Waste Programs Division

What is an Underground Storage Tank System?

An underground storage tank (UST) system is a tank and any underground piping connected to the tank that has at least 10 percent of its combined volume underground. Federal and state UST regulations apply only to underground tanks and piping storing either petroleum1 or certain hazardous substances. Those with sites containing regulated USTs 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).

ADEQ's UST program collaborates with UST owners and operators, along with interested stakeholders, to prevent, identify and clean up releases into the environment. In addition to conducting periodic inspections and assisting owners and operators in complying with applicable state and federal regulations, the program provides financial assistance to eligible UST owners, operators and property owners to upgrade or remove USTs and conduct environmental cleanup.

What are UST releases? | Learn More >
Which USTs are regulated? | Learn More >
UST program overview | Learn More >