The Underground Storage Tank (UST) Program was launched to minimize and prevent environmental damage, by requiring owners and operators of UST systems to install, verify functionality of, and maintain leak detecting equipment on their UST systems. The purpose of the UST program is to protect public health and safety, the environment, and the waters of the state, which you use for drinking, recreational purposes, crop irrigation, and more, from discharges and releases of hazardous substances from USTs. A UST is a tank or combination of tanks and piping, located beneath the surface of the ground, that stores hazardous chemicals.