Corrosion of underground steel tanks containing diesel fuel is possibly occurring at a high rate, according to a study released by EPA’s Office of Underground Storage Tanks (OUST). While the study is limited—covering only 42 “diverse” UST systems nationwide—and also makes use of anecdotal reports from UST operators, the OUST found a remarkably high percentage (83 percent) of moderate to severe corrosion of steel bottoms and walls and metal components of USTs.
The OUST believes widespread corrosion of USTs storing diesel fuel may be a relatively recent phenomenon caused by changes in the national fuel supply beginning about 2007. Corrosion can result in leaks to the environment and also increases servicing and equipment maintenance costs for UST system owners. OUST’s main recommendation is that tank owners visually inspect USTs storing diesel as part of routine monitoring.