[Code of Federal Regulations]
[Title 40, Volume 9]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR63.119]

[Page 221-226]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 63_NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS
 
    Subpart G_National Emission Standards for Organic Hazardous Air 
 Pollutants From the Synthetic Organic Chemical Manufacturing Industry 
 for Process Vents, Storage Vessels, Transfer Operations, and Wastewater
 
Sec.  63.119  Storage vessel provisions--reference control technology.

    (a) For each storage vessel to which this subpart applies, the owner 
or operator shall comply with the requirements of paragraphs (a)(1), 
(a)(2), (a)(3), and (a)(4) of this section according to the schedule 
provisions of Sec.  63.100 of subpart F of this part.
    (1) For each Group 1 storage vessel (as defined in table 5 of this 
subpart for existing sources and table 6 of the subpart for new sources) 
storing a liquid for which the maximum true vapor pressure of the total 
organic hazardous air pollutants in the liquid is less than 76.6 
kilopascals, the owner or operator shall reduce hazardous air pollutants 
emissions to the atmosphere either by operating and maintaining a fixed 
roof and internal floating roof, an external floating roof, an external 
floating roof converted to an internal floating roof, a closed vent 
system and control device, routing the emissions to a process or a fuel 
gas system, or vapor balancing in accordance with the requirements in 
paragraph (b), (c), (d), (e), (f), or (g) of this section, or equivalent 
as provided in Sec.  63.121 of this subpart.
    (2) For each Group 1 storage vessel (as defined in table 5 of this 
subpart for existing sources and table 6 of this subpart for new 
sources) storing a liquid for which the maximum true vapor pressure of 
the total organic hazardous air pollutants in the liquid is greater than 
or equal to 76.6 kilopascals, the owner or operator shall operate and 
maintain a closed vent system and control device meeting the 
requirements specified in paragraph (e) of this section, route the 
emissions to a process or a fuel gas system as specified in paragraph 
(f) of this section, vapor balance as specified in paragraph (g) of this 
section, or equivalent as provided in Sec.  63.121 of this subpart.
    (3) For each Group 2 storage vessel that is not part of an emissions 
average as described in Sec.  63.150 of this subpart, the owner or 
operator shall comply with the recordkeeping requirement in Sec.  
63.123(a) of this subpart and is not required to comply with any other 
provisions in Sec. Sec.  63.119 through 63.123 of this subpart.
    (4) For each Group 2 storage vessel that is part of an emissions 
average, the owner or operator shall comply with the emissions averaging 
provisions in Sec.  63.150 of this subpart.
    (b) The owner or operator who elects to use a fixed roof and an 
internal floating roof, as defined in Sec.  63.111 of this subpart, to 
comply with the requirements of paragraph (a)(1) of this section shall 
comply with the requirements specified in paragraphs (b)(1) through 
(b)(6) of this section.
    Note: The intent of paragraphs (b)(1) and (b)(2) of this section is 
to avoid having a vapor space between the floating roof and the stored 
liquid for extended periods. Storage vessels may be emptied for purposes 
such as routine storage vessel maintenance, inspections, petroleum 
liquid deliveries, or transfer operations. Storage vessels where liquid 
is left on walls, as bottom clingage, or in pools due to floor 
irregularity are considered completely empty.
    (1) The internal floating roof shall be floating on the liquid 
surface at all times except when the floating roof must be supported by 
the leg supports during the periods specified in paragraphs (b)(1)(i) 
through (b)(1)(iii) of this section.
    (i) During the initial fill.
    (ii) After the vessel has been completely emptied and degassed.
    (iii) When the vessel is completely emptied before being 
subsequently refilled.
    (2) When the floating roof is resting on the leg supports, the 
process of filling, emptying, or refilling shall be continuous and shall 
be accomplished as soon as practical.
    (3) Each internal floating roof shall be equipped with a closure 
device between the wall of the storage vessel and the roof edge. Except 
as provided

