These performance standards apply to regulated AST systems
that store stable liquids in atmospheric ASTs where internal operating
pressures do not exceed 2.5 psi. Requirements for the storage of other liquids
in other types of ASTs at greater operating pressures are found in NFPA 30
"Flammable and Combustible Liquids Code" and must be followed.
3-2-1
Design
(a) Tank Design and Materials of Construction
(1) All tanks shall be designed and built in
accordance with recognized good engineering standards for the material of
construction being used and shall be of steel or approved noncombustible
material, with the following limitations and exceptions:
(i) The material of tank construction shall
be compatible with the liquid to be stored. In case of doubt about the
properties of the liquid to be stored, the supplier, producer of the liquid, or
other competent authority shall be consulted.
(A) Tanks designed and intended for above
ground use shall not be used as underground tanks.
(B) Tanks designed and intended for
underground use shall not be used as aboveground tanks.
(ii) Tanks constructed of combustible
materials shall be subject to the approval of the Director and limited to:
(A) Use where required by the properties of
the liquid stored, or
(B) Storage
of Class IIIB liquids above ground in areas not exposed to spill or leak of
Class I or Class II liquid, or
(C)
Storage of Class IIIB liquids inside a building protected by an approved
automatic fire extinguishing system.
(iii) Atmospheric tanks shall not be used for
the storage of a liquid at a temperature at or above its boiling point.
Atmospheric tanks shall be labeled and shall be built, installed, and used
within the scope of a nationally recognized construction standard; such as UL
142, Standard for Steel Aboveground Tanks for Flammable and Combustible
Liquids, or API Standard 650, Welded Steel Tanks for Oil Storage or an
equivalent standard.
(b) Vent Piping
The design, fabrication, assembly, testing, and inspection
of all piping systems for flammable and combustible liquids shall be in
conformance with the applicable sections of ANSI Standard B31, American
National Standard Code for Pressure Piping and installed in
conformance with the following requirements:
(1) Where vent pipe outlets for tanks storing
Class I liquids are adjacent to buildings or public ways, they shall be located
so that the vapors are released at a safe point outside of buildings and not
less than 12 ft (3.6 m) above the adjacent ground level. In order to aid their
dispersion, vapors shall be discharged upward or horizontally away from closely
adjacent walls. Vent outlets shall be located so that flammable vapors will not
be trapped by eaves or other obstructions and shall be at least 5 ft (1.5 m)
from building openings.
(i) Vent piping that
it is attached to or within a canopy or its supporting structure must extend a
minimum of 5 ft (1.5 m) above the highest projection of the canopy, including
the canopy fascia. When modifications to the canopy are made, this distance
must be maintained.
Exception: Where the canopy or canopy modifications
were installed before January 1, 2004, changes to existing vent piping are not
required.
(2) The
manifolding of tank vent piping shall be avoided except where required for
special purposes such as vapor recovery, vapor conservation, or air pollution
control. When tank vent piping is manifolded, pipe sizes shall be such as to
discharge, within the pressure limitations of the system, the vapors they may
be required to handle when manifolded tanks are subject to the same fire
exposure.
(3) Vent piping for tanks
storing Class I liquids shall not be manifolded with vent piping for tanks
storing Class II or Class III liquids unless means are provided to prevent the
vapors from Class I liquids from entering tanks storing Class II or Class III
liquids, to prevent possible change in classification of the less volatile
liquid.
(c) Normal
Venting
(1) Atmospheric tanks shall be
adequately vented to prevent the development of vacuum or pressure that can
distort or damage the tank or that exceeds the design pressure, as a result of
filling or emptying the tank or atmospheric temperature changes.
(2) For ASTs installed after September 30,
1994, normal vents shall be:
(i) sized in
accordance with American Petroleum Institute Standard 2000, "Venting
Atmospheric and Low-Pressure Storage Tanks", or another accepted standard; or
(ii) at least as large as the
filling or withdrawal connection, whichever is larger, but in no case less than
1 1/4 in. (3 cm) nominal inside diameter.
(3) If any AST installed after September 30,
1994 has more than one fill or withdrawal connection and simultaneous filling
or withdrawal can be made, the vent size shall be based on the maximum
anticipated simultaneous flow.
(4)
Except for tanks containing Class III liquids, vents shall be equipped with
venting devices.
(i) Tanks containing Class
IA liquids shall be equipped with venting devices that are closed, except when
venting under pressure or vacuum conditions.
(ii) Tanks containing Class IB and IC liquids
shall be equipped with venting devices that are closed, except when venting
under pressure or vacuum conditions, or with listed flame arresters.
(iii) Tanks containing Class II liquids shall
be equipped with venting devices that will protect the tank against the
intrusion of water, debris, or insects.
(5) Adequate ventilation either natural or
forced must exist to guarantee that flammable liquid vapors cannot build up to
25% of the lower flammable limit anywhere, because of the presence of the tank
facility in question.
(d) Emergency Relief Venting
(1) Every AST shall have some form of
construction or device that will relieve excessive internal pressure caused by
exposure to fires.
(i) This requirement shall
also apply to each compartment of a compartmented tank, the interstitial space
of secondary containment-type tanks, and the enclosed space of closed-top dike
tanks, except where the tank was constructed prior to the publication of the
1996 edition of NFPA 30 "Flammable and Combustible Liquids Code".
Exception: Tanks larger than 12,000 gallons
capacity storing Class IIIB liquids do not require emergency relief venting
unless they are within the diked area or the drainage path of Class I or Class
II liquids.
(2) In a vertical tank, the construction
referred to in
3-2-1(d)(1) may
take the form of a floating roof, lifter roof, a weak roof-to-shell seam, or
other approved pressure-relieving construction. The weak roof-to-shell seam
shall be constructed to fail preferential to any other seam. Design methods
that will provide a weak roof-to-shell seam construction are contained in API
Standard 650, Welded Steel Tanks for Oil Storage, and Standard UL 142, Standard
for Steel Aboveground Tanks for Flammable and Combustible Liquids.
