| (D) Any external floating roof drain that empties into
the stored liquid must be equipped with a slotted membrane fabric
cover that covers at least 90% of the area of the opening or an equivalent
control that must be kept in a closed (i.e., no gap of more than 1/8
inch) position at all times except when the drain is in actual use.
Stub drains on an internal floating roof storage tank are not subject
to this requirement.
(E) There must be no visible holes, tears, or other
openings in any seal or seal fabric.
(F) For an external floating roof storage tank, secondary
seals must be the rim-mounted type (the seal must be continuous from
the floating roof to the tank wall with the exception of gaps that
do not exceed the following specification). The accumulated area of
gaps that exceed 1/8 inch in width between the secondary seal and
storage tank wall may not be greater than 1.0 square inch per foot
of storage tank diameter.
(G) Each opening for a slotted guidepole in an external
floating roof storage tank must be equipped with one of the following
control device configurations:
(i) a pole wiper and pole float that has a seal or
wiper at or above the height of the pole wiper;
(ii) a pole wiper and a pole sleeve;
(iii) an internal sleeve emission control system;
(iv) a retrofit to a solid guidepole system;
(v) a flexible enclosure system; or
(vi) a cover on an external floating roof tank.
(H) The external floating roof or internal floating
roof must be floating on the liquid surface at all times except as
specified in this subparagraph. The external floating roof or internal
floating roof may be supported by the leg supports or other support
devices, such as hangers from the fixed roof, during the initial fill
or refill after the storage tank has been cleaned or as allowed under
the following circumstances:
(i) when necessary for maintenance or inspection;
(ii) when necessary for supporting a change in service
to an incompatible liquid;
(iii) when the storage tank has a storage capacity
less than 25,000 gallons or the vapor pressure of the material stored
is less than 1.5 psia;
(iv) when the vapors are routed to a control device
from the time the floating roof is landed until the floating roof
is within ten percent by volume of being refloated;
(v) when all VOC emissions from the tank, including
emissions from roof landings, have been included in a floating roof
storage tank emissions limit or cap approved under Chapter 116 of
this title (relating to Control of Air Pollution by Permits for New
Construction or Modification); or
(vi) when all VOC emissions from floating roof landings
at the regulated entity, as defined in §101.1 of this title (relating
to Definitions), are less than 25 tons per year.
(3) Vapor control systems, as defined in §115.10
of this title, used as a control device on any storage tank must maintain
a minimum control efficiency of 90%.
(4) For a storage tank storing condensate, as defined
in §101.1 of this title, prior to custody transfer, flashed gases
must be routed to a vapor control system if the liquid throughput
through an individual tank or the aggregate of tanks in a tank battery
exceeds 1,500 barrels (63,000 gallons) per year.
(5) For a storage tank storing crude oil or condensate
prior to custody transfer or at a pipeline breakout station, flashed
gases must be routed to a vapor control system if the uncontrolled
VOC emissions from an individual storage tank, or from the aggregate
of storage tanks in a tank battery, equal or exceed 25 tons per year
on a rolling 12-month basis. Uncontrolled emissions must be estimated
by one of the following methods; however, if emissions determined
using direct measurements or other methods approved by the executive
director under subparagraph (A) or (D) of this paragraph are higher
than emissions estimated using the default factors or charts in subparagraph
(B) or (C) of this paragraph, the higher values must be used.
(A) The owner or operator may make direct measurements
using the measuring instruments and methods specified in §115.117
of this title (relating to Approved Test Methods).
(B) The owner or operator may use a factor of 33.3
pounds of VOC per barrel (42 gallons) of condensate produced or 1.6
pounds of VOC per barrel (42 gallons) of oil produced.
(C) For crude oil storage only, the owner or operator
may use the chart in Exhibit 2 of the United States Environmental
Protection Agency publication Lessons Learned
from Natural Gas Star Partners: Installing Vapor Recovery Units on
Crude Oil Storage Tanks, October 2003, and assuming that the
hydrocarbon vapors have a molecular weight of 34 pounds per pound
mole and are 48% by weight VOC.
(D) Other test methods or computer simulations may
be allowed if approved by the executive director.
(e) The control requirements in this subsection apply
in the Houston-Galveston-Brazoria and Dallas-Fort Worth areas, except
as specified in §115.119 of this title (relating to Compliance
Schedules) and in paragraph (3) of this subsection. Beginning January
1, 2023, the requirements in this subsection no longer apply to storage
tanks storing crude oil or condensate that are subject to Division
7 of this subchapter (relating to Oil and Natural Gas Service in Ozone
Nonattainment Areas).
(1) No person shall place, store, or hold VOC in any
storage tank unless the storage tank is capable of maintaining working
pressure sufficient at all times to prevent any vapor or gas loss
to the atmosphere or is in compliance with the control requirements
specified in Table 1 of this paragraph for VOC other than crude oil
and condensate or Table 2 of this paragraph for crude oil and condensate.
Attached Graphic
(2) For an external floating roof or internal floating
roof storage tank subject to the provisions of paragraph (1) of this
subsection, the following requirements apply.
(A) All openings in an internal floating roof or external
floating roof must provide a projection below the liquid surface.
Automatic bleeder vents (vacuum breaker vents) and rim space vents
are not subject to this requirement.
(B) All openings in an internal floating roof or external
floating roof must be equipped with a deck cover. The deck cover must
be equipped with a gasket in good operating condition between the
cover and the deck. The deck cover must be closed (i.e., no gap of
more than 1/8 inch) at all times, except when the cover must be open
for access. Automatic bleeder vents (vacuum breaker vents), rim space
vents, leg sleeves, and roof drains are not subject to this requirement.
(C) Automatic bleeder vents (vacuum breaker vents)
and rim space vents must be equipped with a gasketed lid, pallet,
flapper, or other closure device and must be closed (i.e., no gap
of more than 1/8 inch) at all times except when required to be open
to relieve excess pressure or vacuum in accordance with the manufacturer's
design.
(D) Each opening into the internal floating roof for
a fixed roof support column may be equipped with a flexible fabric
sleeve seal instead of a deck cover.
(E) Any external floating roof drain that empties into
the stored liquid must be equipped with a slotted membrane fabric
cover that covers at least 90% of the area of the opening or an equivalent
control that must be kept in a closed (i.e., no gap of more than 1/8
inch) position at all times except when the drain is in actual use.
Stub drains on an internal floating roof storage tank are not subject
to this requirement.
(F) There must be no visible holes, tears, or other
openings in any seal or seal fabric.
(G) For an external floating roof storage tank, secondary
seals must be the rim-mounted type. The seal must be continuous from
the floating roof to the tank wall with the exception of gaps that
do not exceed the following specification. The accumulated area of
gaps that exceed 1/8 inch in width between the secondary seal and
storage tank wall may not be greater than 1.0 square inch per foot
of storage tank diameter.
(H) Each opening for a slotted guidepole in an external
floating roof storage tank must be equipped with one of the following
control device configurations:
(i) a pole wiper and pole float that has a seal or
wiper at or above the height of the pole wiper;
(ii) a pole wiper and a pole sleeve;
(iii) an internal sleeve emission control system;
(iv) a retrofit to a solid guidepole system;
(v) a flexible enclosure system; or
(vi) a cover on an external floating roof tank.
(I) The external floating roof or internal floating
roof must be floating on the liquid surface at all times except as
allowed under the following circumstances:
Cont'd... |