[[Page 222]]

in paragraph (b)(3)(iv) of this section, the closure device shall 
consist of one of the devices listed in paragraph (b)(3)(i), (b)(3)(ii), 
or (b)(3)(iii) of this section.
    (i) A liquid-mounted seal as defined in Sec.  63.111 of this 
subpart.
    (ii) A metallic shoe seal as defined in Sec.  63.111 of this 
subpart.
    (iii) Two seals mounted one above the other so that each forms a 
continuous closure that completely covers the space between the wall of 
the storage vessel and the edge of the internal floating roof. The lower 
seal may be vapor- mounted, but both must be continuous seals.
    (iv) If the internal floating roof is equipped with a vapor-mounted 
seal as of December 31, 1992, the requirement for one of the seal 
options specified in paragraphs (b)(3)(i), (b)(3)(ii), and (b)(3)(iii) 
of this section does not apply until the earlier of the dates specified 
in paragraphs (b)(3)(iv)(A) and (b)(3)(iv)(B) of this section.
    (A) The next time the storage vessel is emptied and degassed.
    (B) No later than 10 years after April 22, 1994.
    (4) Automatic bleeder vents are to be closed at all times when the 
roof is floating, except when the roof is being floated off or is being 
landed on the roof leg supports.
    (5) Except as provided in paragraph (b)(5)(viii) of this section, 
each internal floating roof shall meet the specifications listed in 
paragraphs (b)(5)(i) through (b)(5)(vii) of this section.
    (i) Each opening in a noncontact internal floating roof except for 
automatic bleeder vents (vacuum breaker vents) and rim space vents is to 
provide a projection below the liquid surface.
    (ii) Each opening in the internal floating roof except for leg 
sleeves, automatic bleeder vents, rim space vents, column wells, ladder 
wells, sample wells, and stub drains shall be equipped with a cover or 
lid. The cover or lid shall be equipped with a gasket.
    (iii) Each penetration of the internal floating roof for the 
purposes of sampling shall be a sample well. Each sample well shall have 
a slit fabric cover that covers at least 90 percent of the opening.
    (iv) Each automatic bleeder vent shall be gasketed.
    (v) Each rim space vent shall be gasketed.
    (vi) Each penetration of the internal floating roof that allows for 
passage of a ladder shall have a gasketed sliding cover.
    (vii) Each penetration of the internal floating roof that allows for 
passage of a column supporting the fixed roof shall have a flexible 
fabric sleeve seal or a gasketed sliding cover.
    (viii) If the internal floating roof does not meet any one of the 
specifications listed in paragraphs (b)(5)(i) through (b)(5)(vii) of 
this section as of December 31, 1992, the requirement for meeting those 
specifications does not apply until the earlier of the dates specified 
in paragraphs (b)(5)(viii)(A) and (b)(5)(viii)(B) of this section.
    (A) The next time the storage vessel is emptied and degassed.
    (B) No later than 10 years after April 22, 1994.
    (6) Each cover or lid on any opening in the internal floating roof 
shall be closed (i.e., no visible gaps), except when the cover or lid 
must be open for access. Covers on each access hatch and each gauge 
float well shall be bolted or fastened so as to be air-tight when they 
are closed. Rim space vents are to be set to open only when the internal 
floating roof is not floating or when the pressure beneath the rim seal 
exceeds the manufacturer's recommended setting.
    (c) The owner or operator who elects to use an external floating 
roof, as defined in Sec.  63.111 of this subpart, to comply with the 
requirements of paragraph (a)(1) of this section shall comply with the 
requirements specified in paragraphs (c)(1) through (c)(4) of this 
section.
    (1) Each external floating roof shall be equipped with a closure 
device between the wall of the storage vessel and the roof edge.
    (i) Except as provided in paragraph (c)(1)(iv) of this section, the 
closure device is to consist of two seals, one above the other. The 
lower seal is referred to as the primary seal and the upper seal is 
referred to as the secondary seal.

[[Page 223]]

