EPA biofuel storage rule marks 'new round' of federal requirements

EPA published the proposed UST rule, which would apply to tanks holding ethanol-gasoline blends above 10% ethanol (E10) and "diesel containing an amount of biodiesel yet to be determined."

The agency plans to release its final rule in "early 2011," EPA spokeswoman Tisha Peteway said in an e-mailed response to questions.

New storage regulations are part of a series of steps that must be taken following EPA's approval of E15 for model year 2007 and newer conventional cars and light trucks. Other federal and state changes that need to be made before E15 becomes commercially viable include alterations to reformulated gasoline and detergent additive regulations, as well as RVP allowance, fuel rating and labeling requirements.

"As the US moves toward an increased use of biofuels, such as ethanol and biodiesel, compliance with the UST compatibility requirement becomes even more important, since ethanol and biodiesel blends can compromise the integrity of some UST system materials," the agency said.

As of March, there were about 607,000 regulated USTs at 221,000 facilities nationwide, according to EPA. "Because the typical lifespan of an underground storage tank is about 30 years, most UST systems currently in use are likely to contain components that were not designed to store ethanol blends beyond 10%," said the agency.

EPA said it is "aware of material compatibility concerns" with UST systems holding higher ethanol blends such as E85 and that "many tank owners" storing E85 either had to install all new equipment to handle that product or made other upgrades.

While independent testing company Underwriters Laboratories does certify some UST components for more ethanol, "many UST system components in use today, with the exception of most tanks and piping, have not been tested by UL for compatibility," said EPA.

On biodiesel, the agency said there is no UST equipment that has a UL listing for biodiesel blends, but that UL has stated blends up to 5% (B5) do not require a special UL listing. There are retailers storing biodiesel blends of B2-B99 in the US, noted EPA.