Tanks that are taken out of service (no longer dispensing fuel) are considered closed tanks. Closure can be either temporary or permanent.

Temporary Closure

Tanks that are not being used currently but will be used again sometime in the future can be temporarily closed. There is no time limit on how long you can keep your UST system out of service without permanently closing it, as long as the UST system meets all the requirements for new or upgraded tanks.

To close your UST system temporarily, you must

  • Obtain a permit from your local building code official and submit a copy of the permit to DEQ.
  • Notify DEQ of the change by submitting a registration form to DEQ.
  • If your UST system is closed for more than three months, leave the vent lines open and functioning, and cap and secure all other lines, pumps, manways, and ancillary equipment.
  • Continue to maintain your corrosion protection system if you have one, and your mechanism of financial responsibility.
  • Keep performing release detection unless the tank is empty (storing less than one inch of product).

Temporarily closed tanks that do not meet all the requirements for new or upgraded tanks must be permanently closed after 12 months. Contact your DEQ regional office for more information.

Permanent Closure

You can close your UST system permanently in one of two ways: either remove the tank system (tanks and connected piping) from the ground, or close the system in place. Closing in place generally requires filling the tank with an inert, solid material. Consult your local building code official for what kind of tank closure is allowed by your locality.

To close your UST system permanently, you must:

  • Obtain a permit from your local building code official and submit a copy of the permit to DEQ.
  • Empty and clean the tank by removing all liquids and accumulated sludges.
  • If closing in place, fill the tank with a solid, inert substance, such as sand or a cement slurry.
  • Assess the site for any petroleum contamination (soil sampling) and submit the sampling results to DEQ.
  • If soil sampling indicates the tank has leaked, report the release to DEQ promptly.
  • Notify DEQ of the change in status by submitting a registration form to DEQ.