(3) Where entire dependence for emergency
relief is placed upon pressure-relieving devices, the total venting capacity of
both normal and emergency vents shall be enough to prevent rupture of the shell
or bottom of the tank if vertical, or of the shell or heads if
horizontal.
(4) The total capacity
of both normal and emergency venting devices shall not be less than the
requirements of NFPA 30 "Flammable and Combustible Liquids Code".
(5) Emergency relief vent devices shall be
vapor tight and shall be permitted to be a self-closing manway cover, a manway
cover provided with long bolts that permit the cover to lift under internal
pressure, or additional or larger relief valve or valves.
(6) Each commercial tank venting device shall
be stamped with the operational pressures and capacities required by NFPA 30
"Flammable and Combustible Liquids Code".
(7) For the extension of emergency vent
piping, piping to or from approved emergency vent devices shall be sized to
provide emergency vent flows that limit the back pressure to less than the
maximum pressure permitted by the design of the tank.
(8) The required emergency relief venting
capacities for tanks and devices, requirements for tanks storing unstable
liquids, additional requirements for tanks other than atmospheric and other
requirements for emergency relief venting design are found in NFPA 30
"Flammable and Combustible Liquids Code".
(e) Tank Openings Other than Vents
(1) Each connection to an AST through which
liquid can normally flow shall be provided with an internal or an external
valve located as close as practical to the shell of the tank.
(2) Each connection below the liquid level
through which liquid does not normally flow shall be provided with a
liquid-tight closure. This may be a valve, plug, or blind, or a combination of
these.
(3) Openings for gauging on
tanks storing Class I liquids shall be provided with a vapor-tight cap or
cover. Such covers shall be closed when not gauging.
(4) Fill pipes that enter the top of a tank
shall terminate within 6 in (15 cm) of the bottom of the tank. Fill pipes shall
be installed or arranged so that vibration is minimized.
Exception: Fill pipes in tanks whose vapor space,
under normal operating conditions, is not in the flammable range need not meet
this requirement.
(5) Filling and emptying connections for
Class I, Class II, and Class IIIA liquids that are made and broken shall be
located outside of buildings at a location free from any source of ignition and
not less than 5 ft. (1.5 m) away from any building opening. Such connections
for any liquid shall be closed and liquid tight when not in use and shall be
properly identified.
(f)
Static Protection for all ASTs
(1) Grounding
Required
All equipment such as tanks, machinery and piping, where an
ignitable mixture may be present shall be bonded or connected to a
ground.
(2) Bonding
Facilities Required
The bond or ground or both shall be physically applied or
shall be inherently present by the nature of the installation; and
(i) Bonding facilities for protection against
static sparks during the loading of tank vehicles through open domes shall be
provided:
(A) Where Class I liquids are
loaded, or
(B) Where Class II or
Class III liquids are loaded into vehicles that may contain vapors from
previous cargoes of Class I liquids; and
(ii) Bonding facilities shall consist of a
metallic bond wire permanently electrically connected to the fill stem, or to
some part of the rack structure in electrical contact with the fill stem. The
free end of such wire shall be provided with a clamp or equivalent device for
convenient attachment to some metallic part in electrical contact with the
cargo tank of the tank vehicle. (This can be a simple ground clamp used while
loading).
(g)
Standards for Piping, Valves, and Fittings
(1)
General and Suction Systems.
(i) For the
purpose these regulations, piping connected to an AST is considered to be
suction piping when the entire length of piping is at a higher elevation than
the AST it is connected to, and where there is no pump installed between the
tank and piping. All other piping connected to an AST is pressurized piping.
(A) ASTs with underground piping must meet
all of the requirements for underground pressurized piping
contained in Article 2 of these regulations, including the construction,
corrosion protection, and installation requirements of
2-2-1(b), the
secondary containment requirements of
2-2-1(e) for
piping installed after April 14, 2011, and release detection requirements of
2-3-4 -3.
(ii) Liquid shall not be dispensed from a
tank by pressurization of the tank. Means shall be provided to prevent the
release of liquid by siphon flow.
(iii) On or after October 14, 2012, where an
AST is at an elevation that produces a gravity head on a motor fuel dispensing
device, the tank outlet shall be equipped with a device (such as a normally
closed solenoid valve) that will prevent gravity flow from the tank to the
dispenser. This device shall be located adjacent to and downstream of the main
valve specified by
3-2-1(e)(1) of
these regulations. The device shall be installed and adjusted so that liquid
cannot flow by gravity from the tank to the dispenser in the event of failure
of the piping or hose when the dispenser is not in use.
(iv) Where a suction-type dispensing system
includes a booster pump or where a suction-type dispensing system is supplied
by a tank in a manner that produces a gravity head on the dispensing device, a
listed, vacuum-actuated shutoff valve with a shear section or equivalent type
valve shall be installed directly under the dispensing device.
(A) Suction-type dispensing systems installed
before April 14, 2011 that include a solenoid valve at the tank outlet, and a
listed, rigidly anchored emergency shutoff valve incorporating a fusible link
or other thermally actuated device, designed to close automatically in event of
severe impact or fire exposure are deemed to meet this requirement.
(v) For ASTs installed after
September 30, 1994, shutoff and check valves shall be equipped with a
pressure-relieving device that will relieve the pressure generated by thermal
expansion back to the tank.
(vi)
Piping shall be routed so that exposure to physical damage is
minimized.
(vii) Piping systems
shall be supported and protected against physical damage, including damage from
stresses arising from settlement, vibration, expansion, or contraction.
(2) Remote Pumping
Systems
This section shall apply to systems for dispensing Class I
liquids and Class II liquids where such liquids are transferred from storage to
individual or multiple dispensing devices by pumps located other than at the
dispensing devices.
(i) Pumps shall be
listed and designed or equipped so that no part of the system will be subjected
to pressures above its allowable working pressure.
