1. Release Detection Requirements for Underground Storage Tanks.

a.   Automatic Tank Gauges must provide a 0.2 gallon per hour leak test on all regulated tanks. A minimum of 1 passing test per month must be obtained from each tank.

b. Double Walled Underground storage tanks with interstitial sensors are required to have an annual function test and provide monthly condition status if sensors are the primary method of release detection.

2. Release Detection Requirements for Underground piping.

a. Pressurized piping with mechanical line leak detectors are required to have an annual volumetric line and leak detector test.

b. Mechanical line leak detectors must be able to restrict flow at a minimum leak rate of 3.0 gallons per hour.

c. At this time no annual volumetric line testing is required if electronic line leak detection is installed. However, it is strongly recommended that all electronic line leak detectors are tested at a minimum leak rate of 3.0 gallons per hour on an annual basis.

d. Double Walled Underground piping with interstitial sensors are required to have an annual function test and provide monthly condition status if sensors are the primary method of release detection.

e. Suction piping does not require testing if check valve is located at pump or dispenser. Suction piping with check valves located in or at tank must be tested every 3 years.

3. Cathodic Protection Requirements.

a. Cathodic protection testing is required every 3 years in Minnesota and annually in Wisconsin.

b. All testing must be performed by certified cathodic protection testers.