C. Major Comments Concerning Pneumatic Controllers

1. Definition of Affected Facility

Comment: Some commenters request that the EPA consider 

excluding or exempting emergency and/or safety system devices 

(such as a pilot operated pressure relief valve). According to 

one commenter, safety system devices typically do not emit gas 

unless there is an emergency, have a near-zero VOC-level static 

state and, if regulated, could be replaced by substandard, 

cheaper technology of spring operated valves which would create 

much more leakage of gas into the environment. 

With regard to emergency situations, another commenter 

argues that the proposed standards that apply to pneumatic 

controller affected facilities (40 CFR 60.5390(b)) could inhibit 

safe plant operation during an emergency because they require 

that each pneumatic controller located at a natural gas 

processing plant have zero natural gas emissions. According to 

the commenter, a gas-powered controller is a reliable 

alternative for safe plant operation during emergencies, and the 

commenter suggests that the final rule include an exception to 

allow gas plants to use natural gas-driven pneumatic controllers 

for emergency plant shutdown and subsequent startup. 

With regard to high-bleed pneumatic controllers, several 

commenters request that the EPA further explain when the use of 

high-bleed pneumatic controllers is allowed and provide specific 
examples of exemptions. The commenters suggest exemptions that 

address situations such as those where the natural gas includes 

impurities that could increase the likelihood of fouling a lowbleed pneumatic controller, such as paraffin or salts; where 

weather conditions could degrade pneumatic controller 

performance; during emergency conditions; where flow is not 

sufficient for low-bleed pneumatic controllers; where 

electricity is not available; and where engineering judgment 

recommends their use to maintain safety, reliability or 

efficiency. Several commenters request that the EPA provide 

additional information about how to demonstrate that the use of 

high-bleed pneumatic controllers is predicated, as stated in 

proposed 40 CFR 60.5390(a). The commenters suggest that this 

exemption is very vague, will allow for excessive emissions and 

is not enforceable. 

Response: In the final rule, the EPA is changing the 

affected facility to a continuous bleed natural gas driven 

pneumatic controller with a natural gas bleed rate greater than 

6 scfh and which commenced construction on or after August 23, 

2011. The EPA notes that the rule contains functional exemptions 

for use of a controller with a natural gas bleed rate greater 

than 6 scfh. These exemptions include, but are not limited to, 

response time, safety and actuation of valves. These functional 
exemptions to the requirement address the commenters’ concerns 

of safety, emergency and otherwise non-routine situations.

Comment: Several commenters express concerns with the 

proposed rule’s treatment of various types of pneumatic devices 

and controllers. One commenter requests that the EPA clarify in 

40 CFR part 60, subpart OOOO that intermittent bleed pneumatic 

devices are not affected sources. Another commenter asserts that 

continuous low-bleed controllers that replace existing 

continuous low-bleed controllers should not be “affected 

facilities.” According to this commenter, some designed highbleed devices may be isolated from the gas pressure with a valve 

and operated manually on an intermittent basis. The commenter 

wants clarification in the rule that will allow an operator to 

use a high-bleed device if it is operated in a manner that keeps 

its emission levels less than 6 scfh. 

One commenter requests that the EPA clarify in the final 

rule that the distribution segment and self-contained devices 

that release gas to a downstream pipeline instead of to the 

atmosphere are exempt. Another commenter argues that no-bleed 

pneumatic devices have zero emissions and, thus, should not be 

included in the proposed rule.

One commenter discusses the use of solar-powered 

controllers, fuel-cell powered controllers and mechanicallycontrolled devices in remote locations as an alternative to 
natural gas where grid electricity is not available. This 

commenter also recommends that the EPA set a zero emissions 

standard based upon no-bleed devices wherever electricity 

(either from a grid or from field power sources) is available 

within a reasonable distance from the facility and suggests that 

the EPA could establish an exemption to no-bleed devices where 

low-bleed devices are necessary because no-bleed devices cannot 

be feasibly installed.

Another commenter states the definition of “pneumatic 

controller” is unclear and should be revised.