(ii) Each pump shall have installed, on the
discharge side, a listed leak detection device that will provide an indication
if the piping and dispensers are not essentially liquid tight. Each
leak-detecting device shall be checked and tested at least annually according
to the manufacturer's specifications.
(iii) Pumps installed above-grade and outside
of buildings shall be located not less than 10 ft. (3 m) from lines of
adjoining property that can be built upon and not less than 5 ft. (1.5 m) from
any building opening. Pumps shall be substantially anchored and protected
against physical damage.
(iv) A
listed rigidly anchored emergency shutoff valve, incorporating a fusible link
or other thermally actuated device designed to close automatically in event of
severe impact or fire exposure, shall be installed in accordance with the
manufacturer's instructions in the supply line at the base of each individual
island-type dispenser or at the inlet of each overhead dispensing device. An
emergency shutoff valve incorporating a slip-joint feature shall not be used.
The automatic closing feature of this valve shall be checked at the time of
initial installation and at least once a year thereafter by manually tripping
the hold-open linkage.
(v) Any
vapor return pipe inside the dispenser housing shall have a shear section or
flexible connector so that the liquid emergency shutoff valve will function as
described above.
(3)
Breakaway devices
A listed emergency breakaway device designed to retain
liquid on both sides of the breakaway point shall be installed on each hose
dispensing Class I and Class II liquids. Such devices are not required at
marine service stations.
(h) Compatibility Requirements
Owners/operators must use an AST system made of or lined
with materials that are compatible with the substance stored in the AST.
[Note: Owners/operators storing alcohol blends may use the
following codes to comply with the requirements of this section:
(a) American Petroleum Institute Recommended
Practice 1626, "Storing and Handling Ethanol and Gasoline-Ethanol Blends at
Distribution Terminals and Service Stations"; and
(b) American Petroleum Institute, Recommended
Practice 1627, "Storage and Handling of Gasoline-Methanol/Co-solvent Blends at
Distribution Terminals and Service Stations."]
(i) Security
(1) Where tanks are supported above the
foundations, tank supports shall be installed on firm foundations. Steel
supports or exposed piling supports for tanks storing Class I, Class II, or
Class IIIA liquids shall be protected by materials having a fire resistance
rating of not less than 2 hours.
(2) Every tank shall be supported to prevent
the excessive concentration of loads on the supporting portion of the tank
shell.
(3) The area within the
fence (if applicable) and within any dike shall be kept free of vegetation,
debris, and any other material that is not necessary to the proper operation of
the tank and piping system.
(4)
After December 22, 1996, tanks that are not listed as Standard UL 2085 Standard
for Protected Aboveground Tanks for Flammable and Combustible Liquids where
fuel is dispensed into vehicles shall be protected against vehicular collision
by suitable barriers, which may include buildings and open space which the
Director approves in writing.
(5)
Tanks which are not enclosed in vaults shall be enclosed with a chain link
fence at least 6 ft. high. The fence shall be separated from the tanks by at
least 10 ft. and shall have a gate that is secured against unauthorized entry.
This requirement applies to:
(i) Tanks at
motor fuel dispensing facilities, and
(ii) Tanks at all other facilities that have
an individual or aggregate capacity of 12,000 gallons or more.
Exception: Tanks are not required to be enclosed
with a fence if the property on which the tanks are located has a perimeter
security fence.
(6) Tanks that are unsupervised for any
period of time, or are located in isolated/remote areas, shall be secured and
shall be marked to identify the fire hazards of the tank and the tank's
contents to the general public. Where necessary to protect the tank from
tampering or trespassing, the area where the tank is located shall be
secured.
(7) For ASTs installed
after September 30, 1994, tank supports and foundations shall be designed to
minimize the possibility of uneven settling of the tank and to minimize
corrosion to any part of the tank.
3-2-2
Location and Installation
3-2-2-1
Service Stations (Motor Fuel
Dispensing Facilities and Repair Garages)
After September 30, 1994, new ASTs may only be installed at
service stations if they meet all the general requirements for ASTs, and the
service station requirements of this section. After December 22, 1996, tanks
designed and built for underground use shall not be used as ASTs. All of the
provisions in this section also apply to marine service stations and airport
service stations.
(a) For ASTs
installed after September 30, 1994, tanks storing Class I and Class II liquids
at an individual site shall be limited to a maximum individual capacity of
12,000 gallons and an aggregate capacity of 48,000 gallons unless such tanks
are installed in vaults complying with
3-2-2 -5, in which case the maximum
individual capacity shall be permitted to be 15,000 gallons.
(b) For ASTs installed after September 30,
1994, and before April 14, 2011, tanks shall be located in accordance with
Table 1 in this section, except that for secondary containment tanks, "fire
tested" tanks, "fire resistant" tanks or tanks installed in a vault, the
distance requirement from tank to dispenser is waived, provided that all tanks,
pipes and dispensers are satisfactorily protected from vehicular
traffic.
(c) For ASTs installed on
or after April 14, 2011, ASTs shall be located in accordance with Table 1
below.
|
TABLE 1
|
AST Separation at Motor Fuel
Dispensing Facilities and Repair Garages
|
|
|
Minimum Distance
(ft)
|
|
Type of Tank
|
Individual Tank Capacity
(gal)
|
From Nearest Important Building on the Same
Property
|
From Nearest Fuel Dispensing
Device
|
From Property Line That Is or Can Be Built
Upon Including Opposite Side of Public Way
|
From Nearest Side of Any Public
Way
|
Between Tanks
|
|
Tanks in vaults (measured from vault
perimeter)
|
0 - 15,000
|
0
|
0
|
0
|
0
|
Separate vault compartments for each AST
|
|
Protected ASTs (UL 2085)
|
<= 6,000 6,001 - 12,000
|
5
15
|
0
0
|
15
25
|
5
15
|
3
3
|
|
Fire-resistant ASTs (UL 2080)
|
0 - 12,000
|
25
|
25
|
50
|
25
|
3
|
|
Other ASTs meeting NFPA 30 requirements
|
0 - 12,000
|
50
|
50
|
100
|
50
|
3
|
(d) Bulk Plants with Motor Fuel Dispensing.
