Section 93.510. Leak detection requirements.

 

(1)   General.

(a) All new and existing underground tank systems used to store regulated substances shall be provided with a method of leak detection that complies with this section and s. ATCP 93.515 , except as exempted in par. (d) .

(b) The method of leak detection shall be approved in accordance with s. ATCP 93.130 .

(c) All monitoring equipment used to satisfy the requirements of this section shall be installed, calibrated, operated and maintained to perform as originally intended in accordance with the manufacturer's instructions and the department's approval, such as issued under s. ATCP 93.130 .

(d) Leak detection is not required for any of the following tanks:

1. Tanks which have a capacity of less than 1,100 gallons and which are located on farm premises or at private residences.

2. Tanks storing Class IIIB liquids that are neither petroleum nor CERCLA-listed products.

(e) If a tank system exhibits a continuing pattern of failing and then not failing leak detection testing, a precision tightness test shall be performed within 10 business days in accordance with s. ATCP 93.515 (4) , and if a tank system fails to pass that test, the site shall be assessed for the presence of a release in accordance with ss. ATCP 93.575 to 93.585 .

(2)   Annual calibration verification.

(a) The following equipment shall be verified by a qualified person every 12 months for the same degree of operability and capability as when the equipment was newly installed:

1. Equipment for measuring product levels that is used for manual tank gauging or statistical inventory reconciliation.

2. Automatic tank gauging equipment used for monthly monitoring, statistical inventory reconciliation or precision tightness testing.

3. Interstitial monitoring equipment.

4. Sensors used to detect leaks in tanks, lines or sumps.

(b) Under this subsection, a qualified person is a person certified by the equipment manufacturer as being trained in the operational characteristics of the equipment.

(c) Annual monitoring equipment certification shall be made on the department's underground tank system prevention and detection functionality verification form (ERS-10778) and shall be maintained onsite in accordance with s. ATCP 93.500 (9) (a) .

(3)   Leak detection for tanks.

(a) General .

1. Tanks shall be monitored at least every 30 days for leaks using one of the methods listed in s. ATCP 93.515 , except as provided in subd. 2.

2. Tanks that have a capacity of 1,000 gallons or less may use manual tank gauging conducted in accordance with s. ATCP 93.515 (3) as the sole means of leak detection provided it is performed weekly.

(b) Failed tests . If a passing test using monthly monitoring is not achieved for 2 consecutive months, a precision tightness test shall be performed within 10 business days in accordance with s. ATCP 93.515 (4) , and if a tank fails to pass that test, the site shall be assessed for the presence of a release in accordance with ss. ATCP 93.575 to 93.585 .

(c) Inconsistent results . The authorized agent or the department may require a precision tightness test to be performed where any of the following events occur:

1. A tank system is accumulating water for no apparent reason.

2. A leak detection method is providing erratic results.

3. A tank system is tested with multiple leak detection methods that show different results.

(d) Inventory control as leak detection . Tank systems may use monthly inventory control performed in accordance with s. ATCP 93.515 (2) as leak detection provided all of the following conditions are met:

1. The tank is 10 years old or less.

2. The tank has precision tank tightness testing conducted in accordance with s. ATCP 93.515 (4) at least once every 5 years from the date of installation until the tank is 10 years old.

3. The tank system has corrosion protection in accordance with s. ATCP 93.520 .

(4)   Leak detection for piping.

(a) Pressurized piping . Underground piping that conveys regulated substances under pressure shall comply with all of the following requirements unless all of the piping is visible:

1. The system shall be equipped with an automatic line leak detector in accordance with s. ATCP 93.515 (8) (b) .

2. Single-wall piping systems shall have at least one of the following leak detection methods:

a. An annual precision tightness test.

b. Monthly monitoring to the 0.2 gallon per hour rate.

3. Double-wall piping systems shall use one of the leak detection methods in subd. 2. , or statistical inventory reconciliation, or continuous interstitial monitoring.

4. If a passing test using monthly monitoring is not achieved for 2 consecutive months, a precision tightness test shall be performed within 10 business days in accordance with s. ATCP 93.515 (4) , and if the piping fails to pass that test, the site shall be assessed for the presence of a release in accordance with ss. ATCP 93.575 to 93.585 .

(b) Suction piping .

1. Piping which conveys regulated substances under suction and which is not entirely visible shall use one of the following leak detection methods, except as provided in subd. 2. :

a. A precision tightness test conducted at least every 3 years.

b. Interstitial monitoring.

2. Leak detection may be omitted for suction piping that meets all of the following requirements:

a. The below-grade piping operates at less than atmospheric pressure.

b. The below-grade piping is sloped so that the contents of the pipe will drain back into the storage tank if the suction is released.

c. Only 1 check valve is included in each suction line.

d. The check valve is visibly located directly below and as close as practical to the suction pump.

e. A method is provided that allows compliance with subd. 2. b. to d. to be readily observed or otherwise determined.

(c) Inventory control as leak detection. Piping connected to a tank using inventory control in accordance with sub. (3) (d) shall comply with one of the following:

1. Pressurized piping shall have leak detection complying with par. (a) .

2. Suction piping shall have leak detection complying with par. (b) .

CR 07-029 : cr. Register November 2008 No. 635 , eff. 2-1-09; CR 09-017 : am. (2) (title) and (c) Register July 2009 No. 643 , eff. 8-1-09; correction in (1) (a), (b), (c), (e), (2) (c), (3) (a) 1., 2., (b), (d) (intro.), 2., 3., (4) (a) 1., 4. made under s. 13.92 (4) (b) 7. , Stats., Register December 2011 No. 672 ; corrections in (1) (a) to (c), (e), (2) (c), (3) (a) 1., 2., (b), (d) (intro.), 2., 3., (4) (a) 1., 4. made under s. 13.92 (4) (b) 7. , Stats., Register October 2013 No. 694 .

Note

Form ERS-10778, Underground Tank System Prevention and Detection Functionality Verification, is available from the Bureau of Weights and Measures, PO Box 8911, Madison, WI 53708-8911, or at telephone [phone], or from the Bureau's Web site at https://datcp.wi.gov/Pages/Programs_Services/PetroleumHazStorageTanks.aspx . Microsoft Windows NT 6.1.7601 Service Pack 1 Under section section ATCP 93.500 (1) (a) , continuous electronic interstitial monitoring is generally required for all secondary containment installed on or after February 1, 2009. Microsoft Windows NT 6.1.7601 Service Pack 1 Under section s. ATCP 93.500 (1) (a) , continuous electronic interstitial monitoring is generally required for all secondary containment installed on or after February 1, 2009. Microsoft Windows NT 6.1.7601 Service Pack 1