Current through Register Vol. 48, No. 9, September 27, 2024
(a) Secondary containment systems must be:
(1) Designed, installed, and operated to
prevent any migration of materials or accumulated liquid out of the system to
the soil, ground water, or surface water at any time during the use of the tank
system; and
(2) Capable of
detecting and collecting releases and accumulated liquids until the collected
material is removed.
Note to paragraph (a): If the collected material is a
hazardous waste under R.61-79.261, it is subject to management as a hazardous
waste in accordance with all applicable requirements of R.61-79.262 through
265, 266, and 268. If the collected material is discharged through a point
source to waters of the United States, it is subject to the requirements of
sections 301, 304, and 402 of the Clean Water Act, as amended. If discharged to
a Publicly Owned Treatment Works (POTW), it is subject to the requirements of
section 307 of the Clean Water Act, as amended. If the collected material is
released to the environment, it may be subject to the reporting requirements of
40 CFR part 302.
(b) To meet the requirements of paragraph (a)
of this section, secondary containment systems must be at a minimum:
(1) Constructed of or lined with materials
that are compatible with the materials(s) to be placed in the tank system and
must have sufficient strength and thickness to prevent failure owing to
pressure gradients (including static head and external hydrological forces),
physical contact with the material to which it is exposed, climatic conditions,
and the stress of daily operation (including stresses from nearby vehicular
traffic);
(2) Placed on a
foundation or base capable of providing support to the secondary containment
system, resistance to pressure gradients above and below the system, and
capable of preventing failure due to settlement, compression, or
uplift;
(3) Provided with a
leak-detection system that is designed and operated so that it will detect the
failure of either the primary or secondary containment structure or the
presence of any release of hazardous secondary material or accumulated liquid
in the secondary containment system at the earliest practicable time;
and
(4) Sloped or otherwise
designed or operated to drain and remove liquids resulting from leaks, spills,
or precipitation. Spilled or leaked material and accumulated precipitation must
be removed from the secondary containment system within twenty-four (24) hours,
or in as timely a manner as is possible to prevent harm to human health and the
environment.
(c)
Secondary containment for tanks must include one (1) or more of the following
devices:
(1) A liner (external to the
tank);
(2) A vault; or
(3) A double-walled tank.
(d) In addition to the
requirements of paragraphs (a), (b), and (c) of this section, secondary
containment systems must satisfy the following requirements:
(1) External liner systems must be:
(i) Designed or operated to contain one
hundred (100) percent of the capacity of the largest tank within its
boundary;
(ii) Designed or operated
to prevent run-on or infiltration of precipitation into the secondary
containment system unless the collection system has sufficient excess capacity
to contain run-on or infiltration. Such additional capacity must be sufficient
to contain precipitation from a twenty-five-year, twenty-four-hour rainfall
event.
(iii) Free of cracks or
gaps; and
(iv) Designed and
installed to surround the tank completely and to cover all surrounding earth
likely to come into contact with the material if the material is released from
the tank(s) (i.e., capable of preventing lateral as well as vertical migration
of the material).
(2)
Vault systems must be:
(i) Designed or
operated to contain one hundred (100) percent of the capacity of the largest
tank within its boundary;
(ii)
Designed or operated to prevent run-on or infiltration of precipitation into
the secondary containment system unless the collection system has sufficient
excess capacity to contain run-on or infiltration. Such additional capacity
must be sufficient to contain precipitation from a twenty-five-year,
twenty-four-hour rainfall event;
(iii) Constructed with chemical-resistant
water stops in place at all joints (if any);
(iv) Provided with an impermeable interior
coating or lining that is compatible with the stored material and that will
prevent migration of material into the concrete;
(v) Provided with a means to protect against
the formation of and ignition of vapors within the vault, if the material being
stored or treated is ignitable or reactive; and
(vi) Provided with an exterior moisture
barrier or be otherwise designed or operated to prevent migration of moisture
into the vault if the vault is subject to hydraulic pressure.
(3) Double-walled tanks must be:
(i) Designed as an integral structure (i.e.,
an inner tank completely enveloped within an outer shell) so that any release
from the inner tank is contained by the outer shell;
(ii) Protected, if constructed of metal, from
both corrosion of the primary tank interior and of the external surface of the
outer shell; and
(iii) Provided
with a built-in continuous leak detection system capable of detecting a release
within twenty-four (24) hours, or at the earliest practicable time.
Note to paragraph (d)(3): The provisions outlined in the
Steel Tank Institute's (STI) "Standard for Dual Wall Underground Steel Storage
Tanks" may be used as guidelines for aspects of the design of underground steel
double-walled tanks.
(f) Ancillary equipment must be provided with
secondary containment (e.g., trench, jacketing, double-walled piping) that
meets the requirements of paragraphs (a) and (b) of this section except for:
(1) Aboveground piping (exclusive of flanges,
joints, valves, and other connections) that are visually inspected for leaks on
a daily basis;
(2) Welded flanges,
welded joints, and welded connections that are visually inspected for leaks on
a daily basis;
(3) Sealless or
magnetic coupling pumps and sealless valves that are visually inspected for
leaks on a daily basis; and
(4)
Pressurized aboveground piping systems with automatic shut-off devices (e.g.,
excess flow check valves, flow metering shutdown devices, loss of pressure
actuated shut-off devices) that are visually inspected for leaks on a daily
basis.
