Wisconsin Legislature: ATCP 93.410(10)

4. Tank construction and marking shall comply with ss. ATCP 93.250 and 93.400 (7).

(b) Tanks used in recovery systems that pump free product at the rate of less than 60 gallons per week shall be constructed and marked in accordance with ss. ATCP 93.250 and 93.400 (7).

History: CR 17-092: cr. Register October 2019 No. 766, eff. 11-1-19; correction in (5) (b) 2. made under s. 13.92 (4) (b) 14., Stats., and correction in (8) (c) 1. made under s. 35.17, Stats., Register October 2019 No. 766.

ATCP 93.410 Spill and overfill prevention.

(1)

(a) All aboveground storage tanks, whether new or existing, shall have a means of overfill prevention which consists of either a visual gauge, an audible or visual alarm, or a pump shutdown that activates at 90 percent of the tank’s capacity, and which complies with any other applicable requirements in this section.

(b) Prior to delivery, the operator of the product 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.

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

(3) Equipment shall be clearly marked so visual and audible warning signals are recognizable to the delivery person.

(4) Spill and overflow prevention equipment shall be maintained to work as originally designed and installed.

(5) The fill opening shall be separate from the vent opening.

(6)

(a) All aboveground storage tanks, whether new or existing, with the fill point not located within a diked area shall be provided with a catch basin or similar containment, except for tanks exempted by par. (d) and tanks that are exempted from secondary containment by s. ATCP 93.420 (1) (a) to (c).

(b) The catch basin or similar containment to contain spillage at the fill point shall have a minimum liquid capacity of 5 gallons, except where the catch basin or similar containment was installed before February 1, 2009.

(c) The basin shall be equipped with a method to remove product or a drain system that directs spilled product into the tank.

(d) The following tanks are exempt from par. (a):

1. Tanks provided with controls before February 1, 2009, that comply with this subsection.

2. Tanks filled with a manual-shutoff nozzle without a latch-open device.

Note: The “controls” referred to in this subdivision may be something other than a mechanical device. In other words, they are anything that will reliably prevent a loss of product at the fill point from reaching the environment.

3. Tanks filled with a tight-connect with either a dry break connection or a manual shutoff valve on the hose-end connection.

(7) Aboveground tanks that are filled via handheld nozzles shall be constantly attended during product delivery and shall be provided with overfill prevention equipment which notifies the person filling the tank, with either an audible or a visual signal that the liquid level has reached 90 percent of the tank’s capacity.

(8) Tanks located remote from the fill point, that are filled only with a manual shutoff nozzle without a latching mechanism shall be provided with overfill prevention equipment which notifies the person filling the tank, with both an audible and a visual signal, that the liquid level has reached 90 percent of the tank’s capacity.

(9)

(a) Any of the following new aboveground double-wall tanks storing Class IIIB products shall be provided with overfill prevention equipment which notifies the person filling the tank, with both an audible and a visual signal, that the liquid level has reached 90 percent of the tank’s capacity:

1. Tanks using tight-connect delivery.

2. Tanks located remote from the fill point.

(b) Any of the following existing aboveground double-wall tanks storing Class IIIB products shall be provided with overfill prevention equipment which notifies the person filling the tank, with both an audible and a visual signal, that the liquid level has reached 90 percent of the tank’s capacity:

1. Tanks using tight-connect delivery.

2. Tanks located remote from the fill point that use delivery nozzles with latch-open devices.

(10)

(a) Any of the following double-wall aboveground tanks that are installed on or after November 1, 2019, shall be provided with overfill prevention equipment which notifies the person filling the tank, with both an audible and a visual signal, that the liquid level has reached 90 percent of the tank’s capacity, and which automatically shuts off flow when the quantity of liquid in the tank reaches 95 percent of the tank’s capacity, except this requirement does not apply to the tanks addressed in sub. (9) (a):

1. Tanks using tight-connect delivery.

2. Tanks located remote from the fill point that use delivery nozzles with latch-open devices.

(b) Any of the following existing aboveground double-wall tanks shall be provided with overfill prevention equipment which notifies the person filling the tank, with both an audible and a visual signal, that the liquid level has reached 90 percent of the tank’s capacity, and which automatically shuts off flow when the quantity of liquid in the tank reaches 95 percent of the tank’s capacity, except this requirement does not apply to the tanks addressed in sub. (9) (b):

1. Tanks using tight-connect delivery.

2. Tanks located remote from the fill point that use delivery nozzles with latch-open devices.

(11) Any single-wall aboveground tank which is not addressed in subch. III and which either is existing by November 1, 2019, or is installed on or after that date shall be provided with overfill prevention equipment which notifies the person filling the tank, with both an audible and a visual signal, that the liquid level has reached 90 percent of the tank’s capacity.

(12) Overfill prevention equipment shall be tested before it is placed into service to ensure it is set to activate at the levels specified in this section and that it will activate when the contained liquid reaches those levels. This testing shall be performed in accordance with one of the following:

(a) Requirements developed by the manufacturer, if the manufacturer has developed testing requirements.

(b) An approved standard developed by a nationally recognized association or independent testing laboratory.

(c) Requirements determined by the department to be no less protective of human health and the environment than the requirements listed in this subsection.

(13)

(a) Operators shall utilize the procedures and equipment as specified in PEI RP600 for preventing overfilling of new and existing shop-built aboveground tanks.

(b) Fuel-delivery persons shall utilize the procedures in PEI RP600 for preventing overfilling of new and existing shop-built aboveground tanks, and may not interfere with equipment that is intended to prevent overfilling.

Note: PEI RP600 does not mandate installation of equipment, but instead addresses how to effectively use the equipment that is provided, as required by other sections and referenced standards in this chapter.

