In 1986 the State of Arizona adopted certain rules and timelines pertaining to Underground Storage Tanks (UST's). A storage tank and associated piping is defined as a UST if 10% or greater of the total volume is buried underground. As of December 1998, all UST's must have been removed, abandoned in place or upgraded to new tank standards. All new installations and upgrades must meet "New Tank Standards." These standards include tank system monthly volumetric reconciliation, overfill and spill protection, and release detection.
Before 1990, the University of Arizona (UA) owned and operated over 60 UST's statewide. These tanks were used to store fuels, waste oil and even pesticide tank mix rinsate. The fuels ranged from two grades of gasoline for automotive use and citrus farm frost fans to #2 diesel fuel used for heavy equipment and emergency generators. Tank size varied from 50 gallons up to 12,000 gallons. Currently the UA owns/operates only eight (8) UST's statewide. Over 50 have been removed and decommissioned. During removal, many tanks showed evidence of content release. Such a release could be caused by a one time product overfill or large surface spill of fuel, or a small chronic leak due to an impact or corrosion hole in the tank wall. If release evidence is determined through visual, olfactory or analytical testing the UST upon removal, now becomes a Leaking Underground Storage Tank (LUST). This designation places the tank into another regulatory category where the greatest concern is the protection of groundwater. Only about 25% of all removed UST's are considered clean extractions and closures.
Whenever feasible, Risk Management & Safety (RM&S) strongly recommends that all fuel storage be aboveground to minimize potential environmental impact. Tanks of this type are called Aboveground Storage Tanks or AST's. It is most environmentally sound to fuel emergency generators with natural gas when available. Installation of an AST on state property requires a permit from the Office of the State Fire Marshal. RM&S will assist departments with completion and submission of AST permit application.
For questions or assistance with AST's contact the Building Safety Officer, Jose Arizpe at 621-1572 or arizpe@email.arizona.edu. For questions or assistance with UST's contact the Environmental Safety Officer, Lloyd Wundrock at 621-1590 or lloydw@email.arizona.edu.
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