Underground Storage Tanks (UST)

Underground storage tank system illustration

Underground Storage Tank (UST) Program Overview

The purpose of the Underground Storage Tank (UST) Program is to protect public health and the environment from UST spills, leaks, emissions, discharges, escapes, leaches or disposals (also known as releases) of petroleum and other regulated hazardous substances into groundwater, surface water or soils.

The program regulates the majority of USTs in Arizona with the exception of those in Indian Country. Nearly all USTs at these sites contain petroleum. These sites include marketers who sell gasoline to the public (such as service stations and convenience stores) and non-marketers who use tanks solely for their own needs (such as fleet service operators and local governments). 

What is a UST system? | Learn More >
Which USTs are regulated? | Learn More >
What happens when there's a leak? | Learn More >

Operator Training

Pursuant to statute,1 an owner or operator of a UST system must designate a Class A, a Class B and one or more Class C individuals, who must complete required operator training. As a service to the regulated community and to help ensure UST systems are properly managed, ADEQ provides required Class A/B training at no cost to owners and operators of UST systems.

Learn more about ADEQ's UST Operator Training | Learn More >

Leak Prevention (Noncorrective Action)

Leak prevention activities, also known as noncorrective actions, are proactive measures designed to prevent future releases. These include system upgrades, tank removals, baseline assessments and sampling to confirm a release. ADEQ provides financial assistance for these activities to eligible UST owners, operators and property owners through either the State Lead Noncorrective Action Program or the Tank Site Improvement Program.

Learn more about the State Lead Noncorrective Action Program | Learn More >
Learn more about the Tank Site Improvement Program | Learn More >

Cleanup (Corrective Action)

The activities necessary to investigate, analyze and conduct cleanup activities are called corrective actions.2 The UST Program provides compliance assistance and regulatory oversight for UST owners and operators who have had a release from their UST system. The program also assists property owners who voluntarily undertake corrective actions (these activities are often related to property re-development). In addition to regulatory and technical support, UST owners, operators and property owners may qualify for financial assistance for these activities through either the State Lead Corrective Action Program or the Preapproval Program.

Learn more about the State Lead Corrective Action Program | Learn More >
Learn more about the Preapproval Program | Learn More >

Inspections & Compliance

The UST Program conducts inspections at UST facilities, focusing on verifying leak detection equipment, spill containment, overfill protection and operator training. UST inspectors are available to help UST owners and operators understand the importance of system testing and maintenance activities that prevent releases from their UST systems. The UST Program provides compliance assistance to UST owners and operators about requirements for confirming a suspected release and for the initial response to a confirmed release. If the UST owner and operator fail to conduct adequate corrective action for their UST release within time frames required by federal and state regulations, the UST Program may initiate enforcement actions.

Learn more about UST compliance | Learn More >