    (ii) Except as provided in paragraph (c)(1)(v) of this section, the 
primary seal shall be either a metallic shoe seal or a liquid-mounted 
seal.
    (iii) Except during the inspections required by Sec.  63.120(b) of 
this subpart, both the primary seal and the secondary seal shall 
completely cover the annular space between the external floating roof 
and the wall of the storage vessel in a continuous fashion.
    (iv) If the external floating roof is equipped with a liquid-mounted 
or metallic shoe primary seal as of December 31, 1992, the requirement 
for a secondary seal in paragraph (c)(1)(i) of this section does not 
apply until the earlier of the dates specified in paragraphs 
(c)(1)(iv)(A) and (c)(1)(iv)(B) of this section.
    (A) The next time the storage vessel is emptied and degassed.
    (B) No later than 10 years after April 22, 1994.
    (v) If the external floating roof is equipped with a vapor-mounted 
primary seal and a secondary seal as of December 31, 1992, the 
requirement for a liquid-mounted or metallic shoe primary seal in 
paragraph (c)(1)(ii) of this section does not apply until the earlier of 
the dates specified in paragraphs (c)(1)(v)(A) and (c)(1)(v)(B) of this 
section.
    (A) The next time the storage vessel is emptied and degassed.
    (B) No later than 10 years after April 22, 1994.
    (2) Each external floating roof shall meet the specifications listed 
in paragraphs (c)(2)(i) through (c)(2)(xii) of this section.
    (i) Except for automatic bleeder vents (vacuum breaker vents) and 
rim space vents, each opening in the noncontact external floating roof 
shall provide a projection below the liquid surface except as provided 
in paragraph (c)(2)(xii) of this section.
    (ii) Except for automatic bleeder vents, rim space vents, roof 
drains, and leg sleeves, each opening in the roof is to be equipped with 
a gasketed cover, seal or lid which is to be maintained in a closed 
position (i.e., no visible gap) at all times except when the cover or 
lid must be open for access. Covers on each access hatch and each gauge 
float well shall be bolted or fastened so as to be air-tight when they 
are closed.
    (iii) Automatic bleeder vents are to be closed at all times when the 
roof is floating, except when the roof is being floated off or is being 
landed on the roof leg supports.
    (iv) Rim space vents are to be set to open only when the roof is 
being floated off the roof leg supports or when the pressure beneath the 
rim seal exceeds the manufacturer's recommended setting.
    (v) Automatic bleeder vents and rim space vents are to be gasketed.
    (vi) Each roof drain that empties into the stored liquid is to be 
provided with a slotted membrane fabric cover that covers at least 90 
percent of the area of the opening.
    (vii) Each unslotted guide pole well shall have a gasketed sliding 
cover or a flexible fabric sleeve seal.
    (viii) Each unslotted guide pole shall have on the end of the pole a 
gasketed cap which is closed at all times except when gauging the liquid 
level or taking liquid samples.
    (ix) Each slotted guide pole well shall have a gasketed sliding 
cover or a flexible fabric sleeve seal.
    (x) Each slotted guide pole shall have a gasketed float or other 
device which closes off the liquid surface from the atmosphere.
    (xi) Each gauge hatch/sample well shall have a gasketed cover which 
is closed at all times except when the hatch or well must be open for 
access.
    (xii) If each opening in a noncontact external floating roof except 
for automatic bleeder vents (vacuum breaker vents) and rim space vents 
does not provide a projection below the liquid surface as of December 
31, 1992, the requirement for providing these projections below the 
liquid surface does not apply until the earlier of the dates specified 
in paragraphs (c)(2)(xii)(A) and (c)(2)(xii)(B) of this section.
    (A) The next time the storage vessel is emptied and degassed.
    (B) No later than 10 years after April 22, 1994.
    Note: The intent of paragraphs (c)(3) and (c)(4) of this section is 
to avoid having a vapor space between the floating roof and the stored 
liquid for extended periods. Storage vessels may be emptied for purposes 
such

[[Page 224]]

