What Happened?

In July 2016, the U.S. Environmental Protection Agency (EPA) created a massive report on the status of Underground Storage Tanks and possible leaking of contaminants.

What Did They Find?

They discovered that the corrosion of underground steel tanks (UST) containing diesel fuel is occurring at a high rate nationwide.  Specifically, 83% of moderate to severe corrosion of steel bottoms and walls and metal components of UST.

Why Is This Happening?

Although not confirmed, the Office of Underground Storage Tanks (OUST) believes the widespread corrosion of USTs storing diesel fuel may be caused by the changes in the national fuel supply starting in 2007.

What Changes?

In 2007, federal regulations required sulfur content of diesel fuel be reduced.  Lowering the sulfur in diesel necessitated changing the diesel formulations by adding components such as lubricity, cold-flow, and conductivity additives, plus corrosion inhibitors.  It also made it easier for bacteria and fungus to grow in fuel.

But Wait, There’s More…

The Energy Independence and Security Act of 2007 directed the EPA to require the volume of ethanol and biodiesel available for blending into petroleum-based fuels to increase significantly.  Plus, there was a trend among retailers to transition from storing midgrade gasoline to diesel when blender pumps reduced the need for storing all three grades of gasoline.

Why Is This a Big Deal?

Corrosion can result in equipment failure, tank system failure and underground water contamination.  Groundwater is a source of drinking water for half of the U.S. population.  As well, corrosion of some metal components can hinder their proper operation and possibly allow a release of fuel to occur unnoticed.

Speaking of Being Unnoticed

Because this is a relatively recent phenomenon, few owners (only 25%) are aware that corrosion, which could affect the operability of their UST system, could already be at an advanced stage.

What Can We Do?

  • Regularly monitoring and removing any water present in the UST.
  • Filtering fuel for water and particles before it is delivered into the UST or recirculating and filtering water and particles while stored.
  • Using biocides to kill, or other fuel treatments to disrupt existing or future microbial contamination.