Diesel UST Evaluations by TankCam® Inspection

A 2016 study by the EPA revealed that 83% of diesel UST systems have moderate to severe levels of corrosion.

Corrosion that is being described as the most aggressive and extensive ever known to permeate an Underground Storage Tank has been developing in recent years in diesel tanks through the country.

It is affecting steel as well as fiberglass tanks – attacking the metal components in the vapor space -- bungs, risers, caps, plugs, STP shafts, ball float assemblies and flapper valves.

  • ATG probe corrosion
  • Corroded filter housing in diesel dispenser
  • Flapper valve corrosion
  • Internal diesel tank corrosion
  • Centralizer coax flap corrosion
  • Severe bung corrosion
  • Corrosion inside diesel filter
  • Corroded flapper valve
  • Gas and diesel flapper valve comparison
  • STP corrosion
  • Severe STP housing corrosion
  • Severely corroded STP shaft
  • STP corrosion
  • Sludge in corroded dispenser containment
  • Diesel ATG riser corrosion
  • Corroded ball float in fiberglass tank
  • Internal steel tank corrosion
  • STP and bung corrosion in diesel fiberglass tank
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18


What's even more frightening – the EPA study found that 75% of operators who had these high levels of aggressive corrosion in their tanks were not aware of it.

Tanknology performed the fieldwork for this EPA study, using our TankCam® remote visual inspection system – the same system the EPA now recommends as a method for inspecting your diesel UST systems so that you know you're not among the 83 percent.

The TankCam video assessment does not require your tanks to be empty of fuel and it is performed remotely from aboveground – no one needs to enter your tank.

The inspection is highly detailed, as the technician captures high resolution images of all suspect conditions; corrosion or otherwise. The result is a digital video file, which details all the key components in the tank. The photos you see here were all captured in TankCam inspections.

To learn more, or discuss specific compliance needs for your site, call us today at 1-800-964-1250.

Learn More

Corroded pipes and sludge under diesel dispenser containment

Corroded filter housing inside diesel dispenser

Looking down the probe of an ATG riser reveals extreme corrosion

Corroded STP and bung in FRP tank

Major corrosion inside a steel diesel underground tank

At A Glance
Key findings of EPA's July 2016 Study on Corrosion in Diesel UST Systems
  • 83% of UST systems evaluated in the study exhibited moderate to severe corrosion.
  • Only 25% of the affected owner/operators were aware of the corrosion prior to the study.
  • 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.
  • Ethanol was present in 90% of the 42 tanks sampled, “suggesting cross contamination of diesel fuel with ethanol is likely the norm.”
  • Many UST systems may be storing fuel that is less “clean and dry” than those standards stipulate.
  • 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.

For more information, or to follow this issue as it evolves, see our Tanknology Blog.


Get a quote or moe information.

Upcoming Events

NACS/PEI  Oct 11-14, Las Vegas
POWERGEN  Dec 8-10, Orlando
UNITI Expo  Feb 9-11, Stuttgart
National Tanks  Sep 21-23, Pittsburg

Register for TANCS


Our customers have 24/7 Online Access
to key data related to their facilities.
Register for TANCS.

By using TANCS, you agree to our
Terms and Conditions.

Contact Us

Call 1-800-964-1250 today to discuss specific compliance needs for your site. Who are we? Learn more.

Careers for Veterans

If you are a Veteran, we invite you to learn about your next career with us.