Pamela F. Faggert ChiefEnvironmental Officer and Vice President-Corporate Compliance Dominion Resources Services, Inc. 5000 Dominion Boulevard, Glen Allen, VA 23060

**Phon~** 804-273-3467 dom.com

By Electronic Mail: oilandgas.whitepapers@epa

.gov June 16, 2014 RE: White Papers on Methane and VOC Emissions in the Oil and Natural Gas Sector Dear Sir or Madam: We appreciate the opportunity to comment on the white papers EPAreleased onApril 15, 2014 regarding emissions and mitigationtechniques for methane and volatile organic compounds (VOCs) in the oil and gas sector. Itis ourunderstanding thatthese papers will be used by EPA, along with the input received from peerreviewers and the public, to determine howto best pursue additional emissionreductions from these sources. The EPA white papers focus on five distinct parts ofthe oil and gas sector; namely, (1) compressors, (2) leaks from natural gas production, processing, transmission and storage, (3) pneumatic devices; (4) liquid unloading processes and (5) emissions from completions and ongoingproduction ofhydraulically fractured oil wells. The white papers include a review of the state ofemissions knowledge in these areas, and identify methods, technologies and potential costs to control methane and VOC emissions. We offer comments onthe approach, in general, and specific comments onthree ofthe papers that are mostrelative to Dominionnatural gas operations, namely the papers oncompressors, pneumatic devices, and leaks from natural gas production, processing, transmission and storage. Dominion Energy, Inc. operates natural gas processing, transmission, storage and distribution assets inthe Appalachian region and the liquefied natural gas (LNG) terminal located in Cove Point, Maryland. These assets are an integral parts ofthe nation's natural gas infrastructure. Twenty-three ofthose facilities report methane (greenhouse gas) emissions under SubpartW. These facilities include eighteentransmission and/or storage compressor stations, two processing facilities, one LNG Import/Export facility, and two local distribution companies. Dominion Transmission, Inc. (DTI) is aNatural Gas STARpartner company and reports results ofselected mitigationpractices underthe program annually to EPA. We appreciate EPA's efforts to better understand methane emission sources and possible mitigationpractices that canbe used to further decrease emissions ofgreenhouse gases. As the use ofnatural gas increases, Dominion is committedto continuing to examine mitigation opportunities andto implementthose that are found to be economicallyprudent andDominionEnergy, Inc.Comments EPA Methane Mitigation Technical White Papers June 16,2014 Page 

### 12 environmentally responsible. We encourage EPA to develop more accurate and current emissions estimates for sources inthe natural gas industry. In addition, we ask that this process fully consider the role ofnatural gas inthe nation's energy future recognizing that natural gas combined cycle combustionunits generally have halfthe 

### C02 emissions as generation from coal-fired units. 1 Therefore, newnatural gas powered generation should be encouraged not only nationally, butinternationally. To date, EPA has relied primarily on two programs to understand methane emissions from the natural gas industry, namely the Natural Gas STARprogram and the Greenhouse Gas Reporting Program (GHGRP). These programs have two separate and distinctpurposes- the Natural Gas STARprogram seeks to identify and document voluntary methane mitigation technologies and practices in specific applications inthe industry, while the GHGRP collects data on methane emissions from the industry as a whole. This distinction is very important in understanding where and how this information is most appropriately used in determining economically prudent and environmentally impactful reduction opportunities. The information available from the Natural Gas STARprogram canhelp answer what technologies and practices may be beneficial over a larger population ofsources, but in some cases further verification is warranted to determine long term performance when compared to alternatives at particular sources. The GHGRP, onthe otherhand, has collected data on methane emissions overthe pastthree years. This datahas been used to identify the major sources ofmethane emissions in the industry and may be used to determine where mitigation technologies could be most beneficial. In some cases, such as pneumatics, leaks at measuring and regulating (M&R) sites for the distribution sector, vapor recovery units at LNG facilities, and pipeline services and mains, emissions are based on "average" emission factors that were developed in the late 1990s and which may not reflect currentpractices. To fully understand where emissions can be mitigated it is necessary to understand not only the average emissions, but the range ofemissionrates over a larger population. Recent studies, referenced below, have indicatedthat a small number ofsources are responsible for the majority ofemissions. While the datafrom the GHGRP can serve to inform mitigationpolicies, the underlying measurement and calculation methodologies need to be considered so thatthe data is used appropriately whether direct measurement, population counts, or survey-specific emission factors. As EPA moves towards a broader methane reduction strategy, including future potential regulation, we ask that EPA continue to work with industry to more fully analyze and understand the informationthat has been developed thus far, to identify gaps in ourunderstanding that must be filled to move forward with a sound scientific basis, and to cooperatively develop and implement a strategy to address those gaps. The White Papers are a reasonable starting point for obtaining more information onthe state of knowledge regarding emission sources and possible mitigation methodologies. However, more targeted research is needed to fully understand the costs and benefits ifthese methodologies are 1U.S. Energy Information Administration, Frequently Asked Questions: How much carbon dioxide (C02) is produced when different fuels are burned? available at http://www.eia.gov/tools/faqs/ faq.cfm?id=73&t=llDominion Energy, Inc.Comments EPA Methane Mitigation Technical White Papers June 16,2014 Page 

