(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.
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.
(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.
(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.
(n)
Dike maintenance. Dikes shall be maintained in accordance with
API 2610 and s.
ATCP 93.400(8)
(e).
(3) SECONDARY CONTAINMENT TANKS.
(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.
(b) Secondary containment tanks shall be
provided with an approved method of interstitial leak detection.
(c) For electronic interstitial monitoring,
the sensor shall be of a normally-closed type.
(d) Interstitial leak detection devices shall
be tested for operability and functionality at installation.
(4) PIPING. All underground piping
connected to an aboveground tank shall comply with the secondary containment
requirements in s.
ATCP 93.400(3).
(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.
Note: This transfer requirement does not apply
to transfers of used oil or fuel oil for heating or other burning
purposes.
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.