This section does not include facilities that meet the
requirements of
3-2-2 -3.
(1) For facilities existing before April 14,
2011:
(i) ASTs shall meet the location and
installation requirements of
3-2-2 -4.
(ii) Where the 50 ft distance requirement
from tank to dispenser is met, the following shall apply to the ASTs used for
both motor fuel dispensing
and bulk operations:
ASTs storing Class I liquids shall be limited to a maximum
individual capacity of 12,000 gallons, ASTs storing Class II liquids shall be
limited to a maximum individual capacity of 20,000 gallons, and the aggregate
capacity for all tanks shall be 80,000 gallons.
[Note: There are no individual or aggregate capacity limits
for ASTs used solely for bulk operations.]
(iii) Where the 50 ft distance requirement
from tank to dispenser is not met, the following shall apply to the ASTs used
for both motor fuel dispensing
and bulk operations:
ASTs storing Class I and Class II liquids shall be limited
to a maximum individual capacity of 12,000 gallons, and an aggregate capacity
of 48,000 gallons.
[Note: There are no individual or aggregate capacity limits
for ASTs used solely for bulk operations.]
(2) For new facilities installed
on or after April 14, 2011:
(i) ASTs used for
motor fuel dispensing shall meet the capacity and location requirements of
3-2-2 -1, except that the maximum
individual tank capacity of 12,000 gallons, indicated in Table 1, shall be
permitted to be increased to 20,000 gallons for Class II liquids, and the
aggregate capacity for all tanks shall be 80,000 gallons.
[Note: ASTs that are used for motor fuel dispensing shall
not be used for bulk operations.]
(ii) ASTs used for bulk operations shall meet
the location and installation requirements of
3-2-2 -4.
[Note: ASTs that are used for bulk operations shall not be
used for motor fuel dispensing.]
(3) ASTs used solely for bulk operations
shall not be connected by piping to ASTs or USTs used for motor fuel
dispensing, and shall not supply dispensing devices used for motor vehicle
fueling.
Exception: Where the total capacity of all ASTs
used for motor fuel dispensing and all ASTs used solely for bulk operations is
within the aggregate capacities allowed by
3-2-2 -1 (d)(1) (ii) or (iii),
changes to connected piping are not required.
(4) The motor fuel dispensing operations
shall be separated from areas in which bulk plant operations are conducted by a
fence or an approved structure (building, retaining wall, etc.), preventing
direct access from one area to the other.
3-2-2-2
Governmental, Industrial and
Commercial AST Facilities (Fleet Vehicle Motor Fuel Dispensing)
AST installations are permitted at commercial, industrial,
governmental, and manufacturing facilities where motor fuels are dispensed into
vehicles used in connection with their business by employees, but only under
one of the following conditions:
(a)
For ASTs installed before April 14, 2011, existing restricted-capacity fleet
vehicle motor fuel dispensing operations that meet the following requirements
are allowed:
(1) The facility has been
inspected and approved by the Director;
(2) No more than two (2) ASTs are in service
at the facility;
(3) No AST at the
facility has a capacity greater than 6,000 U.S. gallons;
(4) There is not more than one (1) tank at
the facility containing Class I liquids; and
(5) The spacing requirements of Table 2 below
are met.
|
TABLE 2
|
AST Separation at
Restricted-Capacity Fleet Motor Fuel Dispensing Facilities (Before April 14,
2011)
|
|
|
Minimum Distance
(ft)
|
|
Tank Capacity (gal)
|
From Nearest Important Building on the Same
Property
|
From Nearest Fuel Dispensing
Device
|
From Property Line That Is or Can Be Built
Upon, Including the Opposite Side of a Public Way
|
From Nearest Side of Any Public
Way
|
Between Tanks
|
|
660 - 750
|
5
|
0
|
10
|
5
|
3
|
|
751 - 6,000
|
5
|
0
|
15
|
5
|
3
|
(b) On or after April 14, 2011, new
restricted-capacity fleet vehicle motor fuel dispensing operations shall be
allowed where the following requirements are met:
(1) The requirements of
3-2-2 -2(a)(1) - (4) are met;
and
(2) The spacing requirements of
Table 3 below are met.
|
TABLE 3
|
AST Separation at
Restricted-Capacity Fleet Motor Fuel Dispensing Facilities (On or after April
14, 2011)
|
|
|
Minimum Distance
(ft)
|
|
Tank Capacity (gal)
|
From Nearest Important Building on the Same
Property
|
From Nearest Fuel Dispensing
Device
|
From Property Line That Is or Can Be Built
Upon, Including the Opposite Side of a Public Way
|
From Nearest Side of Any Public
Way
|
Between Tanks
|
|
660 - 2,000
|
25
|
0
|
50
|
25
|
3
|
|
2,001 - 6,000
|
25
|
0
|
75
|
35
|
3
|
(c) For ASTs installed before April 14, 2011,
if the AST system meets the requirements of
3-2-2 -1(b) it can operate under
the service station capacity allowances.
(d) On or after April 14, 2011, fleet vehicle
motor fuel dispensing operations shall be allowed where the following
requirements are met:
(1) The spacing
requirements of Table 4 below are met.
