Environmental Protection Agency (EPA) Methane White Paper

Oil and Natural Gas Sector Leaks

INGAA Comments

1. Introduction

The Interstate Natural Gas Associ ation of America (INGAA), a trade association of the interstate natural gas pipeline industry, submits these co mments on the EPA’s technical white paper, “Oil and Natural Gas Sector Leaks” (Leaks Pape r). On April 15, 2014, the EPA released five technical white papers discussing potentially si gnificant sources of emissions in the oil and natural gas sector. Specifically, the white pa pers focus on potential emissions and mitigation techniques for methane and volatile organic co mpounds (VOCs). INGAA is submitting separate comments on the three papers (Compressors, Le aks and Pneumatics) that address sources applicable to the interstate natural gas transmission and storage (T&S) sector. These comments address the Leaks Paper.

In the Leaks Paper, EPA summarized its current understanding of VOC and methane emissions from this source category, and its current understanding of available mitigation techniques and the cost, effectiveness, and application of these techniques in the oil and natural gas sector. EPA has requested comment on 13 questions related to the contents and conclusions of the Leaks Paper.

INGAA and its member companies have a long histor y of working collaboratively with a variety of stakeholders on numerous greenhouse gas (GHG) related issues, including methane quantification and mitigation. As such, INGAA welcomes the opportunity to contribute its knowledge of emissions and available contro l technologies. INGA A commends EPA for involving stakeholders and inviting comment on the methane white papers.

Executive Summary

INGAA has three general points in response to EPA’ s white papers. First, there are significant

differences in the methane emission estimates produced by EPA’s Inventory of U.S. Greenhouse Gas Emissions and Sinks (the National Invent ory) and the Subpart W portion of its Greenhouse Gas Reporting Program (GHGRP) 1 . There also are significant ga ps in the information available. EPA needs to develop a systematic program to re concile these differences and fill the gaps in order to support further di scussion on methane reductions . Second, INGAA recommends additional discussion and analysis of the implicat ions, including costs, of potential mitigation methods. Finally, EPA should recognize that new information will be available soon to supplement this discussion.

1 See http://www.epa.gov/ghgreporting/ and http://www.epa.gov/ghgreporting/ reporters/subpart/w.html ( Starting with the 2011 calendar year for Subpar t W, the GHGRP requires pipeline companies to submit annual reports of GHG emissions for subject facilities. Pipelines must submit 2014 emission information for the fourth annual report by March 31, 2015).INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 2 of 17 In response to the Leaks Paper specifi cally, INGAA offers the following comments:

1. EPA should support directed inspection a nd maintenance (DI&M) as a mitigation strategy. It is one of the most efficient and cost effective mitig ation strategies.

2. INGAA recommends EPA review of the Subpa rt W data to properly understand leak frequency and distribution. A growing body of work supports the premise that a few larger leaks contribute to the vast majority of emissions. 2

3. INGAA disagrees that all leaks ar e cost-effective to repair. Many factors influence a leak repair decision, including, but not limited to, em ission rates, reliability, material and labor costs, and schedule constraints.

4. Available technologies, including optical gas imaging (i.e., infrared (IR) camera) and EPA Method 21, are adequate for detecting l eaks. EPA should remove ambient/mobile remote monitoring as a leak detection technology. It does not identify a sp ecific leak source and, therefore, cannot be used for that purpose.

5. Finally, EPA should acknowledge that one of the benefits of a pipeline safety integrity management program is a reduction in emissions.

INGAA welcomes the opportunity to contribute to this discussion.

Overview of INGAA Responses

INGAA has attempted to answer each question to th e best of its ability. Due to time and other limitations, however, INGAA has not answered all questions fully. For some questions, INGAA could not respond completely because this woul d require a significant long-term effort (e.g., a research program) that includes all stakeholde rs. For example, quest ions regarding technology prevalence, cost implications and technical feasibility impact s would entail an integrated research effort to provide a quality, validated and vetted answ er. In most cases, however, INGAA has provided a thorough response with the in formation available while noting the gaps in existing data. Whenever possible, INGAA offe rs specific examples of field conditions and industry experience. Appendix A provides a quic k reference to EPA’s questions on leaks and INGAA’s response.

2. Establish an Open Process that Involves A ll Stakeholders to Further Examine Methane

Reduction Issues

Other than the Natural Gas STAR program, EPA has focused its oil and gas industry GHG efforts primarily on quantifying or estimating me thane emissions. EPA must consider a number of issues, including economic, operational and e nvironmental issues as it moves toward a broader methane strategy.

