The EPA has released the results of the largest survey to-date on corrosion levels in underground storage tanks (USTs) containing diesel fuel -- and the results are staggering.
The research showed that 83 percent of the USTs studied exhibit moderate to severe corrosion.
Worse, only 25 percent of the owners of those tanks with corrosion were aware of it prior to the study.
That, according to Carolyn Hoskinson, Director of the EPA’s Office of Underground Storage Tanks (OUST)is troubling – because that corrosion “could result in an increased chance of releases of fuel to the environment and subsequent groundwater contamination.” Every UST operator’s nightmare.
The results of the survey, conducted by the renowned Battelle research institute, were not a surprise to us at Tanknology, as we performed all the fieldwork for this study as a partner of Battelle. Among other services, our TankCam® remote video inspection service provided the high-resolution images used in the analysis and the EPA’s final report.
In addition to the prevalence of corrosion in the diesel tanks inspected and the lack of awareness by owners, some ‘key takeaways’ the EPA identified include:
- Severe corrosion is not limited to the tanks themselves, but also prevalent in all the metal components of the fueling system. This is true in steel as well as fiberglass tanks.
- The condition is widespread – affecting diesel fueling systems in multiple regions of the country.
- There are approximately 100,000 federally-regulated diesel tanks in use in the US, according to PEI.
- Ethanol was present in 90 percent of the 42 tanks sampled, “suggesting cross contamination of diesel fuel with ethanol is likely the norm.”
- Tanknology technicians collected fuel samples from each tank system in the study and Battelle's testing against several fuel specifications and guidelines indicated that 'many UST systems may be storing fuel that is less clean and dry' than those standards intend.
- The presence of particulates and water in the fuel were “closest to being statistically predictive factors for metal corrosion,” though the EPA said the findings don’t necessarily signal causation.
What EPA OUST recommends:
- Visual inspection of fuel filters and tank system access points for signs of corrosion.
- Utilizing a UST service company (such as Tanknology) to further evaluate the extent of corrosion in the tank system. Tanknology could employ the same TankCamremote visual inspection service used in the EPA study to provide a clear look inside your tank system, capturing potential corrosion on video for further assessment.
- Repairing or replacing equipment to ensure proper functionality.
A PDF copy of the EPA study can be viewed and downloaded here, from our website, in the section, 'Learn More.'