Back in 2015, some UST categories were move from deferred to ‘partially excluded’ and some systems are now regulated by the EPA. The partially excluded UST systems and tanks include the following:
- Systems that store radioactive substances that are regulated by the Atomic Energy Act of 1954.
- Systems that are connected to a generator system under a nuclear power facility that is licensed by the Nuclear Regulatory Commission (NRC). These tanks should also fulfill NRC requirements pertaining to their design and quality.
- Tanks that are used to contain and treat waste water and which are not excluded from regulations.
The systems that are partially excluded from the regulation have to fulfill installation criteria mentioned in subpart A. This also includes the release and corrective actions that are mentioned in subpart F.
UST tanks that are not deferred any more by the regulation include the following:
- Storage tanks that are present aboveground and part of a system that is attributed to airport hydrant fuel.
- UST systems with field constructed tanks.
- UST systems that are used to store fuel that is used by emergency power generators.