### 13
to become part ofany future rulemaking. We encourage EPA to work with the industry and with equipment vendors to validate assumptions, such as costs and applicability ofmitigation techniques which may be limited to a subset ofequipment types. Further, we ask that EPA make full use ofthe data collected under the GHGRP to develop emission factors that are based on current industry performance and that are statistically significant. Compressors The mitigation technologies identified inthe compressor white paper for use with reciprocating compressors are rod packing replacement, and gas recovery using either recovery for compressor fuel or a facility vapor recovery unit (VRU). The technologies identified for centrifugal compressors are the use ofdry seals or the use ofemissions controls (flares or gas recovery) for those systems using wet seals. In EPA'sPetroleum andNatural Gas Systems 2012 Data Summary (pg. 13) the primary source ofprocess emissions from compressors are identified as leaks in rod packing (reciprocating compressors), emissions from wet or dry seals (centrifugal compressors), emissions from blowdown vents, and emissions from isolation valve leakage. The source ofemissions may vary based onthe mode ofoperationthat the compressor is in. A compressor in operating mode may have different emissions from a compressor in a shutdown depressurized mode. Because the emissions are from seal leakage, even compressors ofthe same manufacture canhave different emissions based on the quality ofthe compressor seals. Emissions can be mitigated through rigorous maintenance practices and leak surveys,routing emissions to a flare, or capturing emissions. We agree that compressors ofthe same manufacture can have different emissions based onthe quality ofcompressor seals. Further, it is our experience thatthe use oflow emissions packing (LEP) compressor seal types does notnecessarily result in decreased emissions. In 2010, we started a side-by-side comparison ofa LEP versus conventional packing at four compressor stations. LEP and conventional packing were installed at the same time on two "sister" compressor units at each station. Measurements were taken optimally once a day when the system was pressurized using an orifice meter custom designed specifically to measure packing leaks. These measurements were then recorded by the operator. Measurements are continuing at two ofthe facilities and were discontinued at the othertwo locations due to resource constraints. Measurements are summarized in Table 1 and show emissions in both operating and nonoperating pressurized modes.DominionEnergy, Inc
.Comments EPA Methane Mitigation Technical White Papers June 16, 2014 Page 

### 14

Years Data Station Collected

Station

#4 3 Average Table 1.

Packin

The measurement system used was the best available at the time, but was possibly less than ideal when used to measure a dual-phase gas stream containing oil mist which may have beenpresent when some ofthese measurements were made. The gas stream was also at a lowpressure which further complicated accurate measurement. However, based on the several hundred measurements made over the course ofthe study, we could only conclude that the performance ofthe LEP versus conventional packing does not conclusively showthat LEP provides a superior performance over conventional packing. Taken at face value, the data collected would indicate that there is no consistent difference inperformance. LEP may be useful in some applications, but clearly more research is needed to identify what circumstances indicate the use ofLEP as a reductiontechnology.Dominion Energy, Inc.Comments EPA Methane Mitigation TechnicalWhite Papers June 16, 2014 Page 

### 15 Changing compressor rod packing at a set interval is also discussed as a means ofreducing methane emissions. We supportthis approachprovided the operating company is allowed the flexibility to establish a packing replacement interval that coordinated with regular scheduled maintenance. The use ofcondition-based replacement would require monitoring ofthe packing vent and we are not aware ofa proven monitoring methodology for this purpose, as discussed above, The desired outcome ofa rod packingreplacementprotocol is to prevent methane emissions to the environment, but the frequency ofreplacementmust considerthe blow down emissions that occur each time the packing is replaced. We encourage the development of reliable, cost effective leak detectiontechnologies that would supportthe the use ofconditionbased maintenance practices in the future where packing is monitored and replaced when it starts to fail is preferred over changing packing at a set interval The use ofarobustpredictive maintenance program would allows the operatorto monitor the unit and change packing when it is starting to fail but the operatormust be able to reliably monitorthe rod packing ventto be able to use this approach. The compressor white paper further discusses the use ofdry seal centrifugal compressors and specifically asks ifthe there are situations where new wet seal centrifugal compressors are being installed inthe field. We have not installed wet seal compressors for more than twenty years and do not anticipate a need for doing so. Pneumatics Itis our experience that the use ofhigh

