Corrosion of Internal Components in USTs Storing Diesel Fuel
In 2016, EPA did a study of 42 USTs storing diesel fuel and found that 83 percent exhibited moderate or severe corrosion of metal components inside the tank system. EPA’s research built on a prior industry study by the Clean Diesel Fuel Alliance completed in 2012, and previous research by EPA’s Office of Research and Development.
Neither EPA nor industry can project the actual percentage of USTs storing diesel that are affected by corrosion nationwide. However, this could be a widespread and potentially significant problem for owners of underground tanks storing diesel fuel. Since corrosion may potentially lead to releases in the environment and many UST owners may be unaware their systems are affected, EPA developed the Notice of Corrosion Risks in Underground Storage Tanks Storing Diesel Fuel in July 2016 to alert owners.
The corrosion may cause metal components inside both steel and fiberglass UST systems to corrode. This can possibly shorten the lifespan or affect the serviceability of components, including limiting the movement of floats on automatic tank gauging systems, operability of mechanical devices designed to prevent the chance of overfilling the tank, or ability of shear valves to shut off flow of product in the event of a release. Corrosion may cause dispenser filters to clog and be replaced more frequently and could potentially limit the proper functionality of equipment designed to test for leaks in fuel product lines.
EPA continues to coordinate with industry to monitor and minimize risks from corrosion. If you suspect corrosion of metal components in your tanks that store diesel fuel, EPA’s July 2016 Notice of Corrosion Risks in Underground Storage Tanks Storing Diesel Fuel provides guidance. In addition, several organizations developed documents that suggest practices to maintain USTs storing diesel fuel. These industry documents contain other research, practices, technologies, or treatments to minimize the risk of release of diesel fuel from underground tanks. EPA recommends you access these resources for more information about minimizing the risk of corrosion in USTs storing diesel fuel.
- Transportation Energy Institute: Diesel Fuel Quality Council – Diesel Storage Tanks: Industry Practices to Minimize Degradation and Improve Fuel Quality (PDF) March 2021.
- Coordinating Research Council
- ASTM D6469 – Standard Guide for Microbial Contamination in Fuels and Fuel Systems (available for purchase).