Response: In response to comment, the EPA has clarified in 

the final rule that a pneumatic controller affected facility is 

a continuous bleed natural gas-driven pneumatic controller 

operating at a bleed rate greater than 6 scfh, which would 

exclude intermittent bleed devices, pneumatic devices not 

related to control, and instrument air. The emission limits in 

the final rule would effectively eliminate the use of most 

pneumatic controllers that emit more than 6 scfh for new 

(including replacement) and modified continuous bleed pneumatic 

controllers. Also, to ease the burden on future replacement or 

modification, the final rule requires only that the affected 

facility (i.e., continuous natural gas driven pneumatic 

controllers with a bleed rate above 6 scfh) be tagged as such, 

so that they can be tracked separately from devices below the 
emission limit. The EPA also clarifies that a no-bleed 

controller is not an affected facility in the final rule. The 

EPA also confirms that the rule requirements for pneumatic 

controllers list the industry segments covered by the regulation 

(see 40 CFR 60.5430), which addresses a commenter’s request for 

clarification about distribution segment devices.

Regarding the comments related to solar-powered 

controllers, fuel-cell powered controllers, mechanicallycontrolled devices and no-bleed devices wherever electricity is 

available, we considered these types of devices in the BSER 

analysis, as discussed in the TSD. Any such controller system 

would require a backup system (consisting of at least an 

electrical generator) to operate the controllers when the 

primary system was inoperable. When considering the cost of the 

backup system, these options were not cost effective. 

Comment: Several commenters request an exemption for all 

affected facilities handling gas with less than 10-percent VOC 

content by weight. Some commenters offer suggestions for such 

exemption, such as requiring recordkeeping of the gas VOC 

content in order for a facility to maintain the exemption.

One commenter believes that the EPA should delete the 

pneumatic controller requirements because most of the gas 

emitted is methane, and there is little VOC emission reduction 

benefit. Another commenter suggests limiting applicability to 
pneumatic controllers at natural gas processing plants or 

upstream of processing that exceeds a defined VOC threshold. 

Several commenters opine that pneumatic device definitions 

and applicability should be based on VOC emissions, not natural 

gas as a surrogate. Commenters assert that the 6 scfh highbleed/low-bleed threshold value is unsupported, that natural gas 

VOC content varies widely and that, in most cases, 

unconventionally produced CBM and shale gas have little, if any,

measurable VOC. 

Several commenters also wanted to exclude pneumatic 

controllers driven by a specified percentage of VOC. According 

to the commenters, regulating the use of compressed air or 

“instrument air” or other gas having little or no VOC would 

impose a significant burden on the industry without any added 

benefit. 

Response: The EPA disagrees with the comment that the 

pneumatic controller standards must be based on VOC emissions 

instead of natural gas bleed rate as a surrogate for VOC

emissions rate. Measuring the VOC content of a pneumatic 

controller’s bleed gas adds cost burden to companies and, to the 

EPA’s knowledge, vendors/manufacturers do not report the VOC 

emissions from a pneumatic controller primarily because the VOC 

emissions would depend on the gas composition at the site the 

pneumatic controller is located. 
In the preamble to the proposed rule, the EPA set forth its 

BSER analysis for pneumatic controllers. In the TSD, the EPA has 

provided cost-effectiveness calculations for the proposed 

pneumatic device emission limits. The commenters do not dispute 

the EPA’s analysis. Rather, the commenters ask that the EPA 

establish a VOC threshold. However, the commenters have not 

provided information on how an appropriate threshold can be 

established. One commenter suggests a threshold of 10 percent 

VOC content by weight, but has not provided supporting 

information justifying this threshold. However, for the reasons 

stated in the response to comment immediately below, the EPA has 

decided not to cover in this final rule the pneumatic 

controllers in the transmission and storage segment. With 

respect to those controllers we are not taking final action at 

this time.

