ATCP 93.420(2)(f)2. 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.

ATCP 93.420(2)(f)3. 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:

ATCP 93.420(2)(f)3.a. a. The dike system complies with par. (b).

ATCP 93.420(2)(f)3.b. b. The converted tanks comply with par. (e) 2. b. or c.

ATCP 93.420(2)(f)3.c. c. All other tanks within the dike system have overfill protection as specified in NFPA 30 section 21.7.1.

ATCP 93.420(2)(f)4. 4. All new or replacement piping shall be routed over the top of the dike wall.

ATCP 93.420(2)(g) (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

ATCP 93.420(2)(h) (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.

ATCP 93.420(2)(i) (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).

ATCP 93.420(2)(j) (j) Seam exceptions. The following dike systems are not required to have seams that can be visually inspected:

ATCP 93.420(2)(j)1. 1. Concrete or steel systems that are coated with a liquid-proof sprayed coating.

ATCP 93.420(2)(j)2. 2. Systems using an additional synthetic liner.

ATCP 93.420(2)(j)3. 3. Systems using a synthetic liner that is covered with earthen material.

ATCP 93.420(2)(k) (k) Existing seams. For existing dike systems, the seams directly under the tank are not required to be visible for inspection.

ATCP 93.420(2)(L) (L) Separation. A separation of at least 2 feet shall be provided between any new tank and the toe of any new or existing dike wall, and a minimum of 3 inches shall be provided between the bottom of any new tank and the dike floor, to allow for visual inspection of the exterior tank surface — except this 3-inch requirement does not apply to tanks that comply with par. (e) 2. b. or c., or where otherwise approved by the department.

ATCP 93.420(2)(m) (m) Drainage. Permanent containment structures shall be designed with a manually controlled drainage system to permit the drainage of liquids resulting from leaks, spills, and precipitation, such as a manually controlled pump or siphon or a manually controlled dike valve.

ATCP 93.420(2)(n) (n) Dike maintenance. Dikes shall be maintained in accordance with API 2610 and s. ATCP 93.400 (8) (e).

ATCP 93.420(3) (3) Secondary containment tanks.

ATCP 93.420(3)(a) (a) The department may accept secondary containment tanks of any size as providing acceptable secondary containment, except where dike systems are specifically required by this chapter.

ATCP 93.420(3)(b) (b) Secondary containment tanks shall be provided with an approved method of interstitial leak detection.

ATCP 93.420(3)(c) (c) For electronic interstitial monitoring, the sensor shall be of a normally-closed type.

ATCP 93.420(3)(d) (d) Interstitial leak detection devices shall be tested for operability and functionality at installation.

ATCP 93.420(4) (4) Piping. All underground piping connected to an aboveground tank shall comply with the secondary containment requirements in s. ATCP 93.400 (3).

ATCP 93.420(5) (5) Transfer operations. In order to prevent a spill from moving beyond the loading or unloading area, any tank which has a capacity of 5,000 gallons or more and which is involved in transfer operations for bulk loading and unloading of tank cars or tank vehicles at facilities that refine, process, distribute, or manufacture liquids regulated under this code shall be provided with a catchment basin or treatment facility to contain the maximum capacity of the largest compartment of a tank car or tank vehicle loaded or unloaded at the facility.

ATCP 93.420 Note Note: This transfer requirement does not apply to transfers of used oil or fuel oil for heating or other burning purposes.

ATCP 93.420 Note Note: For further information on industry practices for preventing or detecting releases with aboveground storage systems, and for protecting groundwater, surface water and soil in the event of a liquid release, see API Publication 340 — Liquid Release Prevention and Detection Measures for Aboveground Storage Facilities.

ATCP 93.420 History History: CR 17-092: cr. Register October 2019 No. 766, eff. 11-1-19.

ATCP 93.425 ATCP 93.425 Tank lining of aboveground storage tanks.

ATCP 93.425(1) (1) The installation or repair of tank linings or coatings for aboveground storage tanks shall comply with API 652 and this section.