ATCP 93.503 Note Note: The inventory verification specified in this section is not required to conform to the inventory control specifications in API 1621.

ATCP 93.503(2) (2) To verify and maintain the integrity and quantity of delivered products, product inventory verification shall be conducted monthly for the life of the tank system, and reconciled on a monthly basis, in the following manner:

ATCP 93.503(2)(a) (a) Inventory volume measurements for regulated substance inputs, withdrawals, and the amount still remaining in the tank are recorded each operating day.

ATCP 93.503(2)(b) (b) The equipment used is 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 93.503(2)(c) (c) The regulated substance inputs are reconciled with delivery receipts by measurement of the tank inventory volume before and after delivery. Where tanks are interconnected by a manifold, reconciliation may address all of the interconnected tanks as a group rather than as individual tanks.

ATCP 93.503(2)(d) (d) Product dispensing is metered and recorded in accordance with applicable requirements in ch. ATCP 92 for meter calibration or an accuracy of 6 cubic inches for every 5 gallons of product withdrawn.

ATCP 93.503(2)(e) (e) The measurement of any water level in the bottom of the tank is made to the nearest one-eighth of an inch at least once a month.

ATCP 93.503(3) (3) The reconciliation under sub. (2) shall be used to determine whether either of the following are indicated:

ATCP 93.503(3)(a) (a) A leak detection method has failed as indicated by an overall product loss for two consecutive months as addressed in s. ATCP 93.570 (4).

ATCP 93.503(3)(b) (b) Unauthorized product mixing has occurred, as indicated by an unexplained increase or decrease in product level and as addressed in ch. ATCP 94.

ATCP 93.503 Note Note: Where inventory control is used as the leak detection method, under s. ATCP 93.515 (2), the measurements and procedures followed there will satisfy the requirements for inventory verification in this section.

ATCP 93.503 Note Note: Where statistical inventory reconciliation is used as the leak detection method, under s. ATCP 93.515 (6), the same data may be used for the statistical inventory reconciliation and the inventory verification in this section, provided the requirements of the statistical inventory reconciliation vendor and of this section are both met, including the monthly reconciliation in this section.

ATCP 93.503 History History: CR 17-092: cr. Register October 2019 No. 766, eff. 11-1-19.

ATCP 93.505 ATCP 93.505 Spill and overfill prevention.

ATCP 93.505(1) (1) General.

ATCP 93.505(1)(a) (a) Prior to delivery, the operator of the fuel delivery equipment that is transferring the product shall ensure that the volume available in the tank is greater than the volume of product to be transferred to the tank.

ATCP 93.505(1)(b) (b) The transfer operation shall be monitored constantly by the operator of the delivery equipment so as to prevent overfilling and spilling.

ATCP 93.505(2) (2) Equipment. All underground storage tank systems, whether new or existing, shall meet all of the following requirements except par. (a) 1. a. does not apply to containment that was installed before February 1, 2009, and par. (a) 3. does not apply to containment that was installed before November 1, 2019:

ATCP 93.505(2)(a) (a) Spill prevention. A liquid-tight containment basin that meets all of the following requirements shall be provided on top of the tank, where connections are made for product fill piping:

ATCP 93.505(2)(a)1. 1.

ATCP 93.505(2)(a)1.a. a. The basin shall have a capacity of at least five gallons.

ATCP 93.505(2)(a)1.b. b. The basin shall be fabricated and installed in a manner that prevents release of liquids.

ATCP 93.505(2)(a)2. 2. The basin shall be equipped with either a drain system that directs spilled product into the tank or a mechanism to pump product out of the basin.

ATCP 93.505(2)(a)3. 3.

ATCP 93.505(2)(a)3.a. a. The basin shall be tested for leaks hydrostatically at installation in accordance with any manufacturer’s instructions, and the adopted standard PEI RP 1200, except as provided in subd. 3. b.

ATCP 93.505(2)(a)3.b. b. The testing in subd. 3. a. may be omitted for a spill containment basin that has continuous electronic pressure, vacuum, liquid-filled interstitial monitoring in addition to double-wall construction, if the monitoring system is tested at installation to verify that it operates in accordance with the manufacturer’s specifications.

ATCP 93.505(2)(b) (b) Overfill prevention.

ATCP 93.505(2)(b)1. 1. Overfill prevention equipment shall be provided that will operate as follows unless approved otherwise in writing by the department:

ATCP 93.505(2)(b)1.a. a. Alert the transfer operator when the tank is no more than 90 percent full by triggering an audible and visual high-level alarm.