- bleed natural gas driven pneumatic controllers is limited to applications that require very high reliability and lowresponse times, such as emergency shutoffvalves onmain lines that must activate in emergency situations. In remote areas where electric power is not available, low-bleed pneumatics are required. Based onthe emissions expected from pneumatics and in consideration ofthe design requirements to meetperformance criteria for safe operation, further policies and regulatory requirements for pneumatic controllers do not appear to be warranted beyond those already found in the New Source Performance Standards for the Oil and Natural Gas Sector (40 C.F.R. Part 60 Subpart 0000). Leaks One aspect ofleak mitigationprocesses that has become apparent through the results ofrecent studies is thatthe majority ofmethane emissions result from a few leaks. 2 This consistent finding is critical to the development ofcost-effective leak mitigationprocesses. A Directed Inspection and Maintenance (DI&M) programbegins with a baseline survey to identify and quantify leaks. Repairs that are cost-effective to fix are then made to the leaking components. Subsequent surveys are based on data from previous surveys, allowing operators to concentrate onthe components that are most likely to leak and are profitable to repair. Baseline surveys of 2A.R. Brandt, et al., Methane Leaks from North American Natural Gas Systems, Science, vol. 343 (Feb.l4, 2014); David T. Allen, et al.,Measurements ofMethane Emissions at Natural Gas Production Sites in the United States, Proceedings of the National Academy ofSciences ofthe United States ofAmerica (PNAS), vol. 110, 17768-17773 (2013).DominionEnergy, Inc.Comments EPA Methane Mitigation Technical White Papers June 16,2014 Page 

### 16 Natural Gas STARpartners' transmission compressor stations found thatthe majority offugitive methane emissions are from a relatively small number ofleaking components. 3 A prescriptive Leak Detection and Repair (LDAR) program, onthe otherhand, requires a full survey ofall potential leakpoints at a set frequency without regard to leak history or rate. This universal approach along withthe accompanying recordkeeping requirements makes LDAR less cost- and resource-effective. We believe that a betteruse ofresources is to build an inventory of"leakers" that canbe consistently monitored and repaired rather thanto periodically recreate an inventory of"non-leakers". Each company has a unique equipment listthat is reflected inthe age, service, and maintenance history that canbe used to create a DI&Mprogramthat is most effective and efficient for their systems. Further, each company has a unique operating philosophy that is reflected intheir strategic use ofassets. For example, some companies have operated assets that have beeninplace for many decades in the Appalachian basin, but with the recent shale plays in this areathere is a need to operate assets for a few years as wells are developed in an area and then relocate to meet demand in other locations. This shift in asset usage was recognized by EPA when it amendedthe Subpart 0000requirements to allowre-evaluation ofstorage tank emissions at well sites, so that control equipment could be utilized where 

### itis most beneficial. The Leaks White Paper cites the ICF Study4 conclusion that LDARis inexpensive. We suggest that the expense ofimplementation ofa comprehensive LDARprogram has been underestimated and is an unnecessary cost when similar results canbe achieved using a robust DI&M program that is designed specifically for the operation it is intended to benefit. This is particularly true considering unnecessary monitoring in remote locations that have low leak potential. Conclusion In summary, we ask that this process fully consider the role ofnatural gas inthe nation's energy future and encourage EPA to develop more accurate and current emissions estimates for sources inthe natural gas industry that reflect current technologies andpractices. Specific mitigation practices for leak detection and repair should be based on cost-effective DI&Mthat has been shownthrough the Natural Gas STARprogram to be successful in decreasing leaks. The design and use ofpneumatic devices has changed and continues to change as companies comply with the New Source Performance Standards that specify the use oflow-bleed and no-bleed devices. We have shared our experience with LEP for mitigation ofleaks around compressorrod packing and ask that EPA consider alternative practices for compressors, namelythe use ofconditionbased maintenance programs. Much work is currently underway that will inform our understanding ofmethane emissions and potential mitigation practices. As EPA is aware, some ofthe work that has been accomplished to 3 U
.S.Environmental Protection Agency Natural Gas STARPartners, DirectedInspection andMaintenance at Compressor Stations. EPA 430-B-03-008 (October2003). 4 ICF InternationaL. 2014. Economic Analysis ofMethane Emission Reduction Opportunities inthe U.S. Onshore Oil and Natural Gas Industries
. ICF International (Prepared for the Environmental Defense Fund). March 2014.Dominion Energy, Inc.Comments EPA Methane Mitigation Technical White Papers June 16, 2014 Page 

### 17 date, and which forms the basis ofthe technical white papers, is based inpart on work that was conducted some twenty years ago and which may not reflect currentpractice. We applaud EPA's efforts to better understand the portions ofthis workthat are appropriate to consider moving forward and which need to be re-evaluated based onthe more recent GHGRP information. We encourage a coordinated effort to develop flexible and effective mitigation policies that will allow the larger environmental benefits ofnatural gas as a clean and abundant domestic energy source to be realized. As discussed in the recently issued White House Climate ActionPlan: Strategy to Reduce Methane Emissions, the need for a sound understanding of methane emissions from the natural gas industry is critical to ensuringthat the benefits ofnatural gas are attained. We are a partner inthe natural gas transmission and storage study ofthe NGOindustry cooperative research initiative sponsored by the Environmental Defense Fund and support these efforts to close the gaps in ourunderstanding ofmethane emissions and to develop cost-effective emission mitigationpolicies. In closing, we again express our appreciation for the opportunity to comment and trust thatthe actions that EPA will take as a result ofthis evaluation and the comments received will reflect a clear and science-based approach. We hope that the comments provided will be useful in furthering this process. Ifyou have any questions, please call me at 804-273-3467 orRoberta Gellner at 804-464-5961 (roberta
.j
.gellner@dom.com). Sincerely,

PamelaF. Faggert