June13,2014RobertoMoralesU.S.EnvironmentalProtectionAgencyOfficeofAirQualityPlanningandStandardsMailCode:C404-02109T.W.AlexanderDriveResearchTrianglePark,NC27711Re:Williams'ResponseandCommentstoMethaneIVOCEmissionsandMitigationTechniquesinlVe111kenrg)'11I_Pn....ReportforOilandNaturalGasSectorPneumaticDevices,ReviewPanel,April2014U.SEPAOfficeofAirQualityPlanningandStandards{OAQPS)DearMr.Morales:TheWilliamsCompanies,Inc.(Williams)issubmittingthiscorrespondencetotheUnitedStatesEnvironmentalProtectionAgency(EPA)regardingmethaneandvolatileorganiccompoundemissionsandmitigationtechniquesforpneumaticdevicesinEPA's,ReportforOilandNaturalGasSectorPneumaticDevices,ReviewPanel,April2014.InApril2014,EPAsolicitedtechnicalcommentsandadditionalinformationfromreviewersonfivewhitepaperscoveringmethaneandvolatileorganiccompounds(VOCs)emissionsfromcompressors,hydraulically-fracturedwells,leaks,liquidsunloading,andpneumaticdevices.Williams'responseforpneumaticdevicesispresentedinthisletter;aseparateletterhasbeensubmittedtoEPAforcompressors.Williamsreportsgreenhousegas(GHG)emissionsfor60naturalgastransmission,48gathering,16naturalgasprocessing,1petrochemical,and2undergroundstoragefacilitiesacrosstheUnitesStates.These,andothersmallerWilliams'facilitiesthatarecurrentlybelowreportingthresholds,couldbeimpactedbyfutureEPArulemakingonmethaneandVOCreductions.Williamshasdemonstrated,andcontinuestodemonstrate,itscommitmentandcooperationtowardreducingGHGemissionsbyidentifyingandprioritizingGHGsources,implementingGHGmonitoringprograms,andworkingwithindustrygroupssuchasInterstateNaturalGasAssociationofAmerica(INGAA),GasProcessorsAssociation,andtheAmericanPetroleumInstitute(API).WilliamsrecognizestheimportanceofthisissueandsharesEPAandtheAdministration'sintentiontoreducetheseemissions.Inorderforthatefforttoachieveourmutualobjectives,astrong,science-basedapproachmustbeappliedandsufficient1and accurate data must be assembled. Sufficient data does not yet exist and, therefore,

it would
be premature
for EPA to rely on existing data
in any formal rulemaking proceeding.

In order to obtain sufficient and accurate data, Williams

is participating

in current studies
to determine methane emissions from our systems,

is engaged

in roundtable discussions with the Secretary

of Energy and others, and commits

to participating throughout EPA's proceedings

on this issue. Responses

to EPA's charge questions from Williams' subject matter experts
on pneumatic devices are presented below. WILLIAMS' RESPONSE

TO EPA CHARGE QUESTIONS Question

1: 

### Did this paper appropriately characterize

the different studies and data sources that quantify emissions from pneumatic controllers and pneumatic pumps

in the oil and gas sector? Answer: There are additional
and ongoing investigations

and studies based on information learned from industry trade organizations.

The additional information

in these studies

is needed due to the low number and age of the current referenced studies
on pneumatic devices, and the conflicting
and poorly understood data contained

in the current reports. Question

2: 

### Please discuss explanations
for the wide range of emission rates that have been observed

in direct measurement studies of pneumatic controller emissions (e.g.J Allen et ai.J 2013 and Prasino 2013}. Are these differences driven purely
by the design of the monitored controllers

or are there operational characteristicsJ
such as supply pressureJ that play

a crucial role in determining emissions? Answer: While significant differences may be due to differences

in manufacturer design and ongoing equipment maintenance procedures, other factors may also provide significant differences

in monitored emission rates. As mentioned

in the studies and herein, the true nature
of the devices studied (intermittent,

low bleed, etc.) was taken from information provided

by field staff and may not have been properly characterized

for the studies.

