| (v) Under-dispenser containment in the form of a dispenser
sump is required for any new dispenser. A new dispenser is defined
in §334.2 of this title (relating to Definitions). New dispensers
must employ a dispenser sump which is compatible with the stored substance;
is installed and maintained in a manner that assures that its sides,
bottoms, and any penetration points are liquid tight; and must be
inspected for tightness annually and tested for tightness, immediately
after installation and at least once every three years thereafter.
(vi) Any sumps (including dispenser sumps) or manways
which are used for interstitial monitoring of piping must be equipped
with a liquid sensing probe(s) which will alert the UST system owner
or operator if more than two inches of liquid collects in any sump
or manway.
(vii) Liquids and/or debris found in any sumps (including
dispenser sumps) or manways which are used for interstitial monitoring
of piping must be removed within 96 hours of alert or discovery and
properly disposed.
(viii) Inspections and testing.
(I) Inspections must be performed by a qualified person
who is competent to conduct the inspection in accordance with recognized
industry practices and in accordance with industry standards, if applicable.
(II) Testing of tanks and/or piping shall be performed
in accordance with the applicable requirements of this chapter. Testing
of sumps (including dispenser sumps) or manways must be performed
by a qualified person who is competent to conduct the inspection in
accordance with recognized industry practices and in accordance with
industry standards, if applicable.
(2) General performance standards. All secondary containment
systems installed as part of a UST system shall be:
(A) designed, installed, and operated in a manner that
will prevent the release of regulated substances from such secondary
containment system into the surrounding soil, backfill, groundwater,
or surface water during the operational life of the UST system;
(B) capable of collecting and containing releases of
regulated substances from any portion of the primary containment vessels
(e.g., tanks and piping) until such released substances are removed;
(C) constructed of or lined with materials which are
compatible with the stored regulated substance;
(D) constructed of materials having sufficient strength
and thickness to prevent failure due to pressure gradients (including
static head and external hydrological forces), physical contact with
the stored regulated substance (and any other substance to which they
may normally be exposed), climatic conditions, the stresses of installation,
and the stresses of daily operation (including stresses from nearby
vehicular traffic); and
(E) installed on a properly designed and properly placed
bedding or backfill material which is capable of providing adequate
support for the secondary containment system, capable of providing
adequate resistance to any pressure gradients above and below the
system, and capable of preventing failure due to settlement, compression,
or uplift.
(3) Secondary containment for tanks. One or more of
the following methods may be used to provide secondary containment
for tanks.
(A) Double-wall tanks. Double-wall tanks may be used
to comply with the secondary containment requirements of this subchapter,
provided that such tanks shall meet the following additional provisions.
(i) The secondary wall of such double-wall tanks shall
be structurally designed to contain and support the full-load capacity
of the primary tank without failure.
(ii) The double-wall tank (including both the primary
and secondary tank walls) shall be protected from corrosion in accordance
with one or more of the allowable methods included in §334.49
of this title.
(iii) The double-wall tank shall be designed, installed,
operated, and maintained in accordance with one of the applicable
codes or standards of practice listed as follows:
(I) for fiberglass-reinforced plastic tanks: UL Standard
1316, " Glass-Fiber-Reinforced Plastic Underground Storage Tanks
for Petroleum Products, Alcohols, and Alcohol-Gasoline Mixtures; "
(II) for steel tanks: STI Standard F841, "Standard
for Dual Wall Underground Steel Storage Tanks; " UL Standard
58, "Standard for Steel Underground Tanks for Flammable and Combustible
Liquids; " and other applicable UL standards for double-wall
steel tanks; and
(III) any other code or standard of practice developed
by a nationally recognized association or independent testing laboratory
that has been reviewed and determined by the agency to be no less
protective of human health and safety and the environment than the
standards described in subclauses (I) and (II) of this clause, in
accordance with procedures in §334.43 of this title.
(iv) The double-wall tank system shall be installed
in accordance with the requirements in §334.46(f)(2) of this
title.
(B) External liners. Tank excavation liners may be
used to comply with the secondary containment requirements of this
paragraph, provided that such liners shall meet the following additional
provisions.
(i) The tank excavation liner shall consist of an artificially
constructed material that is of sufficient strength, thickness, puncture-resistance,
and impermeability (i.e., allow permeation at a rate of no more than
0.25 ounces per square foot per 24 hours for the stored regulated
substance) in order to permit the collection and containment of any
releases from the UST system. The criteria for evaluation of the liner
for compliance with this clause shall be in accordance with accepted
industry practices for materials testing. Types of liners which may
be used include certain reinforced and unreinforced flexible-membrane
liners, rigid fiberglass-reinforced plastic liners, and reinforced
concrete vaults.
(ii) The liner shall be protected from corrosion in
accordance with one or more of the allowable methods included in §334.49
of this title.
(iii) The liner shall be sufficiently compatible with
the stored regulated substance, so that any regulated substance collected
in the liner system shall not cause any substantial deterioration
of the liner that would allow the regulated substances to be released
into the environment.
(iv) The liner shall be designed to provide a containment
volume of no less than 100% of the full capacity of the largest tank
within its containment area.
(v) The liner shall be installed in accordance with
the requirements in §334.46(f)(4) of this title.
(4) Secondary containment for piping. One or more of
the following methods shall be used to provide secondary containment
for piping.
(A) Double-wall piping. Double-wall piping systems
may be used to comply with the secondary containment requirements
of this subchapter, provided that such piping systems meet the following
additional provisions.
(i) The double-wall piping system shall be designed
to contain a release from any portion of the primary piping within
the secondary piping walls.
(ii) The double-wall piping system (including both
the primary and secondary piping) shall be protected from corrosion
in accordance with one or more of the allowable methods included in §334.49
of this title.
(iii) The double-wall piping system shall be designed,
installed, and operated in accordance with a code or standard of practice
developed by a nationally recognized association or independent testing
laboratory.
(iv) The double-wall piping system shall be installed
in accordance with the requirements in §334.46(f)(3) of this
title.
(B) External liners. External piping trench liners
may be used to comply with the secondary containment requirements
of this paragraph, provided that such liners meet the additional provisions
in paragraph (3)(B) of this subsection.
(e) Technical standards for other new UST system equipment.
(1) Vent lines. All underground portions of the vent
lines (including all associated underground valves, fittings, and
connectors) shall be designed and constructed in accordance with the
piping requirements in subsection (c)(1) of this section, shall be
properly protected from corrosion in accordance with one of the allowable
methods in §334.49 of this title, and shall be installed in accordance
with a code or standard of practice developed by a nationally recognized
association or independent testing laboratory.
(2) Fill pipes. All fill pipes (including any connected
fittings) shall be:
(A) designed and constructed in accordance with the
piping requirements in subsection (c)(1) of this section;
(B) properly protected from corrosion in accordance
with one of the allowable methods in §334.49 of this title;
Cont'd... |
