The Underground Storage Tank (UST) program was created in 1985 to help prevent contamination caused by leaking tanks. Tank owners and operators must comply with state rules for USTs. The goal of the UST Program is to protect human health and the environment by preventing releases of petroleum and hazardous substances from UST systems. The release of these regulated products into the environment threatens groundwater resources and can cause explosive vapors to seep into confined spaces and occupied dwellings.