(i) The
maximum individual tank capacity of 12,000 gallons, indicated in Table 4 below,
shall be permitted to be increased to 20,000 gallons for Class II and Class III
liquids, and the aggregate capacity for all tanks shall be 80,000 gallons;
and
(ii) No minimum separation
shall be required between the dispensing device and a tank in a vault, a
protected aboveground tank, or a fire-resistant tank.
|
TABLE 4
|
AST Separation at Fleet
Motor Fuel Dispensing Facilities
|
|
|
Minimum Distance
(ft)
|
|
Type of Tank
|
Individual Tank Capacity
(gal)
|
From Nearest Important Building on the Same
Property
|
From Nearest Fuel Dispensing
Device
|
From Property Line That Is or Can Be Built
Upon Including Opposite Side of Public Way
|
From Nearest Side of Any Public
Way
|
Between Tanks
|
|
Tanks in vaults (measured from vault
perimeter)
|
0 - 15,000
|
0
|
0
|
0
|
0
|
Separate vault compartments for each AST
|
|
Protected ASTs (UL 2085)
|
<= 6,000 6,001 - 12,000
|
5 15
|
0 0
|
15 25
|
5 15
|
3 3
|
|
Fire-resistant ASTs (UL 2080)
|
0 - 12,000
|
25
|
0
|
50
|
25
|
3
|
|
Other ASTs meeting NFPA 30 requirements
|
0 - 12,000
|
50
|
50
|
100
|
50
|
3
|
3-2-2-3
Unattended Cardlock
Systems
(a) On or after April 14, 2011,
unattended cardlock systems are those motor fuel dispensing facilities already
in existence which are located at bulk plants, governmental, industrial, and
commercial facilities where only proprietary cards (or keys) issued by the
facility, and that are specific to the facility's fuel management or point of
sale system, can be used to dispense fuel. Proprietary cards do not include
cards that are available for regional or national fleet fueling.
(1) Cardlock systems installed before October
1, 1994 shall meet the AST separation distances of
3-2-2 -4(a).
(2) Cardlock systems installed on October 1,
1994 or thereafter shall meet the AST separation distances of
3-2-2 -4(a), and the
tank-to-dispenser separation distances of
3-2-2 -1(b).
(3) Persons that are issued proprietary cards
(or keys) must be knowledgeable in site-specific operating and emergency
procedures for dispensing operations.
3-2-2-4
Bulk Plants (And Other
Facilities Without Motor Fuel Dispensing)
This section applies to ASTs storing regulated substances,
including emergency generator tanks, outdoors at bulk
plants and other facilities (except those facilities covered by
3-2-2 -1) where there is no motor
fuel dispensing.
The following requirements and tables showing required
minimum separation distances apply to facilities in this section that store
stable liquids in atmospheric ASTs where internal operating pressures do not
exceed 2.5 psi. Requirements for the storage of other liquids in other types of
ASTs at greater operating pressures are found in NFPA 30 "Flammable and
Combustible Liquids Code", and must be followed.
(a) Every AST which is installed after
September 30, 1994, and used for the storage of Class I, Class II, or Class
IIIA stable liquids and operating at pressures not in excess of 2.5 psig (17.2
kPa) and designed with a weak roof-to-shell seam, or equipped with emergency
venting devices that will not permit pressures to exceed 2.5 psig (17.2 kPa),
shall be located in accordance with Table 5 in this section. Where tank spacing
is contingent on a weak roof-to-shell seam design, the user shall present
evidence certifying such construction to the Director, upon request.
Exception: Vertical tanks with weak roof-to-shell
seams that store Class IIIA liquids shall be permitted to be located at
one-half the distances specified in Table 5, provided the tanks are not within
the same diked area as, or within the drainage path of, a tank storing a Class
I or Class II liquid.
(b) Every AST which is installed after
September 30, 1994, and used for the storage of Class I, Class II, or Class
IIIA stable liquids and operating at pressures exceeding 2.5 psig (17.2 kPa) or
equipped with emergency venting that will permit pressures to exceed 2.5 psig
(17.2 kPa), shall be located in accordance with, and meet the requirements of
NFPA 30 "Flammable and Combustible Liquids Code".
(c) Every AST which is installed after
September 30, 1994, and used for the storage of liquids with boil-over
characteristics shall be located in accordance with, and meet the requirements
of NFPA 30.
(d) Every AST which is
installed after September 30, 1994, and used for the storage of unstable
liquids shall be located in accordance with, and meet the requirements of NFPA
30"Flammable and Combustible Liquids Code".
(e) For ASTs installed before April 14, 2011,
spacing (Shell-to-Shell) between any two adjacent ASTs, where one AST is
installed after September 30, 1994, with tanks storing Class I, II, or IIIA
stable liquids shall be separated in accordance with Table 5 in this
section.
(f) On or after April 14,
2011, tanks used only for storing Class IIIB liquids shall not be required to
be separated by more than 3 ft provided they are not within the same diked area
as, or within the drainage path of, a tank storing a Class I or II liquid. If
located within the same diked area as, or within the drainage path of, a tank
storing a Class I or II liquid, the tank storing Class IIIB liquid shall be
spaced in accordance with the requirements for Class IIIA liquids in Table
5.
(g) Every AST which is installed
after September 30, 1994, and used for the storage of Class IIIB stable liquids
shall be located in accordance with Table 7 in this section.
Exception: If located within the same diked area
as, or within the drainage path of, a tank storing a Class I or Class II
liquid, the tank storing Class IIIB liquid shall be located in accordance with
3-2-2 -4(a).
|
TABLE 5
|
Location of Atmospheric ASTs
Storing Stable Liquids (Class I, II, IIIA) Internal Pressure Not to Exceed a
Gauge Pressure of 2.5 psi
|
|
|
Minimum Distance
(ft)
|
|
Type of Tank
|
Protection
|
From Property Line That Is or Can Be Built
Upon, Including the Opposite Side of a Public Way
|
From Nearest Side of Any Public Way or from
Nearest Important Building on the Same Property
|
Minimum Tank Shell-to-Shell
Spacing
|
|
Floating Roof
|
Protection for exposures
|
1/2 x tank diameter
|
1/6 x tank diameter
|
Greater of
1/6 x sum of adjacent tank diameters or 3 ft
|
|
None
|
Tank diameter
|
1/6 x tank diameter
|
|
Vertical with weak roof-to-shell seam
|
Approved foam or inerting system
|
1/2 x tank diameter
|
1/6 x tank diameter
|
Greater of
1/6 x sum of adjacent tank diameters or 3 ft
|
|
Protection for exposures
|
Tank diameter
|
1/3 x tank diameter
|
|
None
|
2 x tank diameter
|
1/3 x tank diameter
|
|
Horizontal and vertical tanks with emergency
relief venting to limit pressures to 2.5 psi
|
Approved foam or inerting system
|
1/2 x value in table 6
|
1/2 x value in table 6
|
Greater of
1/6 x sum of adjacent tank diameters or 3 ft
|
|
Protection for exposures
|
Value in table 6
|
Value in table 6
|
|
None
|
2 x value in table 6
|
Value in table 6
|
|
Protected aboveground tank
|
None
|
1/2 x value in table 6
|
1/2 x value in table 6
|
Greater of
1/6 x sum of adjacent tank diameters or 3 ft
|
|
In most cases "protection for exposures" will
apply.
