[Code of Federal Regulations]
[Title 40, Volume 11]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR63.1271]

[Page 223-226]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 63_NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR 
 
  Subpart HHH_National Emission Standards for Hazardous Air Pollutants 
          From Natural Gas Transmission and Storage Facilities
 
Sec.  63.1271  Definitions.

    All terms used in this subpart shall have the meaning given to them 
in the Clean Air Act, subpart A of this part (General Provisions), and 
in this section. If the same term is defined in subpart A and in this 
section, it shall have the meaning given in this section for purposes of 
this subpart.
    Boiler means an enclosed device using controlled flame combustion 
and having the primary purpose of recovering and exporting thermal 
energy in the form of steam or hot water. Boiler also means any 
industrial furnace as defined in 40 CFR 260.10.
    Closed-vent system means a system that is not open to the atmosphere 
and is composed of piping, ductwork, connections, and if necessary, flow 
inducing devices that transport gas or vapor from an emission point to 
one or more control devices. If gas or vapor from regulated equipment is 
routed to a process (e.g., to a fuel gas system), the conveyance system 
shall not be considered a closed-vent system and is not subject to 
closed-vent system standards.
    Combustion device means an individual unit of equipment, such as a 
flare, incinerator, process heater, or boiler, used for the combustion 
of organic HAP emissions.

[[Page 224]]

    Compressor station means any permanent combination of compressors 
that move natural gas at increased pressure from fields, in transmission 
pipelines, or into storage.
    Continuous recorder means a data recording device that either 
records an instantaneous data value at least once every hour or records 
hourly or more frequent block average values.
    Control device means any equipment used for recovering or oxidizing 
HAP or volatile organic compound (VOC) vapors. Such equipment includes, 
but is not limited to, absorbers, carbon absorbers, condensers, 
incinerators, flares, boilers, and process heaters. For the purposes of 
this subpart, if gas or vapor from regulated equipment is used, reused 
(i.e., injected into the flame zone of an enclosed combustion device), 
returned back to the process, or sold, then the recovery system used, 
including piping, connections, and flow inducing devices, is not 
considered to be a control device or a closed-vent system.
    Custody transfer means the transfer of natural gas after processing 
and/or treatment in the production operations to pipelines or any other 
forms of transportation.
    Facility means any grouping of equipment where natural gas is 
processed, compressed, or stored prior to entering a pipeline to a local 
distribution company or (if there is no local distribution company) to a 
final end user. Examples of a facility for this source category are: an 
underground natural gas storage operation; or a natural gas compressor 
station that receives natural gas via pipeline, from an underground 
natural gas storage operation, or from a natural gas processing plant. 
The emission points associated with these phases include, but are not 
limited to, process vents. Processes that may have vents include, but 
are not limited to, dehydration and compressor station engines.
    Facility, for the purpose of a major source determination, means 
natural gas transmission and storage equipment that is located inside 
the boundaries of an individual surface site (as defined in this 
section) and is connected by ancillary equipment, such as gas flow lines 
or power lines. Equipment that is part of a facility will typically be 
located within close proximity to other equipment located at the same 
facility. Natural gas transmission and storage equipment or groupings of 
equipment located on different gas leases, mineral fee tracts, lease 
tracts, subsurface unit areas, surface fee tracts, or surface lease 
tracts shall not be considered part of the same facility.
    Flame zone means the portion of the combustion chamber in a 
combustion device occupied by the flame envelope.
    Flash tank. See the definition for gas-condensate-glycol (GCG) 
separator.
    Flow indicator means a device which indicates whether gas flow is 
present in a line or whether the valve position would allow gas flow to 
be present in a line.
    Gas-condensate-glycol (GCG) separator means a two-or three-phase 
separator through which the ``rich'' glycol stream of a glycol 
dehydration unit is passed to remove entrained gas and hydrocarbon 
liquid. The GCG separator is commonly referred to as a flash separator 
or flash tank.
    Glycol dehydration unit means a device in which a liquid glycol 
(including, but not limited to, ethylene glycol, diethylene glycol, or 
triethylene glycol) absorbent directly contacts a natural gas stream and 
absorbs water in a contact tower or absorption column (absorber). The 
glycol contacts and absorbs water vapor and other gas stream 
constituents from the natural gas and becomes ``rich'' glycol. This 
glycol is then regenerated in the glycol dehydration unit reboiler. The 
``lean'' glycol is then recycled.
    Glycol dehydration unit baseline operations means operations 
representative of the glycol dehydration unit operations as of June 17, 
1999. For the purposes of this subpart, for determining the percentage 
of overall HAP emission reduction attributable to process modifications, 
glycol dehydration unit baseline operations shall be parameter values 
(including, but not limited to, glycol circulation rate or glycol-HAP 
absorbency) that represent actual long-term conditions (i.e., at least 1 
year). Glycol dehydration units in operation for less than 1 year shall 
document that the parameter values represent

