Subpart
1.
General requirements.
Liquid bulk pesticide storage containers must be confined to
a secondary containment area that is adequate, in the event of a release, to
prevent the movement of liquid pesticides to surface or ground water. The
loading area as specified in part
1505.3070 must not be located,
designed, or constructed in such a way so as to compromise the required
secondary containment of subpart
2. The secondary containment
provisions also apply to liquid bulk pesticides stored in a location covered by
a roof. A secondary containment area must consist of:
A. a wall and liner as provided under
subparts
4
and
5;
B. a prefabricated secondary containment
basin as provided under subpart
6; or
C. other safeguards approved by the
commissioner.
Subp. 2.
Capacity.
The capacity of a secondary containment area for a bulk
pesticide storage facility must be at least equal to the sum of all of the
following:
A. the greatest volume of
liquid bulk pesticide or liquid bulk fertilizer that could be released from the
largest storage container within the secondary containment area;
B. 25 percent of the capacity of the largest
liquid bulk pesticide or liquid bulk fertilizer storage container located
within the secondary containment area for an outdoor storage container, or ten
percent of the capacity of the largest liquid bulk pesticide container or
liquid bulk fertilizer if stored in a location covered by a roof; and
C. the total volume of released liquid which
would be displaced by the portions of all other storage containers within the
secondary containment area to the height of the containment wall and all other
fixtures and materials located within the secondary containment area (including
pesticide or fertilizer diluent, empty pesticide containers, recovered
pesticide or fertilizer releases, and liquid pesticide or fertilizer metering
equipment).
Subp. 3.
Storage with other commodities or equipment.
A. Liquid bulk pesticide, liquid bulk
fertilizer, pesticide or fertilizer diluent, empty pesticide containers,
recovered pesticide or fertilizer releases, or liquid pesticide or fertilizer
metering equipment may be stored within the bulk pesticide secondary
containment area.
B. The total
containment capacity calculated in subpart
2 may not be compromised by
storing liquid bulk pesticide or liquid bulk fertilizer, pesticide or
fertilizer diluent, pesticide containers, pesticide or fertilizer releases,
pesticide or fertilizer metering equipment, or other equipment or products in
amounts greater than the amounts which were originally calculated as necessary
displacement in subpart
2.
C. A liquid bulk pesticide storage
containment area may be located within the boundary of a liquid bulk fertilizer
containment area if:
(1) the containment areas
are separated by a wall described in subpart
4;
(2) the bulk pesticide is contained in an
anchored prefabricated containment unit as described in subpart
6; or
(3) each bulk pesticide storage container and
its appurtenances is effectively protected from corrosion and flotation by
liquid bulk fertilizers.
Subp. 4.
Walls.
The walls of a secondary containment area must be made of
ferrous metal, inorganic soil, stainless steel, reinforced concrete, or solid
reinforced masonry and must be designed to withstand a full hydrostatic head of
any released liquid. Cracks and seams must be sealed as needed to prevent
leakage. Walls constructed of inorganic soil must be lined as provided under
subpart
5, item D, be protected from
erosion, and have a horizontal to vertical slope of at least three to one,
unless a steeper slope is consistent with good engineering practice. Walls may
not exceed six feet in height above the interior grade.
A. All bulk pesticide tanks must be placed a
minimum of one foot from a secondary containment area wall.
B. Tanks over ten feet high stored outdoors
must be located at least three feet from the secondary containment area
wall.
C. The walls of a secondary
containment area may not contain a drain or other similar opening.
D. Masonry walls must be reinforced, capped
with concrete, and parged on the interior.
E. The joint between a masonry wall and any
floor or subsurface that it is constructed on must be constructed, sealed, and
protected in such a way that it prevents any pesticide leakage from leaving the
containment area.
Subp.
5.
Lining.
A. The
base of a secondary containment area and any inorganic soil walls of a
secondary containment area must be lined with reinforced concrete, a synthetic
liner, an inorganic soil liner, ferrous metal, or stainless steel designed to
limit the permeability of the base and walls. Liners must meet the requirements
of this subpart. The base of a secondary containment area may not contain a
drain or other similar opening used to release pesticides or precipitation.
Dissimilar materials may not be used together for a wall and liner combination
unless approved by the commissioner.
