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UST Forms and Guidance

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If you have trouble with any of the links, email us at: ask.tdec@tn.gov

Blended Fuels    

Prior to putting a UST system designed to store ethanol blended fuels greater than 10% ethanol or a blend of greater than 20% of biodiesel into service, tank owners must complete and submit an Equipment Compatibility Checklist (CN-1285) and a Statement Of Compatibility (CN-1283) indicating the UST system components will be compatible with the product stored.   

Ethanol blended fuels are designated by the amount of ethanol the fuel contains. A fuel labeled as E-85 contains 85% ethyl alcohol and 15% gasoline. E-10 contains only 10% ethyl alcohol and 90% gasoline. Biodiesel blends are designated by the amount of biodiesel the fuel contains. A fuel labeled as B-20 contains 20% biodiesel and 80% diesel. With all the interest in alternative fuels, it is important to remember that not all components of most UST systems designed to contain and dispense petroleum products, may be compatible with alternative fuels.    

The Division is charged with the safe storage of petroleum products (TCA 68-215-102), which includes blended fuels, under the regulatory definition of petroleum. UST systems which store blended fuels are subject to all UST requirements. The Division is concerned about the compatibility of blended fuels with UST system components designed to store much higher percentages of petroleum. UST system components can be adversely impacted by interaction with blended fuels. 

Dispenser Options    

Dispensers are a critical component of the UST fuel system.  Dispenser manufacturers sell dispensers that they certify to be fully compatible with blended fuels. This is the option the Division recommends for use with blended fuels.    

If a tank owner wishes to use an existing dispenser with blended fuels, the installer must certify that all the listed dispenser components in Section 2 of the Ethanol Equipment Compatibility Checklist (CN-1285) are certified by the manufacturer or UL Marked as compatible for blended fuel, by completing the checklist. If all the components are marked “Yes” then the dispenser is considered compatible with blended fuels.    

If any of the listed components cannot be verified as either UL Marked or certified by the manufacturer as compatible, then the dispenser is not considered compatible with e-blended fuels. Dispensers that are not certified by the manufacturer or UL Marked as compatible for E-blend fuel must be inspected daily for leaks or equipment failure by using the Dispenser Daily Inspection Form (CN-1284). One form must be used for each dispenser or MPD (multi-product dispenser) connected to a blended fuel tank. These records must be retained on site for a period of one year.    

For more about Alternative Fuels, you can visit the EPA website: Emerging Fuels and Underground Storage Tanks (USTs)

The Division has located several documents that describe some Best Management Practices (BMPs) or are good resources.

This Page Last Updated: June 14, 2023 at 9:29 AM