Underground Storage Tank Releases in Arizona: Causes, Extent, and Remediation

There are over 17,000 underground storage tank (UST) systems located at over 6000 facilities registered with the state of Arizona. Although UST systems occur throughout the state, the majority occur in the Phoenix and Tucson areas. As of September, 1988, 425 releases from UST systems have been reported to the state. 1 Products released include gasoline, diesel, waste oil, aviation fuels, and kerosene. UST system leaks have occurred due to overfill, product line failure, tank failure, and spillage during tank removal. As expected, the majority of UST system leaks have occurred in the Phoenix and Tucson areas. However, significant numbers of leaks have also occurred in other portions of the state.