Chapter ATCP 93

ATCP 93.510(3)(c)2. 2. A leak detection method is providing erratic results.

ATCP 93.510(3)(c)3. 3. A tank system is tested with multiple leak detection methods that show different results.

ATCP 93.510(3)(d) (d) Inventory control as leak detection. Tank systems installed prior to February 1, 2009, 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:

ATCP 93.510(3)(d)1. 1. The tank is 10 years old or less.

ATCP 93.510(3)(d)2. 2. The tank has precision tank tightness testing performed 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.

ATCP 93.510(3)(d)3. 3. The tank system has corrosion protection in accordance with s. ATCP 93.520.

ATCP 93.510(4) (4) Leak detection for piping.

ATCP 93.510(4)(a) (a) Pressurized piping. Underground piping that conveys regulated substances under pressure shall comply with all of the following requirements:

ATCP 93.510(4)(a)1. 1. The system shall be equipped with an automatic line leak detector in accordance with s. ATCP 93.515 (8) (b).

ATCP 93.510(4)(a)2. 2. Single-wall piping systems shall have at least one of the following leak detection methods:

ATCP 93.510(4)(a)2.a. a. An annual precision tightness test in accordance with s. ATCP 93.515 (4).

ATCP 93.510(4)(a)2.b. b. Monthly monitoring to the 0.2 gallon per hour rate.

ATCP 93.510(4)(a)3. 3. Double-wall piping systems shall use one of the leak detection methods in subd. 2., or statistical inventory reconciliation, or continuous interstitial monitoring, except as provided in s. ATCP 93.500 (1) (a).

ATCP 93.510 Note Note: Under s. ATCP 93.500 (1) (a), continuous electronic interstitial monitoring is generally required for all secondary containment installed on or after February 1, 2009.

ATCP 93.510(4)(a)4. 4. If a passing test using monthly monitoring is not achieved, the site shall be assessed for the presence of a release in accordance with ss. ATCP 93.575 to 93.585.

ATCP 93.510(4)(b) (b) Suction piping.

ATCP 93.510(4)(b)1. 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.:

ATCP 93.510(4)(b)1.a. a. A precision tightness test performed in accordance with s. ATCP 93.515 (4) at least every three years.

ATCP 93.510(4)(b)1.b. b. Interstitial monitoring.

ATCP 93.510(4)(b)2. 2. Leak detection may be omitted for suction piping that meets all of the following requirements:

ATCP 93.510(4)(b)2.a. a. The below-grade piping operates at less than atmospheric pressure.

ATCP 93.510(4)(b)2.b. 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.

ATCP 93.510(4)(b)2.c. c. Only one check valve is included in each suction line.

ATCP 93.510(4)(b)2.d. d. The check valve is visibly located directly below and as close as practical to the suction pump.

ATCP 93.510(4)(b)2.e. e. A method is provided that allows compliance with subd. 2. b. to d. to be readily observed or otherwise determined.

ATCP 93.510(4)(c) (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:

ATCP 93.510(4)(c)1. 1. Pressurized piping shall have leak detection complying with par. (a).

ATCP 93.510(4)(c)2. 2. Suction piping shall have leak detection complying with par. (b).

ATCP 93.510 History History: CR 17-092: cr. Register October 2019 No. 766, eff. 11-1-19; correction in (3) (d) (intro.) made under s. 35.17, Stats., Register October 2019 No. 766.

ATCP 93.515 ATCP 93.515 Leak detection methods.

ATCP 93.515(1) (1) General.

ATCP 93.515(1)(a) (a) Leak detection methods for tank systems shall meet the requirements of this section.

ATCP 93.515(1)(b) (b) The leak detection test information reports submitted to the department, or maintained on site as required in s. ATCP 93.500 (9), shall include at least all of the following:

ATCP 93.515(1)(b)1. 1. Site information including the name of the business, the street address, and the municipality in which the site is located.

ATCP 93.515(1)(b)2. 2. Tank system information including the department-assigned tank identification number, the site identification number designated by the owner or operator, the tank capacity, the product in the tank, the type of pipe system, and whether there are pipe manifolds in the tank system.