B. Concrete liners must be designed according
to good engineering practices to withstand any foreseeable loading conditions,
including a full hydrostatic head of released liquid. Cracks and seams must be
sealed to prevent leakage.
C.
Synthetic liners must have a minimum thickness of 30 mils (0.8 millimeters), be
chemically compatible with the materials being stored within the secondary
containment area, be photo-resistant, and be puncture resistant. Confirmation
of chemical compatibility and an estimate of liner life must be retained by the
firm for inspection upon request by the Department of Agriculture. The
synthetic liner must be protected by a 12-inch (30-centimeter) layer of
inorganic soil or half-inch diameter rounded stone above the liner and a
six-inch (15-centimeter) layer of inorganic soil below the liner. Soil layers
must be free of large rocks, angular stones, sticks, or other materials that
may puncture the liner. Synthetic liners must be installed according to the
manufacturer's recommendations and, if necessary, under the supervision of a
qualified representative of the manufacturer, and all field-constructed seams
must be tested, and repaired if necessary, in accordance with the
manufacturer's recommendations. Pesticide releases onto the inorganic soil
portion of a synthetic liner containment area must be managed by the removal of
contaminated soils. Disposition of contaminated soils is subject to approval
from the Department of Agriculture. Integrity of the inorganic soil portion of
the synthetic liner containment area must be restored under all
circumstances.
D. Soil liners must
comply with subitems (1) to (5).
(1) A liner
may be constructed of inorganic soil treated with bentonite clay if the liner
meets the requirements of this subitem. The liner must be designed and
constructed according to good engineering practices, extend a minimum of six
feet beyond the wall, and achieve a coefficient of permeability not to exceed 1
X 10-6 cm/sec, with a thickness of not less than six inches (15 centimeters).
The liner must be covered by an inorganic soil layer not less than six inches
(15 centimeters) thick. Liners may not be constructed of frost-susceptible
soils, which include silts and silty sand.
(2) Bentonite-treated liners must consist of
a uniform mixture of inorganic soil and bentonite. The inorganic soil used in
the mixture must have a plasticity index of at least 12. At least 30 percent by
weight of the inorganic soil must pass a No. 200 sieve, and less than five
percent of the inorganic soil must be retained on a No. 4 sieve. Ninety percent
of the bentonite by weight must pass a No. 80 sieve, and the inorganic
soil-bentonite mixture must contain at least five percent bentonite by
weight.
(3) An inorganic soil may
not be used as part of a soil liner if less than 50 percent by weight of the
soil passes a No. 200 sieve, or if more than five percent by weight of the
inorganic soil is retained on a No. 4 sieve.
(4) Soil liners must be maintained to prevent
cracking or other conditions that may compromise the integrity of containment.
Pesticide releases into an inorganic soil-bentonite liner containment area must
be managed by removal of contaminated soils within 48 hours. Contaminated soils
must be used at labeled rates consistent with labeled end uses for the intended
crop, or stored and used later at labeled rates consistent with labeled end
uses for the intended crop, or disposed of according to local, state, and
federal regulations. Integrity of the inorganic soil walls and inorganic
soil-bentonite liner after a spill must be restored under all
circumstances.
(5) An owner or
manager shall submit to the commissioner, upon request, certification by a
registered engineer practicing in the geotechnical field to verify that the
coefficient of permeability of the liner does not exceed 1 X 10-6 cm/sec or
that the inorganic soil lined containment area will contain released liquid to
the height of the containment wall for at least 72 hours.
Subp. 6.
Prefabricated
secondary containment basin.
A prefabricated secondary containment basin must be composed
of a rigid prefabricated basin having both a base and walls constructed of
steel or synthetic materials which are resistant to corrosion, puncture, or
cracking. Materials used for the prefabricated basin must be chemically
compatible with the products being stored in the bulk pesticide tank. A written
confirmation of compatibility from the basin manufacturer must be kept on file
at the storage facility or at the nearest local office from which the storage
facility is administered. The prefabricated facility must be designed and
installed to contain the amounts listed in subpart
2, including the tank load
and a full hydrostatic head of any released liquid. Multiple basins connected
to provide the capacity required under subpart
2, must be connected in a way
that assures an unrestricted transfer of released liquid between basins. A
prefabricated containment basin may not be located where fire could damage the
containment vessel and compromise the intended containment.
