E-15 Compatibility

Written by: Brian Pottebaum, Director of Training Services


Compatible is defined by the EPA as the ability of two or more substances to maintain their respective physical and chemical properties upon contact with one another for the design life of the tank system under conditions likely to be encountered in the UST.

Compatibility has been part of federal regulations since 1988, requiring UST systems to be made of or lined with a material that is compatible with the substance or product being stored. Most recently, this is targeting renewable fuels containing higher blends of ethanol and biodiesels.

Energy Policy Act of 2005

The Energy Policy Act of 2005 was signed into law on August 8, 2005, calling for the development of grant programs, demonstration and testing initiatives, and tax incentives that promote alternative fuels and advanced vehicles production and use.

As a result of the Energy Policy Act, EPA published revised UST regulations in year 2015. These revisions:

  • Added Secondary containment requirements for new and replaced tanks and piping,
  • Added operator training requirements,
  • Added periodic operation and maintenance requirements for UST systems,
  • Added requirements to ensure UST system compatibility before storing certain biofuel blends

(later revised to include specific requirements for UST System compatibility, E15 Dispenser Labeling, Marketing E15 in summer months, and a waiver for light-duty vehicles 2001 and newer),

  • Removed past deferrals for emergency generator tanks, field constructed tanks, and airport hydrant systems, and
  • Added requirements for UST System compatibility, E15 Dispenser Labeling, Marketing E15 in summer months, and a waiver for light-duty vehicles 2001 and newer.

This new regulation also revised the definition of compatibility to include specific notification requirements as well as documentation of system compatibility with regulated substances containing greater than 10 percent Ethanol, greater than 20 percent biodiesel, or any other regulated substance identified by implementing agency.

Records of compatibility must be maintained by the owner for as long as the UST system is used to store the regulated substance.

Why You Should Care

Components that are NOT compatible with the substances being stored and dispensed through the UST system will cause deterioration and reduce the fuel quality. Ultimately, component deterioration will lead to system failure and could result in a spill or release of product to the environment.

How To Comply

At least 30 days prior to filling the tanks with a product exceeding E10 or B20, you must demonstrate compatibility with the receiving UST system. This will require the owner, and in some situations a service contractor, to review the system components and technical documents certifying that the system is listed by the respective manufacturers or an approved independent testing laboratory (such as UL) for use with these regulated substances.

This notification must be filed with the regulatory agency 30 days before introducing the regulated substance to the UST system.  This notification must also be provided to the tank insurance provider, such as PMMIC, before the substance is placed in the tank. This includes E15.

Are You Switching to E-15?

Do not make the mistake of switching product in your tanks without taking the proper steps in documenting compatibility and preliminary notification to all interested parties. Not taking these steps could result in regulatory violations and insurance policy complications.

If you have questions regarding a potential switch of product that could affect your insurance policy, please contact our office.

2894 106th St. Ste. 220 Urbandale, Iowa 50323