In addition, there are wide variations

in the actual conditions these pneumatic devices may be experiencing under field conditions. Differences

in field gas quality, and especially
the pressures that these devices experience,

are significantly different across the country. Also, there may be significant differences

in monitored emissions due to different staff involved, variations

in sampling equipment, monitoring protocols, equipment calibration
and monitoring techniques. Periodic monitoring
and proper maintenance

and cleaning

of pneumatic devices may be useful

in ensuring that these devices have low emissions rates. Question

3: 

### Did this paper capture the full range of technologies available

to reduce emissions from pneumatic controllers and pneumatic pumps
oil and gas facilities?

2Answer: Williams

is currently unaware

of other mitigation techniques. Question

4: 

### Please comment

on the pros and cons of the different emission reduction technologies. Please discuss **efficacy~** 

### cost and feasibility for both new and existing pneumatics. Answer: The White Paper appears

to capture the issues associated with these various techniques. Williams currently
has no experience with zero bleed controllers
due to the nature
of our operations.
Low bleed controllers have been the standard pneumatic device installed

in our operations

in recent years, except where

a high bleed pneumatic controller may be needed due to process

or safety/reliability concerns. We believe low bleed controllers

to be generally reliable and cost-effective.

The use of instrument

air at locations where on-site electric power

is available
has also been the standard, except where

a pneumatic controller may be needed due to process
or safety/reliability concerns. Electric controllers are also being investigated where on-site electric power

is available

in non-critical applications
due to reliability and safety concerns. Question

5: 

### Please comment

on the prevalence

of the different emission control technologies
and the different types of pneumatics

in the field. What particular activities require high bleed pneumatic controllers and how prevalent
are they
in the field? Answer: High bleed pneumatic devices are typically found
at older field locations, and in applications that demand

a very high degree
of reliability such as the inlet of a compressor station
or gas plant where they may be used to control emergency valves
or isolation block valves.

It is important that high bleed devices continue

to be used

in these circumstances,
since low bleed devices cannot provide fast enough actuation response times or sufficient

air to actuate the large block



## I isolation valves. Question

6: 

### What are the barriers

to installing instrument

air systems for converting natural gas-driven pneumatic pumps and pneumatic controllers

to air-driven pumps and controllers? Answer: Typically,
the availability

of on-site electric power

is needed for this type

of conversion. Many compressor stations are in remote locations, away from an electrical power grid, making the conversion to instrument

air impractical

or very expensive.



### 3Question

7: 

### Are there situations where

it may be infeasible

to use air driven pumps and controllers

in place of natural gas-driven pumps and controllers even where

it is feasible

to install an instrument

air system? Answer: As previously discussed,
the use of pneumatic controllers, including high bleed pneumatic controllers, may be warranted where the need for high reliability

of operation,
and other safety and process concerns

is required. Question

8: 

### Did this paper correctly characterize

the limitations

of electric-powered pneumatic controllers and pneumatic pumps? Are these electric devices applicable

to a broader range of the oil and gas sector than this paper suggests? Answer: Williams believes this White Paper has generally characterized

the use of pneumatic controllers
and pumps correctly. These devices, including pumps, are being used
in the field
in greater numbers wherever

a reliable source
of electric power (including solar) can provide for their reliable operation, and where the particular process allows for their use. Question

9: 

### Are there ongoing

or planned studies that will substantially improve the current understanding

of VOC and methane emissions from pneumatic controllers and pneumatic pumps and available techniques
for increased product recovery and emissions reductions? Answer: Yes, additional studies are currently underway, based on information learned from industry trade organizations.

In addition, manufacturers

of these devices are being pressed

to also provide additional data regarding the operation and characterization

of these devices and their associated emissions under varying operating conditions
and pressures. Williams believes that EPA's consideration

of the above response and comments,
and input from others in the natural gas industry, will help the Agency better understand options for cost-effectively reducing methane emissions.
We believe that some data gaps still remain, and that filling these gaps with additional measurement
data

is necessary before EPA develops best practices, voluntary actions, and



## I or regulations regarding methane reductions.



### 4Williams appreciates
the opportunity

to provide comments regarding EPA's Report for Oil and Natural Gas Sector Pneumatic **Devices~** Review **Panel~** April2014. Should you have questions regarding these comments, please contact me at (713) 215-2134

or at glen.jasek@williams.com

. 

# ~ Glen Jase Director

of Environmental Services



### 5