| (A) For piping systems in which regulated substances
are conveyed under pressure to an aboveground dispensing unit, a UL-listed
(or agency accepted equivalent listing by ULC) emergency shut-off
valve (also called a shear or impact valve) shall be installed in
each pressurized delivery or product line and shall be securely anchored
at the base of the dispenser. This shut-off valve shall include a
fusible link, and shall be designed to provide a positive shut-off
of product flow in the event that a fire, collision, or other emergency
occurs at the dispenser end of the pressurized line.
(B) UL-listed (or agency accepted equivalent listing
by ULC, or Factory Mutual Research Corporation (FMRC)) flexible connectors
shall be installed at both ends of each pressurized product or delivery
line to provide flexibility and to allow for vertical and horizontal
movement in the piping, unless inherently flexible piping is installed
in accordance with manufacturer's requirements and in accordance with
an applicable code or standard of practice developed by a nationally
recognized association or independent testing laboratory. The use
of metal swing joints in a pressurized UST piping system is specifically
prohibited.
(C) If buried and in contact with soil or backfill
materials, all metallic pipe, valves, and fittings (including flexible
connectors) shall be equipped with corrosion protection meeting the
applicable requirements in §334.49 of this title.
(D) Only UL-listed (or agency accepted equivalent listing
by ULC, or FMRC) flexible connectors or nonmetallic piping listed
for aboveground use or listed for use in sumps can be used without
backfill cover in sumps, manways, or dispenser pans.
(d) Secondary containment for UST systems.
(1) Applicability.
(A) A secondary containment system meeting the requirements
of this subsection shall be installed as part of any hazardous substance
UST system.
(B) A double-wall tank and piping system (or approved
alternative) meeting the applicable requirements of this subchapter
shall be installed for any UST system situated on the Edwards Aquifer
recharge or transition zones or contributing zone within the transition
zone, in accordance with Chapter 213 of this title (relating to Edwards
Aquifer).
(C) A UST system, at a minimum, shall incorporate secondary
containment as specified in Texas Water Code, §26.3476, if the
UST system is located in an area described in that provision.
(D) The agency may specifically require the installation
of a secondary containment system meeting the requirements of this
subsection at other times when necessary for the protection of human
health or safety or the environment.
(E) Requirements applicable to new tanks, piping and/or
dispensers (including related sumps or manways) installed on or after
January 1, 2009:
(i) Any new tank or piping installed as part of a UST
system must incorporate secondary containment in accordance with the
applicable requirements of this subchapter, except that external liners
will not be allowed as a secondary containment method.
(ii) Up to 35% of the total original length of an existing
single-wall piping can be replaced with new single-wall piping in
accordance with the applicable requirements of this subchapter without
triggering the secondary containment requirement for that piping,
unless the new piping segment connects the existing piping to a new
dispenser. If more than 35% of the total original length of an existing
single-wall piping is to be replaced, or the new piping segment connects
the existing piping to a new dispenser, that piping segment must be
replaced with a piping which incorporates secondary containment.
(iii) The interstice of the secondarily contained tank
and/or piping must be monitored in accordance with the requirements
of §334.50(d)(7) of this title.
(iv) Any sumps (including dispenser sumps) or manways
which are used for interstitial monitoring of piping must be compatible
with the stored substance(s), must be installed and maintained in
a manner that assures that their sides, bottoms, and any penetration
points are liquid tight, and must be inspected in accordance with
the requirements in §334.42 and §334.48 of this title (relating
to General Standards; and General Operating and Management Requirements).
(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
Cont'd... |
