which protects the environment and the value of your property. Operators must be certified through an Ecology-approved training program. Ecology inspects tank systems at least every three years.

Be sure to check with the city and county authorities where your tank is located to find out if there are other requirements for your USTs.


Quick stop for UST forms, checklists, and guidance

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Did your tank leak or spill?

Tell the Ecology office in your region within 24 hours. Then follow the instructions in What to do if you find a leak or spill from your underground storage tank.

Annual tank fees  

Tank fees are paid to Department of Revenue as an endorsement on the business license fee. The fee for each tank is:

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