|
Greater of
values shown above or 5 ft
|
3 ft min. where sum of adjacent tank
diameters is <= 18 ft
|
|
PROTECTION FOR EXPOSURES - Fire
protection for structures on property adjacent to liquid storage that is
provided by (1) a public fire department or (2) a private fire brigade
maintained on the property adjacent to the liquid storage, either of which is
capable of providing cooling water streams to protect the property adjacent to
the liquid storage.
|
|
TABLE 6
|
Distances for Use with Table
5 (Above)
|
|
|
Minimum Distance
(ft)
|
|
Tank Capacity (gal)
|
From Property Line That Is or Can Be Built
Upon, Including the Opposite Side of a Public Way
|
From Nearest Side of Any Public Way or from
Nearest Important Building on the Same Property
|
|
660 - 750
|
10
|
5
|
|
751 - 12,000
|
15
|
5
|
|
12,001 - 30,000
|
20
|
5
|
|
30,001 - 39,999
|
30
|
10
|
|
TABLE 7
|
Location of ASTs Storing
Class IIIB Liquids
|
|
|
Minimum Distance
(ft)
|
|
Tank Capacity (gal)
|
From Property Line That Is or Can Be Built
Upon, Including the Opposite Side of a Public Way
|
From Nearest Side of Any Public Way or from
Nearest Important Building on the Same Property
|
|
12,000 or less
|
5
|
5
|
|
12,000 - 30,000
|
10
|
5
|
|
30,001 - 39,999
|
10
|
10
|
3-2-2-5
ASTs in Vaults
The provisions in this section apply only to ASTs installed
after September 30, 1994.
(a) There
shall be no openings in the vault enclosure except those necessary for access
to, inspection of, and filling, emptying, and venting of the tank. The walls
and floor of the vault shall be constructed of reinforced concrete at least 6
inches (15 cm) thick. The top shall be constructed of non-combustible material
constructed to be weaker than the walls. The top, floor, and tank foundation
shall be designed to withstand the anticipated loading. The vault shall be
substantially liquid tight (able to contain the product for enough time until
any release therein can be cleaned up) and there shall be no backfill material
around the tank. There shall be sufficient space between the tank and vault to
allow for inspection of the tank and its appurtenances.
(b) Each vault and its tank shall be suitably
anchored to withstand uplifting by groundwater or flooding, including when the
tank is empty.
(c) A vault shall be
designed to be wind and earthquake resistant in accordance with good
engineering practice. The vault shall be resistant to damage from the impact of
a motor vehicle, or suitable collision barriers shall be provided.
(d) Each tank shall be in its own vault.
Adjacent vaults may share a common wall.
(e) Connections shall be provided to permit
venting of each vault to dilute, disperse, and remove any vapors prior to
personnel entering the vault.
(f)
Vaults that contain tanks of Class I liquids shall be provided with continuous
ventilation at a rate of not less than 1 cubic foot per minute per square foot
of floor area (0.3m 3/min-m 3), but not less than 150 cfm (4m3/min). Failure of
the exhaust air flow shall automatically shut down the dispensing system. The
exhaust system shall be designed to provide air movement across all parts of
the vault floor. Supply and exhaust ducts shall extend to within 3 in. (7.6
cm), but not more than 12 in. (30.5 cm), of the floor. The exhaust system shall
be installed in accordance with the provisions of NFPA 91, Standard for the
Installation of Blower and Exhaust Systems for Dust, Stock, and Vapor Removal
or Conveying. Means shall be provided to automatically detect any flammable
vapors and to automatically shut down the dispensing system upon detection of
such flammable vapors in the exhaust duct at or above a concentration of 25
percent of the lower flammable limit.
(g) Each vault shall be equipped with a
detection system capable of detecting liquids, including water, and of
activating an alarm.
(h) Means
shall be provided to recover liquid from the vault. If a pump is used to meet
this requirement, the pump shall not be permanently installed in the vault.
Electric powered portable pumps shall be suitable for use in Class I, Division
1 locations, as defined in NFPA 70, "National Electrical Code".
(i) Vent pipes that are provided for normal
tank venting shall terminate at least 12 ft. (3.6m) above ground
level.
(j) Emergency vents shall be
vapor tight and shall be permitted to discharge inside the vault. Long-bolt
manhole covers shall not be permitted for this purpose.
(k) Each vault shall be provided with a means
for personnel entry. At each entry point, a warning sign indicating the need
for procedures for safe entry into confined spaces shall be posted. Each entry
point shall be secured against unauthorized entry and vandalism.
(l) Each vault shall be provided with a
suitable means to admit a fire suppression agent.
(m) The interior of any vault containing a
tank that stores a Class I liquid shall be designated a Class I, Division 1
location, as defined in NFPA 70, "National Electrical Code".
3-2-2-6
Tanks Inside
Buildings
Exception: Tanks storing Class IIIB liquids need
not comply with these provisions.