as routine storage vessel maintenance, inspections, petroleum liquid 
deliveries, or transfer operations. Storage vessels where liquid is left 
on walls, as bottom clingage, or in pools due to floor irregularity are 
considered completely empty.
    (3) The external floating roof shall be floating on the liquid 
surface at all times except when the floating roof must be supported by 
the leg supports during the periods specified in paragraphs (c)(3)(i) 
through (c)(3)(iii) of this section.
    (i) During the initial fill.
    (ii) After the vessel has been completely emptied and degassed.
    (iii) When the vessel is completely emptied before being 
subsequently refilled.
    (4) When the floating roof is resting on the leg supports, the 
process of filling, emptying, or refilling shall be continuous and shall 
be accomplished as soon as practical.
    (d) The owner or operator who elects to use an external floating 
roof converted to an internal floating roof (i.e., fixed roof installed 
above external floating roof) to comply with paragraph (a)(1) of this 
section shall comply with paragraphs (d)(1) and (d)(2) of this section.
    (1) Comply with the requirements for internal floating roof vessels 
specified in paragraphs (b)(1), (2), and (3) of this section; and
    (2) Comply with the requirements for deck fittings that are 
specified for external floating roof vessels in paragraphs (c)(2)(i) 
through (c)(2)(xii) of this section.
    (e) The owner or operator who elects to use a closed vent system and 
control device, as defined in Sec.  63.111 of this subpart, to comply 
with the requirements of paragraph (a)(1) or (a)(2) of this section 
shall comply with the requirements specified in paragraphs (e)(1) 
through (e)(5) of this section.
    (1) Except as provided in paragraph (e)(2) of this section, the 
control device shall be designed and operated to reduce inlet emissions 
of total organic HAP by 95 percent or greater. If a flare is used as the 
control device, it shall meet the specifications described in the 
general control device requirements of Sec.  63.11(b) of subpart A of 
this part.
    (2) If the owner or operator can demonstrate that a control device 
installed on a storage vessel on or before December 31, 1992 is designed 
to reduce inlet emissions of total organic HAP by greater than or equal 
to 90 percent but less than 95 percent, then the control device is 
required to be operated to reduce inlet emissions of total organic HAP 
by 90 percent or greater.
    (3) Periods of planned routine maintenance of the control device, 
during which the control device does not meet the specifications of 
paragraph (e)(1) or (e)(2) of this section, as applicable, shall not 
exceed 240 hours per year.
    (4) The specifications and requirements in paragraphs (e)(1) and 
(e)(2) of this section for control devices do not apply during periods 
of planned routine maintenance.
    (5) The specifications and requirements in paragraphs (e)(1) and 
(e)(2) of this section for control devices do not apply during a control 
system malfunction.
    (6) An owner or operator may use a combination of control devices to 
achieve the required reduction of total organic hazardous air pollutants 
specified in paragraph (e)(1) of this section. An owner or operator may 
use a combination of control devices installed on a storage vessel on or 
before December 31, 1992 to achieve the required reduction of total 
organic hazardous air pollutants specified in paragraph (e)(2) of this 
section.
    (f) The owner or operator who elects to route emissions to a fuel 
gas system or to a process, as defined in Sec.  63.111 of this subpart, 
to comply with the requirements of paragraph (a)(1) or (a)(2) of this 
section shall comply with the requirements in paragraphs (f)(1) through 
(f)(3) of this section, as applicable.
    (1) If emissions are routed to a fuel gas system, there is no 
requirement to conduct a performance test or design evaluation. If 
emissions are routed to a process, the organic hazardous air pollutants 
in the emissions shall predominantly meet one of, or a combination of, 
the ends specified in paragraphs (f)(1)(i) through (f)(1)(iv) of this 
section. The owner or operator shall comply with the compliance 
demonstration requirements in Sec.  63.120(f).

[[Page 225]]

