Arizona law requires owners and operators of UST systems to report a confirmed or suspected release of "regulated substances," which includes petroleum, to ADEQ within 24 hours. Always report a suspected or confirmed release to your insurance company to file a claim and preserve coverage.

Even without  obvious visual or olfactory evidence of a release — such as stained soils or a strong hydrocarbon odor—the presence of other indicators may suggest a release has occurred from the UST system. Examples of conditions qualifying as a “suspected release” include:

• Vapor or product is detected in vapor monitoring or groundwater monitoring wells used for leak detection.
• Inventory control discrepancies indicate that a release may have occurred (a gain or loss of product greater than 130 gallons + 1% of throughput).
• Alarms from automatic tank gauging (ATG) systems, interstitial monitors, sump sensors, automatic line leak detector, etc., indicate that a release may have occurred.
• Statistical inventory reconciliation (SIR) results indicate either a Fail or two consecutive Inconclusive.
• Unexplained loss of product.
• Unexplained presence of water in the tank or sump.
• Product dispensing equipment does not dispense product or dispenses product at a greatly reduced rate.
• Internal tank (periodic) inspection results reveal perforations, corrosion holes, weld failures, or other similar defects.

Reporting a Suspected UST Release

UST owners and operators are required to notify ADEQ within 24 hours of a release or suspected release of an underground storage tank using the myDEQ portal | Log In >

If the suspected release is a regulated UST spill or overfill of 25 gallons or less, that is contained or cleaned up within 24 hours, the UST owner/operator is not required to report the incident to ADEQ.

Suspected Release 14-Day Report

A UST owner/operator is required to submit a report to ADEQ within 14 calendar days after the suspected release discovery date or the suspected release notification date, whichever is earlier. To meet this requirement, the UST owner/operator may either use the Release Status Report attached to the above-referenced ADEQ letter, or they may create their own report form. Regardless of the report’s format, it must contain the information referenced in Arizona Revised Statutes (A.R.S.) § 49- 1004(C) and Arizona Administrative Code (A.A.C.) R18-12-260(C).

Suspected Release 90-Day Report

A UST owner/operator is required to submit a report to ADEQ within 90 calendar days of receipt of the above-referenced ADEQ notification letter. The 90-Day Report must contain the information referenced in A.A.C. R18-12-251(C) and (F). Based upon the type of suspected UST release, ADEQ may require the UST owner/operator to submit information such as tank tightness test results, product piping test results, soil sampling and laboratory analytical report information, tank repair documentation, etc.

Guidance

The following are designed to help owners/operators determine necessary actions when there is a suspected release:

• Suspected Release Process Flow Chart (Contamination) | View/Download >
• Suspected Release Process Flow Chart (Equipment) | View/Download >

All (24-hour, 14-day, and 90-day) suspected release reports must be submitted using myDEQ | Learn More >