What Is An Underground Storage Tank (UST) System?
An underground storage tank (UST) is either a single tank or a combination of multiple tanks which are interconnected with underground pipes. Most of the product volume contained in the tanks is underground in those pipes.
A UST system is made up of 3 parts:
- The tank
- The underground pipe network
- Underground ancillary equipment
There are basically 4 different types of USTs namely:
- Steel or aluminum tanks – these are made in compliance with the Steel Tank Institute in the US
- Composite overwrapped metal tanks – these are made of either aluminum or steel and feature a carbon fiber of plastic compound which is wrapped around a metal cylinder.
- Composite tanks with metal liners – these are made from composite material, fiberglass or carbon fiber and feature a metal liner.
- Composite tanks with carbon fibers – these carbon fiber tanks are lined with polymer.
Who Regulates UST System?Back in 1984, the EPA in the US was instructed to create regulations that can help facilities regulate the use of USTs. This was an important development since petroleum releases are difficult and expensive to clean up. It is less costly to prevent releases that can destroy the environment or jeopardize human health and life. The new regulations gave approved state programs authority over UST systems. States may have their own requirements which may be stricter than federal regulations. To ensure your systems remain compliant, contact your local regulatory agency to learn about any special requirements you may have overlooked. In case your UST systems are located in Indian country, you need to get in touch with the EPA regional UST program office. An ounce of prevention is worth a pound of cure in this case.
Are Above Ground Storage Tanks Regulated?Only those aboveground storage tanks (ASTs) or bulk storage containers meet the definition of an underground storage tank (UST) that are covered by UST regulations. An AST can contain about 55 gal. or more. It may be either above ground, bunkered, buried partially or completely underground. Most of these tanks have to meet Spill, Prevention, Control and Countermeasure (SPCC) requirements. These are also known as 40 CFR Part 112 requirements.
How Do You Close Tanks Safely?Underground storage tanks (UST) systems that are operational on or after December 22nd, 1998 should be closed according to certain requirements. The 40 CFR 280.70 closure requirements can be used to close these tanks permanently or temporarily. In case you want to close a UST system permanently, here is what you need to be aware of:
- The implementing agency should be notified at least 30 days before the UST is to be closed.
- If any contamination is present around the system, corrective action should be taken beforehand. This can be determined easily if you keep a record for 3 years of the actions taken to detect the presence of contamination. The record can then just be mailed to the agency.
- The UST should either be left underground or removed. In either of these cases, the tank should be emptied and cleaned to ensure no chemicals, sludge and vapors remain. This should be done by trained professionals who understand the hazards of this task. If the UST is to be left underground it should be filled with an inactive solid or it should be closed off in a manner that is agency approved.