• UST regulation removes the deferral for UST systems that store fuel solely for use by emergency power generators, field-constructed tanks, and airport hydrant fueling systems.

The 2015 underground storage tank (UST) regulation removes the deferral for UST systems that store fuel solely for use by:

• Emergency power generators (emergency generator tanks);
• Field-constructed tanks; and
• Airport hydrant fueling systems.

Emergency generator tanks

These UST systems must meet release detection requirements as follows:

• Systems installed on or before October 13, 2015, have three years to use any of the applicable release detection methods.
• Systems installed between October 13, 2015, and April 11, 2016, must use any of the applicable release detection methods listed above at installation.
• Systems installed or replaced after April 11, 2016, must meet secondary containment requirements with interstitial monitoring.

Field-constructed tanks (FCTs) and airport hydrant systems (AHSs)

Owners and operators must meet release detection requirements. Field-constructed tanks (FCTs) and airport hydrant systems (AHSs) installed on or before October 13, 2015, must have release detection by October 13, 2018. FCTs and AHSs installed after October 13, 2015, must meet all release detection requirements at installation. Tanks and some piping installed after April 11, 2016, must be secondarily contained and use interstitial monitoring. Owners and operators may use single walled piping when installing or replacing piping associated with UST systems with FCTs greater than 50,000 gallons and piping associated with AHSs.