tanks (USTs), the US Environmental Protection Agency (EPA) found moderate or severe corrosion that could affect metal components inside both steel and fiberglass underground tank systems. Corrosion inside USTs can cause equipment failure by preventing proper operation of release detection and prevention equipment. If left unchecked, corrosion could cause UST system failures and releases, which could lead to groundwater contamination.
Beginning around 2007, UST owners reported to servicing companies new incidents of severe and rapid corrosion of internal metal components of tanks storing diesel fuel. These reports usually described severe corrosion of equipment in upper portions of UST systems in the regions generally not submerged in fuel. Prior to 2007, a corrosion risk in diesel fuel tanks was considered minor and, if it occurred, appeared in the wetted, or lower, portion of the tank. . . .
EPA began working on this research in 2014 to understand how serious and widespread the metal corrosion problem could be. EPA’s report shows that 35 of 42—83%—of the USTs studied exhibited moderate or severe corrosion, but less than 25% of owners were aware of corrosion prior to the internal inspection. . . .