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expected long-term operating conditions had process modifications not 
been made.
    Glycol dehydration unit process vent means the glycol dehydration 
unit reboiler vent and the vent from the GCG separator (flash tank), if 
present.
    Glycol dehydration unit reboiler vent means the vent through which 
exhaust from the reboiler of a glycol dehydration unit passes from the 
reboiler to the atmosphere or to a control device.
    Hazardous air pollutants or HAP means the chemical compounds listed 
in section 112(b) of the Clean Air Act (Act). All chemical compounds 
listed in section 112(b) of the Act need to be considered when making a 
major source determination. Only the HAP compounds listed in Table 1 of 
this subpart need to be considered when determining compliance.
    Incinerator means an enclosed combustion device that is used for 
destroying organic compounds. Auxiliary fuel may be used to heat waste 
gas to combustion temperatures. Any energy recovery section is not 
physically formed into one manufactured or assembled unit with the 
combustion section; rather, the energy recovery section is a separate 
section following the combustion section and the two are joined by ducts 
or connections carrying flue gas. The above energy recovery section 
limitation does not apply to an energy recovery section used solely to 
preheat the incoming vent stream or combustion air.
    Initial startup means the first time a new or reconstructed source 
begins production. For the purposes of this subpart, initial startup 
does not include subsequent startups (as defined in this section) of 
equipment, for example, following malfunctions or shutdowns.
    Major source, as used in this subpart, shall have the same meaning 
as in Sec.  63.2, except that:
    (1) Emissions from any pipeline compressor station or pump station 
shall not be aggregated with emissions from other similar units, whether 
or not such units are in a contiguous area or under common control; and
    (2) Emissions from processes, operations, and equipment that are not 
part of the same facility, as defined in this section, shall not be 
aggregated.
    Natural gas means a naturally occurring mixture of hydrocarbon and 
nonhydrocarbon gases found in geologic formations beneath the earth's 
surface. The principal hydrocarbon constituent is methane.
    Natural gas transmission means the pipelines used for the long 
distance transport of natural gas (excluding processing). Specific 
equipment used in natural gas transmission includes the land, mains, 
valves, meters, boosters, regulators, storage vessels, dehydrators, 
compressors, and their driving units and appurtenances, and equipment 
used for transporting gas from a production plant, delivery point of 
purchased gas, gathering system, storage area, or other wholesale source 
of gas to one or more distribution area(s).
    No detectable emissions means no escape of HAP from a device or 
system to the atmosphere as determined by:
    (1) Instrument monitoring results in accordance with the 
requirements of Sec.  63.1282(b); and
    (2) The absence of visible openings or defects in the device or 
system, such as rips, tears, or gaps.
    Operating parameter value means a minimum or maximum value 
established for a control device or process parameter which, if achieved 
by itself or in combination with one or more other operating parameter 
values, indicates that an owner or operator has complied with an 
applicable operating parameter limitation, over the appropriate 
averaging period as specified in Sec.  63.1282 (e) and (f).
    Operating permit means a permit required by 40 CFR part 70 or part 
71.
    Organic monitoring device means an instrument used to indicate the 
concentration level of organic compounds exiting a control device based 
on a detection principle such as infra-red, photoionization, or thermal 
conductivity.
    Primary fuel means the fuel that provides the principal heat input 
(i.e., more than 50 percent) to the device. To be considered primary, 
the fuel must be able to sustain operation without the addition of other 
fuels.

[[Page 226]]

    Process heater means an enclosed device using a controlled flame, 
the primary purpose of which is to transfer heat to a process fluid or 
process material that is not a fluid, or to a heat transfer material for 
use in a process (rather than for steam generation) .
    Safety device means a device that meets both of the following 
conditions: the device is not used for planned or routine venting of 
liquids, gases, or fumes from the unit or equipment on which the device 
is installed; and the device remains in a closed, sealed position at all 
times except when an unplanned event requires that the device open for 
the purpose of preventing physical damage or permanent deformation of 
the unit or equipment on which the device is installed in accordance 
with good engineering and safety practices for handling flammable, 
combustible, explosive, or other hazardous materials. Examples of 
unplanned events which may require a safety device to open include 
failure of an essential equipment component or a sudden power outage.
    Shutdown means for purposes including, but not limited to, periodic 
maintenance, replacement of equipment, or repair, the cessation of 
operation of a glycol dehydration unit, or other affected source under 
this subpart, or equipment required or used solely to comply with this 
subpart.
    Startup means the setting into operation of a glycol dehydration 
unit, or other affected equipment under this subpart, or equipment 
required or used to comply with this subpart. Startup includes initial 
startup and operation solely for the purpose of testing equipment.
    Storage vessel means a tank or other vessel that is designed to 
contain an accumulation of crude oil, condensate, intermediate 
hydrocarbon liquids, produced water, or other liquid, and is constructed 
primarily of non-earthen materials (e.g., wood, concrete, steel, 
plastic) that provide structural support.
    Surface site means any combination of one or more graded pad sites, 
gravel pad sites, foundations, platforms, or the immediate physical 
location upon which equipment is physically affixed.
    Temperature monitoring device means an instrument used to monitor 
temperature and having a minimum accuracy of 2 
percent of the temperature being monitored expressed in [deg]C, or 
2.5 [deg]C, whichever is greater. The temperature 
monitoring device may measure temperature in degrees Fahrenheit or 
degrees Celsius, or both.
    Total organic compounds or TOC, as used in this subpart, means those 
compounds which can be measured according to the procedures of Method 
18, 40 CFR part 60, appendix A.
    Underground storage means the subsurface facilities utilized for 
storing natural gas that has been transferred from its original location 
for the primary purpose of load balancing, which is the process of 
equalizing the receipt and delivery of natural gas. Processes and 
operations that may be located at an underground storage facility 
include, but are not limited to, compression and dehydration.

[64 FR 32648, June 17, 1999, as amended at 66 FR 34555, June 29, 2001]