(a) All new tanks shall be constructed and designed to provide enough space between tanks to allow safe access for maintenance, inspection, testing, and repair.

(b) Foundations for new tanks shall be designed to support the tank, maintain the tank level, and drain fluid away from the tank, including fluids that may leak from the tank. The sub-base of the foundation shall include an impermeable barrier designed to prevent downward fluid migration and to allow leaks to drain away from the tank and be detected by visual inspection or through the use of a leak detection sensor, as each particular instance may require. The foundation base shall be made of material that provides for support and drainage away from the tank.

(c) When a tank bottom is replaced, a leak detection system shall be installed and properly maintained that will either:

(d) The Supervisor or district deputy may require a tank bottom leak detection system for any tank with a foundation that does not have an impermeable barrier after considering such factors as the age of the tank, fluid service, and proximity to groundwater.