    (i) Recycled and/or consumed in the same manner as a material that 
fulfills the same function in that process;
    (ii) Transformed by chemical reaction into materials that are not 
organic hazardous air pollutants;
    (iii) Incorporated into a product; and/or
    (iv) Recovered.
    (2) If the emissions are conveyed by a system other than hard-
piping, any conveyance system operated under positive pressure shall be 
subject to the requirements of Sec.  63.148 of this subpart.
    (3) The fuel gas system or process shall be operating at all times 
when organic hazardous air pollutants emissions are routed to it except 
as provided in Sec.  63.102(a)(1) of subpart F of this part and in 
paragraphs (f)(3)(i) through (f)(3)(iii) of this section. Whenever the 
owner or operator by-passes the fuel gas system or process, the owner or 
operator shall comply with the recordkeeping requirement in Sec.  
63.123(h) of this subpart. Bypassing is permitted if the owner or 
operator complies with one or more of the conditions specified in 
paragraphs (f)(3)(i) through (f)(3)(iii) of this section.
    (i) The liquid level in the storage vessel is not increased;
    (ii) The emissions are routed through a closed-vent system to a 
control device complying with Sec.  63.119(e) of this subpart; or
    (iii) The total aggregate amount of time during which the emissions 
by-pass the fuel gas system or process during the calendar year without 
being routed to a control device, for all reasons (except start-ups/
shutdowns/malfunctions or product changeovers of flexible operation 
units and periods when the storage vessel has been emptied and 
degassed), does not exceed 240 hours.
    (g) The owner or operator who elects to vapor balance to comply with 
the requirements of paragraphs (a)(1) and (2) of this section shall 
comply with paragraphs (g)(1) through (7) of this section and the 
recordkeeping requirements of Sec.  63.123(i).
    (1) The vapor balancing system must be designed and operated to 
route organic HAP vapors displaced from loading of the storage tank to 
the railcar, tank truck, or barge from which the storage tank is filled.
    (2) Tank trucks and railcars must have a current certification in 
accordance with the U.S. Department of Transportation pressure test 
requirements of 49 CFR part 180 for tank trucks and 49 CFR 173.31 for 
railcars. Barges must have a current certification of vapor-tightness 
through testing in accordance with 40 CFR 63.565.
    (3) Hazardous air pollutants must only be unloaded from tank trucks 
or railcars when vapor collection systems are connected to the storage 
tank's vapor collection system.
    (4) No pressure relief device on the storage tank, or on the railcar 
or tank truck, shall open during loading or as a result of diurnal 
temperature changes (breathing losses).
    (5) Pressure relief devices must be set to no less than 2.5 psig at 
all times to prevent breathing losses. Pressure relief devices may be 
set at values less than 2.5 psig if the owner or operator provides 
rationale in the notification of compliance status report explaining why 
the alternative value is sufficient to prevent breathing losses at all 
times. The owner or operator shall comply with paragraphs (g)(5)(i) 
through (iii) of this section for each pressure relief valve.
    (i) The pressure relief valve shall be monitored quarterly using the 
method described in Sec.  63.180(b).
    (ii) An instrument reading of 500 ppmv or greater defines a leak.
    (iii) When a leak is detected, it shall be repaired as soon as 
practicable, but no later than 5 days after it is detected, and the 
owner or operator shall comply with the recordkeeping requirements of 
Sec.  63.181(d)(1) through (4).
    (6) Railcars, tank trucks, or barges that deliver HAP to a storage 
tank must be reloaded or cleaned at a facility that utilizes the control 
techniques specified in paragraph (g)(6)(i) or (ii) of this section.
    (i) The railcar, tank truck, or barge must be connected to a closed-
vent system with a control device that reduces inlet emissions of HAP by 
95 percent by weight or greater.
    (ii) A vapor balancing system designed and operated to collect 
organic HAP vapor displaced from the tank

[[Page 226]]

truck, railcar, or barge during reloading must be used to route the 
collected HAP vapor to the storage tank from which the liquid being 
transferred originated.
    (7) The owner or operator of the facility where the railcar, tank 
truck, or barge is reloaded or cleaned must comply with paragraphs 
(g)(7)(i) through (iii) of this section.
    (i) Submit to the owner or operator of the storage tank and to the 
Administrator a written certification that the reloading or cleaning 
facility will meet the requirements of this section. The certifying 
entity may revoke the written certification by sending a written 
statement to the owner or operator of the storage tank giving at least 
90 days notice that the certifying entity is rescinding acceptance of 
responsibility for compliance with the requirements of this paragraph 
(g)(7).
    (ii) If complying with paragraph (g)(6)(i) of this section, comply 
with the requirements for closed vent system and control device 
specified in Sec. Sec.  63.119 through 63.123. The notification and 
reporting requirements in Sec.  63.122 do not apply to the owner or 
operator of the offsite cleaning or reloading facility.
    (iii) If complying with paragraph (g)(6)(ii) of this section, keep 
the records specified in Sec.  63.123(i)(3).
    (iv) After the compliance dates specified in Sec.  63.100(k) at an 
offsite reloading or cleaning facility subject to paragraph (g) of this 
section, compliance with the monitoring, recordkeeping, and reporting 
provisions of any other subpart of this part 63 constitutes compliance 
with the monitoring, recordkeeping, and reporting provisions of 
paragraph (g)(7)(ii) or paragraph (g)(7)(iii) of this section. You must 
identify in your Notification of Compliance Status report required by 
Sec.  63.152(b), the subpart to the part 63 with which the owner or 
operator of the reloading or cleaning facility complies.

[59 FR 19468, Apr. 22, 1994, as amended at 62 FR 2747, Jan. 17, 1997; 69 
FR 76863, Dec. 23, 2004; 71 FR 76614, Dec. 21, 2006]