LG 116 - Regulation of Compartmental Underground Storage Tanks (UST)

May 1, 1991

To: Local Agencies

Questions have arisen recently concerning the regulation of compartmental underground storage tanks. It is the State Board's policy to treat each compartment containing a hazardous substance as an individual UST if it is hydraulically separated from the other compartment(s). For example: if an UST has three compartments and two of them are hydraulically linked – the entire configuration is then comprised of two USTs and permits are required for each. The same logic is applicable to other compartmentalized situations.

The term "hydraulically linked" means that the compartments contain the same substance and share withdrawal pipe(s).

When a compartment is permitted as a separate UST, it follows that a state surcharge fee is assessed on each UST.

Sincerely,

[Original signed by:]

Mike McDonald, Manager
Underground Storage Tank Program