ATCP 93.515(1)(b)3. 3. Test method information including the name of the method or equipment used, the material approval number as issued under s. ATCP 93.130, the date the test was performed, the threshold value used to declare a leak, the rate of volumetric change, whether the final result was a pass or fail, and the name and certification of the technician performing the test.

ATCP 93.515(2) (2) Inventory control.

ATCP 93.515(2)(a) (a) General methodology. Inventory control that is used as the leak detection method shall be conducted in accordance with API 1621 and with this subsection.

ATCP 93.515(2)(b) (b) Prescriptive requirements. Product inventory control shall be conducted monthly and reconciled to detect a leak rate of at least 0.5 percent of throughput on a monthly basis, in the following manner:

ATCP 93.515 Note Note: A leak rate of 0.5 percent is equal to 5 gallons out of every 1,000 gallons of throughput.

ATCP 93.515(2)(b)1. 1. Inventory volume measurements for inputs, withdrawals, and the amount still remaining in the tank shall be recorded each operating day.

ATCP 93.515(2)(b)2. 2. The equipment used shall be capable of measuring the level of product over the full range of the tank’s height to the nearest one-eighth of an inch.

ATCP 93.515(2)(b)3. 3.

ATCP 93.515(2)(b)3.a. a. The inputs shall be reconciled with delivery receipts by measurement of the tank inventory volume before and after delivery.

ATCP 93.515(2)(b)3.b. b. Where tanks are interconnected by a manifold, reconciliation may address all of the interconnected tanks as a group rather than as individual tanks.

ATCP 93.515(2)(b)4. 4. The measurement of any water level in the bottom of the tank shall be electronically or manually gauged to the nearest one-eighth of an inch at least once a month and recorded.

ATCP 93.515(2)(c) (c) Product losses. Tank systems that exceed the losses allowed under par. (b) for 2 consecutive months shall follow the requirements in ss. ATCP 93.575 to 93.585 for assessing and responding to a release.

ATCP 93.515(2)(d) (d) Precision tightness test. A precision tightness test shall be performed in accordance with sub. (4) within 10 business days of notification from the authorized agent or the department for any of the following reasons:

ATCP 93.515(2)(d)1. 1. Failure to provide monthly inventory control data for the past 12 months.

ATCP 93.515(2)(d)2. 2. Incomplete or inconsistent data entry reflected during any 2 months of data entry out of the most recent 3 months of inventory control record keeping.

ATCP 93.515(3) (3) Manual tank gauging.

ATCP 93.515(3)(a) (a) Where allowed.

ATCP 93.515(3)(a)1. 1. Manual tank gauging may be used as the sole method of leak detection for tanks that have a capacity of 1,000 gallons or less for the life of the tank.

ATCP 93.515(3)(a)2. 2. For tanks that have a capacity of more than 1,000 gallons to 2,000 gallons, manual tank gauging may be used if all of the following conditions are met:

ATCP 93.515(3)(a)2.a. a. The tank system has a precision tightness test performed in accordance with sub. (4) at least once every 5 years from the date of installation until the tank is ten years old.

ATCP 93.515(3)(a)2.b. b. The tank is less than 10 years old.

ATCP 93.515(3)(a)2.c. c. The piping either receives an annual precision tightness test or has electronic line leak detection testing, and this tightness test or leak detection testing is performed in accordance with the capabilities specified in s. ATCP 93.130 (3) (b).

ATCP 93.515(3)(a)3. 3. Tanks which have a capacity of more than 1,000 gallons to 2,000 gallons and which are more than 10 years old shall be provided with monthly monitoring in accordance with sub. (5), (6), or (7).

ATCP 93.515(3)(a)4. 4. Tanks that have a capacity of more than 2,000 gallons may not use manual tank gauging as the method of required leak detection.

ATCP 93.515(3)(b) (b) Manual tank gauging procedures. Manual tank gauging shall meet all of the following requirements:

ATCP 93.515(3)(b)1. 1. Liquid level measurements shall be taken with a gauge stick that is marked to measure the liquid to the nearest one-eighth of an inch over the full range of the tank’s height.

