[Title 40 CFR 60.112b]
[Code of Federal Regulations (annual edition) - July 1, 2009 Edition]
[Title 40 - PROTECTION OF ENVIRONMENT]
[Chapter I - ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)]
[Subchapter C - AIR PROGRAMS (CONTINUED)]
[Part 60 - STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES--]
[Subpart Kb - Standards of Performance for Volatile Organic Liquid Storage]
[Sec. 60.112b - Standard for volatile organic compounds (VOC).]
[From the U.S. Government Printing Office]


40PROTECTION OF ENVIRONMENT62009-07-012009-07-01falseStandard for volatile organic compounds (VOC).60.112bSec. 60.112bPROTECTION OF ENVIRONMENTENVIRONMENTAL PROTECTION AGENCY (CONTINUED)AIR PROGRAMS (CONTINUED)STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES--Standards of Performance for Volatile Organic Liquid Storage
Sec. 60.112b  Standard for volatile organic compounds (VOC).

    (a) The owner or operator of each storage vessel either with a 
design capacity greater than or equal to 151 m\3\ containing a VOL that, 
as stored, has a maximum true vapor pressure equal to or greater than 
5.2 kPa but less than 76.6 kPa or with a design capacity greater than or 
equal to 75 m\3\ but less than 151 m\3\ containing a VOL that, as 
stored, has a maximum true vapor pressure equal to or greater than 27.6 
kPa but less than 76.6 kPa, shall equip each storage vessel with one of 
the following:
    (1) A fixed roof in combination with an internal floating roof 
meeting the following specifications:
    (i) The internal floating roof shall rest or float on the liquid 
surface (but not necessarily in complete contact with it) inside a 
storage vessel that has a fixed roof. The internal floating roof shall 
be floating on the liquid surface at all times, except during initial 
fill and during those intervals when the storage vessel is completely 
emptied or subsequently emptied and refilled. When the roof is resting 
on the leg supports, the process of filling, emptying, or refilling 
shall be continuous and

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shall be accomplished as rapidly as possible.
    (ii) Each internal floating roof shall be equipped with one of the 
following closure devices between the wall of the storage vessel and the 
edge of the internal floating roof:
    (A) A foam- or liquid-filled seal mounted in contact with the liquid 
(liquid-mounted seal). A liquid-mounted seal means a foam- or liquid-
filled seal mounted in contact with the liquid between the wall of the 
storage vessel and the floating roof continuously around the 
circumference of the tank.
    (B) 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.
    (C) A mechanical shoe seal. A mechanical shoe seal is a metal sheet 
held vertically against the wall of the storage vessel by springs or 
weighted levers and is connected by braces to the floating roof. A 
flexible coated fabric (envelope) spans the annular space between the 
metal sheet and the floating roof.
    (iii) Each opening in a noncontact internal floating roof except for 
automatic bleeder vents (vacuum breaker vents) and the rim space vents 
is to provide a projection below the liquid surface.
    (iv) 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 is to be equipped with a cover or 
lid which is to be maintained in a closed position at all times (i.e., 
no visible gap) except when the device is in actual use. The cover or 
lid shall be equipped with a gasket. Covers on each access hatch and 
automatic gauge float well shall be bolted except when they are in use.
    (v) Automatic bleeder vents shall be equipped with a gasket and 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.
    (vi) Rim space vents shall be equipped with a gasket and are to be 
set to open only when the internal floating roof is not floating or at 
the manufacturer's recommended setting.
    (vii) Each penetration of the internal floating roof for the purpose 
of sampling shall be a sample well. The sample well shall have a slit 
fabric cover that covers at least 90 percent of the opening.
    (viii) 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.
    (ix) Each penetration of the internal floating roof that allows for 
passage of a ladder shall have a gasketed sliding cover.
    (2) An external floating roof. An external floating roof means a 
pontoon-type or double-deck type cover that rests on the liquid surface 
in a vessel with no fixed roof. Each external floating roof must meet 
the following specifications:
    (i) Each external floating roof shall be equipped with a closure 
device between the wall of the storage vessel and the roof edge. 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.
    (A) The primary seal shall be either a mechanical shoe seal or a 
liquid-mounted seal. Except as provided in Sec. 60.113b(b)(4), the seal 
shall completely cover the annular space between the edge of the 
floating roof and tank wall.
    (B) 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 except as allowed in Sec. 60.113b(b)(4).
    (ii) Except for automatic bleeder vents and rim space vents, each 
opening in a noncontact external floating roof shall provide a 
projection below the liquid surface. 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 that is to be 
maintained in a closed position at all times (i.e., no visible gap) 
except when the device is in actual use. 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

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being landed on the roof leg supports. Rim vents are to be set to open 
when the roof is being floated off the roof legs supports or at the 
manufacturer's recommended setting. Automatic bleeder vents and rim 
space vents are to be gasketed. Each emergency roof drain is to be 
provided with a slotted membrane fabric cover that covers at least 90 
percent of the area of the opening.
    (iii) The roof shall be floating on the liquid at all times (i.e., 
off the roof leg supports) except during initial fill until the roof is 
lifted off leg supports and when the tank is completely emptied and 
subsequently refilled. The process of filling, emptying, or refilling 
when the roof is resting on the leg supports shall be continuous and 
shall be accomplished as rapidly as possible.
    (3) A closed vent system and control device meeting the following 
specifications:
    (i) The closed vent system shall be designed to collect all VOC 
vapors and gases discharged from the storage vessel and operated with no 
detectable emissions as indicated by an instrument reading of less than 
500 ppm above background and visual inspections, as determined in part 
60, subpart VV, Sec. 60.485(b).
    (ii) The control device shall be designed and operated to reduce 
inlet VOC emissions 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 (Sec. 60.18) of the General 
Provisions.
    (4) A system equivalent to those described in paragraphs (a)(1), 
(a)(2), or (a)(3) of this section as provided in Sec. 60.114b of this 
subpart.
    (b) The owner or operator of each storage vessel with a design 
capacity greater than or equal to 75 m\3\ which contains a VOL that, as 
stored, has a maximum true vapor pressure greater than or equal to 76.6 
kPa shall equip each storage vessel with one of the following:
    (1) A closed vent system and control device as specified in Sec. 
60.112b(a)(3).
    (2) A system equivalent to that described in paragraph (b)(1) as 
provided in Sec. 60.114b of this subpart.
    (c) Site-specific standard for Merck & Co., Inc.'s Stonewall Plant 
in Elkton, Virginia. This paragraph applies only to the pharmaceutical 
manufacturing facility, commonly referred to as the Stonewall Plant, 
located at Route 340 South, in Elkton, Virginia (``site'').
    (1) For any storage vessel that otherwise would be subject to the 
control technology requirements of paragraphs (a) or (b) of this 
section, the site shall have the option of either complying directly 
with the requirements of this subpart, or reducing the site-wide total 
criteria pollutant emissions cap (total emissions cap) in accordance 
with the procedures set forth in a permit issued pursuant to 40 CFR 
52.2454. If the site chooses the option of reducing the total emissions 
cap in accordance with the procedures set forth in such permit, the 
requirements of such permit shall apply in lieu of the otherwise 
applicable requirements of this subpart for such storage vessel.
    (2) For any storage vessel at the site not subject to the 
requirements of 40 CFR 60.112b (a) or (b), the requirements of 40 CFR 
60.116b (b) and (c) and the General Provisions (subpart A of this part) 
shall not apply.

[52 FR 11429, Apr. 8, 1987, as amended at 62 FR 52641, Oct. 8, 1997]