Tanks shall not be permitted inside of buildings unless the
storage of liquids in outside aboveground or underground tanks is not practical
because of government regulations, temperature considerations or production
considerations. Tanks may be permitted inside of buildings or structures only
when permitted by the Director and only under the following conditions:
(a) ASTs installed after September 30, 1994
inside buildings shall be permitted only in areas at or above grade that have
adequate drainage and are separated from other parts of the building by
construction having a fire resistance rating of at least 2 hours. Day tanks,
running tanks, and surge tanks are permitted in process areas. Class I, Class
II and Class IIIA liquids that may be heated above their flash points shall not
be stored in basements. Openings to other rooms or buildings shall be provided
with noncombustible liquid tight raised sills or ramps at least 4 in. (10 cm)
in height, or the floor in the storage area shall be at least 4 in. (10 cm)
below the surrounding floor. As a minimum, each opening shall be provided with
a listed, self-closing 1 1/2-hr (B) fire door installed in accordance with the
current versions of NFPA 80,
Standard for Fire Doors and Fire
Windows; NFPA 90A "Standard for the Installation of Air Conditioning
and Ventilating Systems", or NFPA 91, "Standard for the Installation of Blower
and Exhaust Systems for Dust, Stock, and Vapor Removal or Conveying". The room
shall be constructed without floor drains and with seals between walls and
floor of the room in order to contain the product in case of leakage or
spillage from the tank.
(1) Secondary
containment tanks do not remove the requirement for the raised sills or ramps
at openings to other rooms or buildings, or lowered floor requirements
described in (a) above. An open-grated trench across the width of the opening
inside of the room that drains to a safe location shall be permitted to be used
as an alternative to a sill or ramp.
(2) The room shall be liquid tight where the
walls join the floor and for at least 4 in. above the floor.
(3) Access aisles of at least 3 ft. width
shall be maintained for movement of firefighting personnel and fire protection
equipment.
(b) Each
connection to a tank inside buildings through which liquid can normally flow
shall be provided with an internal or an external valve located as close as
practicable to the shell of the tank; and connections for all tank openings
shall be liquid tight.
(c) Tanks
for storage of Class I or Class II liquids inside buildings shall be provided
with either:
(1) A normally closed remotely
activated valve,
(2) An
automatic-closing heat-activated valve, or
(3) Another approved device on each liquid
transfer connection below the liquid level, except for connections used for
emergency disposal, to provide for quick cutoff of flow in the event of fire in
the vicinity of the tank. This function can be incorporated in the valve
required in subsection (b) above and, if a separate valve, shall be located
adjacent to the valve required in subsection (b).
(d) Vents for tanks inside of buildings shall
be as required in
3-2-1(c),
3-2-1(d),
3-2-2 -5, except that emergency
venting by the use of weak roof seams on tanks shall not be permitted. Vents
shall terminate outside the buildings.
(1)
Section 3-2-1(c)(5)
requires that adequate ventilation exist to guarantee that flammable liquid
vapors cannot build up to 25% percent or more of the lower flammable limit,
including inside buildings.
(e) Vent piping shall be constructed and
equipped as in
3-2-1(b) and
3-2-1(c).
(f) Openings for manual gauging of Class I or
Class II liquids, if independent of the fill pipe, shall be provided with a
vapor tight cap or cover. Openings shall be kept closed when not gauging. Each
such opening for any liquid shall be protected against liquid overflow and
possible vapor release by means of a spring-loaded check valve or other
approved device. Substitutes for manual gauging include, but are not limited
to, heavy-duty flat gauge glasses, magnetic, hydraulic, or hydrostatic remote
reading devices, and sealed float gauges.
(g) The inlet of the fill pipe and the outlet
of a vapor recovery line for which connections are made and broken shall be
located outside of buildings at a location free from any source of ignition and
not less than 5 ft. (1.5 m) away from any building opening. Such connections
shall be closed and tight when not in use and shall be properly
identified.
(h) Tanks storing Class
I, Class II, and Class IIIA liquids inside buildings shall be equipped with a
device, or other means shall be provided to prevent overflow into the building.
Suitable devices include, but are not limited to, a float valve, a preset meter
on the fill line, a valve actuated by the weight of the tank contents, a low
head pump incapable of producing overflow, or a liquid tight overflow pipe at
least one pipe size larger than the fill pipe, discharging by gravity back to
the outside source of liquid or to an approved location.
(i) Tank openings provided for purposes of
vapor recovery shall be protected against possible vapor release by means of a
spring-loaded check valve or dry-break connections, or other approved device,
unless the opening is pipe-connected to a vapor processing system. Openings
designed for combined fill and vapor recovery shall also be protected against
vapor release unless connection of the liquid delivery line to the fill pipe
simultaneously connects the vapor recovery line. All connections shall be vapor
tight.
3-2-2-7
Separation from Propane ASTs
(a)
The minimum horizontal separation between an LP-Gas container and a Class I,
Class II or Class IIIA liquid storage tank installed after September 30, 1994
shall be 20 ft (6 m). When flammable or combustible liquids storage tanks are
within a diked area, the LP-Gas containers shall be outside the diked area and
at least 10 ft (3 m) away from the centerline of the wall of the diked area.
For all tanks, suitable measures shall be taken to prevent the accumulation of
Class I, Class II, or Class IIIA liquids under adjacent LP-Gas containers such
as by dikes, diversion curbs, or grading.
(b) Subsection (a) shall not apply when
LP-Gas containers of 125 gal (475 L) or less capacity are installed adjacent to
fuel oil supply tanks of 660 gal (2498 L) or less capacity. No horizontal
separation is required between aboveground LP-Gas containers and underground
flammable and combustible liquids tanks installed in accordance with UST
rules.
3-2-3
Installation, Upgrade, and Repairs
(a) Application for Permit for ASTs
(1) An application must be submitted to and
approved by the Director before beginning construction;
(i) On any new or used/reinstalled AST system
that will store a regulated substance; or
(ii) Before beginning construction on any
existing regulated substance AST system at a facility that is being upgraded to
the standards described in these regulations or applicable statutes.
(A) This requirement applies to alterations
made to tanks, piping, or equipment affecting their operation, to containment
(diking or impounding), and to the security provisions of
3-2-1(i)(5) or
(6).