ATCP 93.515(3)(b)2. 2. Tank liquid level measurements shall be taken at the beginning and ending of the test duration periods given in Table 93.515, during which no liquid may be added to or removed from the tank and shall be based on the average of 2 stick readings taken at both the beginning and ending of the period.

ATCP 93.515(3)(b)3. 3. A leak is suspected and subject to the requirements of ss. ATCP 93.575 to 93.585 if the variation between beginning and ending measurements exceeds the weekly or monthly standards in Table 93.515.

Table 93.515

1 Requires precision tightness testing every 5 years. This method is only allowed until the tank is 10 years old.

ATCP 93.515(4) (4) Precision tightness testing.

ATCP 93.515(4)(a) (a) Precision tightness testing shall be conducted in one of the following ways:

ATCP 93.515(4)(a)1. 1. By a certified tank system tightness tester, using methods approved under s. ATCP 93.130 to perform precision tightness testing for tanks or piping.

ATCP 93.515 Note Note: The approval criteria in s. ATCP 93.130 include capability of detecting a leak rate of 0.1 gallons per hour.

ATCP 93.515(4)(a)2. 2. With permanently installed leak detection equipment as approved under s. ATCP 93.130 to perform precision tightness testing for tanks or piping.

ATCP 93.515(4)(b) (b) Where a certified tank system tightness tester is used, the tester shall include the date and the beginning and end times in the test results report.

ATCP 93.515(4)(c) (c) Precision tightness testing of double-wall underground product piping shall include testing of both the inner and outer wall.

ATCP 93.515(4)(d) (d) Precision tightness testing shall be recorded on the department’s tank precision tightness testing form, TR-WM-152, or line tightness testing form, TR-WM-125, as applicable and shall be maintained onsite in accordance with s. ATCP 93.500 (9) (a). Alternative forms may be used with the permission of the department.

ATCP 93.515(5) (5) Automatic tank gauging. Automatic tank gauging shall meet all of the following requirements:

ATCP 93.515(5)(a) (a)

ATCP 93.515(5)(a)1. 1. No more than 30 days may elapse between monthly monitoring tests using an automatic tank gauge.

ATCP 93.515(5)(a)2. 2. Monthly monitoring tests shall have the capabilities specified in s. ATCP 93.130 (3) (b).

ATCP 93.515(5)(a)3. 3. An automatic tank gauge shall be placed in the center of the tank and no closer than 12 inches from the fill pipe and the submersible pump.

ATCP 93.515(5)(b) (b) Automatic tank gauges shall be provided with a printer that provides at least all of the following information:

ATCP 93.515(5)(b)1. 1. The starting date and time and ending date and time of the test.

ATCP 93.515(5)(b)2. 2. The volume of liquid in the tank during the test.

ATCP 93.515(5)(b)3. 3. The measured leak rate in gallons per hour and whether this leak rate indicates a pass or a fail.

ATCP 93.515(5)(b)4. 4. The specific identification of the tank, associated piping, or sumps used for interstitial monitoring that are being tested.

ATCP 93.515 Note Note: See s. ATCP 93.130 (3) (b) 1. for approval requirements for automatic tank gauges.

ATCP 93.515(5)(c) (c) Automatic tank gauges shall be programmed to provide an audible and visual alarm in the event of a tank or line test failure, a periodic monthly tank or line test not performed within a 30-day interval, or a tank or line interstitial sensor actuation. Manual operator action shall be needed to silence the alarm.

ATCP 93.515(6) (6) Statistical inventory reconciliation.

ATCP 93.515(6)(a) (a) Leak detection methods based on the application of statistical principles to inventory data shall meet the requirements of 40 CFR § 280.43 (h) including:

ATCP 93.515(6)(a)1. 1. Report a quantitative result with a calculated leak rate;

ATCP 93.515(6)(a)2. 2. Be capable of detecting a leak rate of 0.2 gallon per hour or a release of 150 gallons within 30 days; and