Waste Programs Division: Underground Storage Tanks: Inspections and Compliance

Prevention and timely detection of underground storage tank leaks are critical to protecting human health and the environment. The UST Inspections and Compliance Unit oversees UST owner and operator efforts to meet state and federal requirements related to UST installation, operation and closure. ADEQ also has delegation agreements with the State Fire Marshal's Office and some of the larger Arizona cities to assist with this effort. The unit also regulates the legal requirement that owners and operators have a financial assurance mechanism to help cover the cost of investigating and cleaning up a release and possible third party liability.


Please return all completed forms to: (Original signatures and dates are mandatory)

Arizona Department of Environmental Quality
UST Program
1110 West Washington Street
Phoenix, Arizona 85007

Closing USTs

If the UST owner or operator is planning on closing their tanks (tank removal or closing in place), please contact ADEQ for a closure number at least 30 days prior to any closure activities. The request must be submitted in the form of a letter. In addition to the letter, it is still necessary to submit a Notification Form within 30 days of closure. Upon receipt of an ADEQ closure number, the owner may contact the appropriate fire authority for the necessary permits.

For more information on closing a UST

Temporary Closure

The UST owner or operator may temporarily close their UST for up to 12 months by following these requirements.

  • Continue to monitor for leaks by maintaining the UST's leak detection (unless the tank is empty). Continue to monitor and maintain any corrosion protection systems.
  • If an UST remains temporarily closed for more than three months, the owner must leave the vent lines open but cap and secure all other lines, pumps, manways and ancillary equipment.
  • Prior to the expiration of the temporary closure period, the owner must permanently close the UST or submit a written request to ADEQ for an extension of temporary closure.

Permanent Closure and Removal

Safety is a significant concern when permanently closing and removing a tank. In Arizona, the owner must use a certified UST Service Provider to perform the potentially hazardous activities of emptying and cleaning USTs.

The tank must be emptied and cleaned by removing all liquids, dangerous vapor levels, and accumulated sludge. These activities need to be carried out carefully by a certified service provide following standard safety practices.

Click here to obtain a list of UST Service Provider Certification Listings.

Delivery Prohibition

Notification to Product Deliverers: Facilities with Underground Storage Tanks that are Ineligible for Petroleum Delivery (Word) (PDF)

U.S. EPA has Authority to Fine Tank Owners for Violations Observed During an Inspection

The United States Environmental Protection Agency (U.S. EPA) has federal authority to enforce underground storage tank (UST) laws. Although, ADEQ has a cooperative agreement with U.S. EPA to implement the UST program in Arizona, ADEQ and U.S. EPA frequently coordinate on facility inspections.

What some UST owners and operators do not know is that U.S. EPA has the authority to fine tank owners or operators at the time of inspection for violations of UST operational requirements. ADEQ wants to ensure that UST owners, operators, and other interested persons are aware of U.S. EPA's field citation authority.

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Installing and Registering USTs

To install an underground storage tank, a UST owner will first need to obtain a construction permit from their local fire authority. The owner will need to notify ADEQ within 30 days of bringing the installed tank into operation. Please fill out and submit a UST Notification form.

Related Statutes and Rules

State statutes relating to USTs: Chapter 6 of Title 49 of the Arizona Revised Statutes (UST Statutes) A.R.S. 49-1001 - 1093
State rules relating to USTs: Chapter 12 of Title 18 of the Arizona Administrative Code (UST Program Rules)
Federal rules relating to USTs: Code of Federal Regulations (C.F.R.) 40 CFR

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