Note: Under ss. ATCP 93.470 and ATCP 93.585 (2) (b), fuel-delivery persons must immediately inform the owner or operator of any spilling or overfilling which occurs during the delivery procedure and which may result in or be a release. Requirements for the owner or operator to report, investigate, and clean up any spills and overfills are contained in ss. ATCP 93.575 to 93.585.

Note: Overfill-prevention requirements for bulk plant tanks are in PEI RP800, and corresponding requirements for hazardous liquid tanks containing substances that are not flammable or combustible are in s. ATCP 93.350.

Note: API RP 1007, Loading and Unloading of MC 306/DOT 406 Cargo Tank Motor Vehicles, is a guideline for use by truck drivers and other personnel that includes specific steps for unloading tank trucks into aboveground and underground tanks in a safe and efficient manner which protects the environment. It is available at http://publications.api.org.

History: CR 17-092: cr. Register October 2019 No. 766, eff. 11-1-19; correction in (6) (a) made under s. 35.17, Stats., and correction in (10) (a), (11) made under s. 13.92 (4) (b) 14., Stats., Register October 2019.

ATCP 93.420 Secondary containment.

(1) Application. Aboveground storage tanks using secondary containment as a method of spill control shall comply with the secondary containment requirements in NFPA 30 section 22.11 and this section, except this requirement does not apply to any of the following tanks:

(a) Tanks covered in ss. ATCP 93.610 (1) to (3) and 93.630.

Note: Sections ATCP 93.610 (1) to (3) and 93.630 cover tank wagons, movable tanks, tank vehicles, and aboveground farm tanks.

(b) Tanks storing Class IIIB liquids other than used oil.

Note: Federal regulations, such as the Spill Prevention Control and Countermeasure requirements in 40 CFR part 112, may also apply to these tanks and be more restrictive but are not enforced by the department.

(c) Tanks storing Class IIIB liquids that are not in the same diked area as a tank containing Class I, II, or IIIA liquids.

(2) Dike systems for tanks.

(a) Weather exposure. Where a dike system is used to provide secondary containment for a tank system that is exposed to the weather, the dike system shall be constructed in accordance with NFPA 30 section 22.11; ACI 350.2R, if concrete is used; and this subsection.

(b) Capacity. The capacity of a dike system open to the weather shall be 25 percent larger than required under NFPA 30 section 22.11.1.2 or 22.11.2.2.

(c) Construction. The walls and floor of the dike system shall be constructed of earth, solid masonry, steel, precast concrete, engineered poured concrete, or other materials approved by the department.

(d) Sealing. Dike systems with the walls and floor made of steel or poured or precast concrete shall have all cracks, seams, and joints sealed to be liquid-tight.

(e) New earthen or masonry dikes.

1. New dike systems that have walls or floor made of earth or masonry shall be lined with a synthetic material having a permeability of no faster than 10-6 centimeters per second for the substance stored, except as provided in subd. 2.

a. Tanks included in either subd. 2. b. or c. may have dike systems designed by an engineer, with the walls and floor made of clay material having a permeability of no faster than 10-6 centimeters per second for the substance stored. The dike system shall be designed to maintain the permeability for a minimum of 35 years.

b. Tanks that have a double bottom which includes interstitial monitoring.

c. Single-bottom tanks that are constructed to ensure that any leaks from the bottom will drain to a conspicuous location and be contained there.

3. All piping shall be routed over the top of the dike wall.

Note: A method to achieve compliance with subd. 2. c. could include placing a tank over coarse aggregate that rests on a concrete base which is configured to provide the specified drainage and containment.

Note: As applied under s. ATCP 93.440 (2) and (3), API 653 requires routine inspection of field-erected tanks, and STI SP001 requires periodic inspection of shop-built tanks for evidence of leaks.

(f) Existing earthen or masonry dikes.

1. Tanks may be installed within an existing dike system that has walls or floor made of earth or masonry only if all of the following conditions are met:

a. The dike system complies with par. (b).

b. The new tanks comply with par. (e) 2. b. or c.

c. All other tanks within the dike system have overfill protection as specified in NFPA 30 section 21.7.1.

2. An existing dike system that has walls or floor made of earth or masonry may be expanded with materials which are similar to the materials in the existing walls and floor. After that expansion, tanks may be installed within the dike system only if all of the conditions in subd. 1. a. to c. are met.

3. Tanks within an existing dike system that has walls or floor made of earth or masonry may be converted from storing an unregulated substance to storing a regulated substance only if all of the following conditions are met:

a. The dike system complies with par. (b).

b. The converted tanks comply with par. (e) 2. b. or c.

c. All other tanks within the dike system have overfill protection as specified in NFPA 30 section 21.7.1.

4. All new or replacement piping shall be routed over the top of the dike wall.

(g) Approval and installation of synthetic liners. Synthetic liners shall be approved in accordance with s. ATCP 93.130 and installed under the direct supervision of a qualified representative of the manufacturer

(h) Testing and maintenance. All new and existing synthetic liners and their seams shall be tested and maintained in accordance with the manufacturer’s recommendations.

(i) Inspection of seams. Dike systems shall be constructed and maintained such that the liquid-tight seams can be visually inspected, except as provided in pars. (j) and (k).

(j) Seam exceptions. The following dike systems are not required to have seams that can be visually inspected:

1. Concrete or steel systems that are coated with a liquid-proof sprayed coating.

2. Systems using an additional synthetic liner.

3. Systems using a synthetic liner that is covered with earthen material.

(k) Existing seams. For existing dike systems, the seams directly under the tank are not required to be visible for inspection.