Comment: One commenter suggested that the EPA provide a 

phase-in period to allow manufacturers and companies time to 

designate which controllers qualify as low-bleed. This commenter 

further notes that bleed rates are not specified for pneumatic 

controllers or are inconsistently represented without 

distinguishing between the continuous bleed stream and the 

actuation stream rates within the gas consumption 

specifications. 
Response: In the proposed rule, for pneumatic controllers1

in the production segment, the EPA proposed a performance 

standard of a natural gas bleed rate of 6 scfh to reflect the 

use of a low-bleed controller, which we had determined to be the 

BSER for reducing VOC emissions from pneumatic controllers in 

the production segment.2 Owners and operators would demonstrate 

compliance based on information in the manufacturers’ 

specifications for the pneumatic controllers, which we had 

believed would provide either the bleed rate or relevant 

information for such determination. Upon further investigation 

in light of the comments, we conclude that such information is 

not always included in current manufacturers’ specifications. We 

anticipate that manufacturers who currently do not provide the 

relevant information for determining bleed rate would adjust to 

this need and begin testing their products and provide the 

necessary information on the products’ specifications. Based on 

public comments and other available information, the EPA 

believes that an adjustment period is needed, during which 

owners and operators could face increased cost and, in some 

instances, difficulty in obtaining necessary supplies due to the 

 

1 For the reasons stated in section V.C, we have changed the affected facility 

to a continuous bleed natural gas driven pneumatic controller with a natural 

gas bleed rate greater than 6 scfh. This change does not affect the proposed 

BSER analysis and VOC limit, which apply to high bleed pneumatic controllers 

in the final rule. 

2 For reasons explained in section IX.C.2, unrelated to the comment at issue, 

the final rule does not include standards for pneumatic controllers in the

transmission and storage segment.
limited number of currently available controllers with adequate 

documentation for determining bleed rate. However, In light of 

the above, we conclude that a low bleed controller is not the 

BSER for pneumatic controller affected facilities in the 

production segment during this first year. As explained in the 

proposed rule, we are not aware of any add-on controls that are 

or can be used to reduce VOC emissions from gas driven pneumatic 

devices. 76 FR 52760. One commenter broadly suggests that we 

consider flares, combustion devices and vapor recovery but 

provides no supporting information. In light of the above, we 

conclude that there is no BSER for pneumatic controller affected 

sources in the production segment during the “adjustment period” 

mentioned above. 

In determining the length of the adjustment period, the EPA 

evaluated relevant comments and available information, including 

information from promulgation and implementation of subpart W of 

the Greenhouse Gas Reporting rule. Subpart W requires operators 

to conduct a complete inventory and report to EPA the number of 

low and high bleed pneumatic devices, as those terms are defined 

in subpart W, over a three year period (i.e., 1/3 of their 

devices every year over a three year period) starting January 

2011. We believe that efforts are well under way for 

manufacturers to provide necessary information to help 

facilities subject to subpart W determine the pneumatic 
controllers’ bleed rates and comply with the reporting rule 

requirements, 1/3 of which must be completed by September 2012 

and another third by September 2013 and the entire inventory by 

September 2014. In light of the above, we do not believe that 

owners and operators would face the difficulty described above 

beyond the first year after this NSPS becomes effective. After 

this first year of “adjustment period,” we believe owners and 

operators should have no problem securing controllers with 

relevant documentation for determining bleed rate. Therefore, 

beginning the second year, the BSER remains the low bleed 

controllers, as proposed. 

For the reasons stated above, the final rule contains no 

standards for pneumatic controller affected facilities in the 

production segment during the first year after this rule becomes 

effective but thereafter requires that all new and modified 

affected facilities to meet a VOC limit of 6 scfh natural gas 

bleed rate to reflect the use of a low-bleed controller. The 

need for adequate manufacturers’ specifications is not an issue 

for pneumatic controllers at natural gas processing plants. For 

pneumatic controller affected facilities at natural gas 

processing plants, we had proposed a zero VOC emission limit, 

the compliance of which can be demonstrated by the use of a nongas-driven controller system. As noted by commenters, most 

natural gas processing plants already use non-gas-driven 
technology such as instrument air systems for safety and 

operational reasons. While one cannot distinguish gas-driven 

pneumatic controllers of different bleed-rates without 

information from manufacturers, a non-gas-driven controller can 

be easily identified by visual inspection. Therefore, no change 

is made since proposal to the standards for pneumatic controller 

affected facilities at gas processing plants. 

In response to comments that units already in stock at the 

time of proposal cannot be used, the EPA clarifies that 

pneumatic controllers that were already in stock or ordered 

prior to August 23, 2011 are considered existing sources and, 

therefore, their installation is not subject to the pneumatic 

controllers NSPS in this final rule.