[Note: Where a tank will be moved from and returned to its
original location in order to allow an alteration to its containment (e.g.,
changing from bare earthen diking to lined earth or concrete diking), or where
a tank will be moved to a new location outside of its current footprint, a
permanent closure must be performed in accordance with
3-4-2, and an application must be
submitted for its reinstallation. For tanks installed before October 1, 1994
that will be moved from and returned to their original location, requests for
variance from separation requirements of
3-2-2 that cannot be met must be
made in writing at the time of application.]
(2) The application must include:
(i) Site Plan - A dimensioned drawing of the
facility, showing the name and address of the facility, the location of
existing tanks and piping that will remain at the facility, as well as new
tanks and piping proposed in the application, the location of dispensers and
buildings at the facility, the location of loading/unloading facilities, the
location of guard posts and fences, the location of property lines, and the
location and names of streets adjacent to the facility; and
(ii) A written application, using the form
supplied by the Director, containing information about the proposed
construction.
[Note: If a used AST will be installed/reinstalled, the
requirements of
3-2-3(d) apply,
and the results of the required inspections and testing must be submitted with
the application.]
(b) AST Facility Inspections Required
(1) Except in emergencies, if underground
piping will be replaced or added to the AST system, the Director must be
notified at least 72 hours prior to beginning the air pressure/soap solution
test of the piping in order that an inspection of the system may be scheduled
at that time. Emergency situations will be dealt with individually by the
Director, possibly by delegation of the inspection.
(2) The Director will make an inspection of
the AST system, to verify that the facility was constructed according to plan.
This inspection will be as detailed as practicable, but does not exempt the
owner/operator from certifying that the installation was made according to all
the requirements of these regulations. The owner/operator shall provide the
Director with a 72 hour notice prior to the filling of the tank
system.
(c) Denial or
Revocation of Permit
(1) An AST permit
application may be denied or revoked if the AST installation or operation is
not in conformance with these AST regulations.
(2) An AST permit may be denied or revoked if
the AST permit application is not complete or is determined to be
inaccurate.
(3) An AST permit may
be revoked if the AST installation or operation is not in conformance with the
facts presented in the application.
(4) An AST permit may be revoked if an
inspection by the Director reveals that the construction performed is not in
accordance with the installation plan submitted for approval; and may be
revoked for failure to meet the operating or fire safety rules established by
these regulations.
(5) An AST system
permit is automatically revoked six months after the date of issue unless the
Director grants an extension in writing.
(6) Six months or later, after an AST permit
is issued, the permit may be modified by subsequent statutory or regulatory
changes.
(d)
Reinstallation of ASTs
(1) Used ASTs being
installed to store a regulated substance must meet the following requirements:
(i) The AST itself must meet all of the
fabrication, construction and performance requirements, and be equipped with
all of the required equipment listed in 3-2 of these regulations.
(ii) The tank must be inspected per
3-3-4 -2, and manufacturer
reinstallation/relocation requirements.
(iii) The AST installation and registration
requirements of
3-2-3 and
3-2-4.
(iv) Emergency relief vent devices must be
tested and certified to be in good working order.
(e) Upgrading AST Systems
The deadlines for the upgrading of AST systems that existed
prior to AST regulations being promulgated have expired. This section remains
in this revision for historical reference.
(1) On or before December 22, 1996, AST
systems must meet the requirements of these regulations or permanently close
the tanks in accordance with these regulations. The following requirements take
effect December 22, 1996:
(i) Each AST must
be sound and have an emergency relief venting device which is equivalent to
those described in these regulations. The owner/operator is required to provide
proof that the tank meets this requirement.
(ii) Secondary containment methods or devices
must be provided and in regular use at the facility as described in
3-3-1.
(iii) The facility must meet the security
requirements of
3-2-1(i).
(2) By December 22, 1998, certain
AST systems must be equipped with a solenoid valve or a vacuum-actuated shutoff
valve, with a shear section as described in
3-2-1(g).
[Note: In applying these requirements, the following
quotation will be carefully considered by the Director - "Existing plants,
equipment, buildings, structures, and installations for the storage, handling
or use of flammable or combustible liquids that are not in strict compliance
with the terms of this code may be continued in use at the discretion of the
Director provided they do not constitute a recognized hazard to life or
adjoining property. The existence of a situation that might result in an
explosion or sudden escalation of a fire, such as inadequate ventilation of
confined spaces, lack of adequate emergency venting of a tank, failure to
fireproof the supports of elevated tanks, or lack of drainage or dikes to
control spills, may constitute such a hazard."]
(f) Repairs Allowed
(1) If an AST system is damaged, it must be
repaired to meet applicable requirements, or be properly closed.
Owners/operators of AST systems must ensure that repairs will prevent releases
due to structural failure or corrosion as long as the AST system is used to
store regulated substances.
(2) The
repairs must meet the following requirements:
(i) Repairs to AST systems must be properly
conducted in accordance with a code of practice developed by a nationally
recognized association or an independent testing laboratory. [Note: The
following codes and standards may be used to comply with this section: National
Fire Protection Association Standard 30, "Flammable and Combustible Liquids
Code"; American Petroleum Institute Recommended Practice 2200, "Repairing Crude
Oil, Liquefied Petroleum Gas, and Product Pipelines"];
(ii) Above ground metal pipe that has
released product must be immediately repaired or replaced and appropriately
tested. [Note: repaired piping that has previously contained flammable liquid
must not be subjected to an air pressure test unless the piping has been
completely cleaned and rendered vapor free]
(iii) Underground metal pipe sections and
fittings connected to an AST that have released product as a result of
corrosion or other damage must be replaced immediately and protected from
future corrosion. Fiberglass pipes and fittings may be repaired in accordance
with the equipment manufacturer's specifications.
(iv) Repaired AST underground piping must be
tightness tested in accordance with
2-3-4 -3(a)(2)(i) within 30
calendar days following the date of the completion of the repair. New
replacement piping runs that have never contained product may be tested by an
air pressure/soap bubble test at 1.5 times operating pressure if inspected and
approved by the Director.
(3) If a release of regulated substance is
identified during repairs to AST system equipment, the owner/operator shall
report the release according to Article 4.