INGAA envisions a process that is transparent and inclus ive of industry and other stakeholders to examine issues and potential strategies. This ha s proven effective at othe r federal agencies and for other EPA regulations. For example, EPA c ould host technical confer ences similar to those

2 This is often referred to as the “80/ 20 rule” or “90/10 rule” (e.g., 90 percent or more of emissions are due to 10 percent or fewer of the leaks).INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 3 of 17 convened by the Federal Energy Re gulatory Commission (FERC) to examine critical issues prior to initiating a rulemaking. 3

This process would provide an efficient a nd effective means to advance the current understanding of methane emissions and how to de sign effective programs. As an example, the EPA GHGRP is intended to develop improved G HG inventories and to inform policy decisions. 4
Subpart W of the GHGRP addresses T&S segment emissions from vents and equipment leaks, and companies have submitted three years of data to date. Data is publicly available for the 2011 and 2012 reporting years, 5 and indicate signifi cant differences between Subpart W reporting and the U.S. National Inventory 6 for T&S sources. These differences are due in part to differences in scope but also other reasons. It is very important that these differences are understood and that a single accurate inventory is in place before EPA or industry can develop and implement effective and efficient mitigation strategies. These pr oposed technical conferences or workshops can provide EPA and industry the platform to discuss these important issues so that EPA’s future methane reduction policies reflect all relevant analysis.

3. Sources of Information on Emissions and Reduction Opportunities 7

EPA has requested comment on whether the Le aks Paper appropriately characterizes the

different studies and data sources . INGAA agrees that it is im portant to understand the sources of methane emissions, how those emissions are measured and reported, what reduction opportunities exist (and what is th e cost associated with these opportunities). While the Leaks Paper provides a summary of several sources of in formation, the paper does not reflect the full

breadth of valuable information available to EPA on the topic. Further, while the studies have been summarized, they are neither compared nor c ontrasted with each other or with other sources

of similar information. It would have been valu able for EPA to provide a tabular summary that presents the primary results from each study in common engineering units in order to identify data gaps and inconsistencies. While it may not have been the intent of the Leaks Paper to compare or contrast information, such an exercise is necessary to determine if a particular study appropriately characterizes the data available. Further, a comparison of the studies would help identify conflicts and data gaps in the information.

3 FERC typically holds public technical conferences to gath er information on important policy issues and to hear potentially competing positions in advance of issuing significant rulemakings. For example, in 2012-2013, FERC

held a series of technical conferences to explore issues surrounding the incr eased use of natural gas for electric power generation and issues that may impede coordination between the gas and electric industries. After considering discussions raised by inte rested stakeholders at the 2012-2013 technical conferences, and subsequent public comments, the FERC initiated two rulemakings that pro pose to address concerns raised by participants at the

technical conferences. Technical confer ences provide the benefit of educating the regulator and other stakeholders on a particular issue and facilitating a structured dialogue where stakeholders can debate the effectiveness or need for prospective action prior to the issuance in a propos ed rulemaking. Often techni cal conferences can reveal stakeholder support for certain initiatives, identify potential flaws in certain proposals, and identify alternative ways to address the regulator’s or stakeholders’ concerns.

4 See 40 C.F.R. Part 98 (2014).

5 EPA publishes GHGRP reporting results through its data publication tool, Facility Level Information on Greenhouse gases Tool (FLIGHT); see http://ghgdata.epa.gov/ghgp/main.do

6 Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2012 , EPA 430-R-14-003 (April 2014). This report presents the U.S. national GHG inventory from 1990-2012 for anthropogenic sources (i.e., associated with human activity) and is referred to as the “National Inventory” in these comments. The report is updated annually.

7 This section generally responds to Leak Paper questions 1 and 2 (emissions studies and data sources).INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 4 of 17 Due to the limited comment period, I NGAA did not have time to deve lop a definitive analysis of

the various studies listed or a list of key studies that were not included. However, more detailed discussion below provides examples of data gaps or differences in the primary tools that are being used to inform the process (e.g., differe nces between Subpart W reporting and the National Inventory).

In general, INGAA views the Leaks Paper as a summary of some information but not the full range of studies and data sources currently avai lable. EPA’s characterization that the studies presented in the paper are pivotal suggests that EPA considers them key to understanding these issues. INGAA would caution EPA against placi ng excessive weight on this limited information since other studies, not referenced in the Leaks Paper, may be based on the same or similar data

sets but reach diffe rent conclusions.

INGAA also urges EPA to elaborate on how it ar rived at its cost analysis for mitigation measures. Cost estimates are sensitive to assump tions and inherent data inconsistencies. Costs vary over time and with locat ion and chosen technology. As presented by EPA, the 2014 study by ICF, Economic Analysis of Methane Emission Re duction Opportunities in the U.S. Onshore

Oil and Natural Gas Industries , (ICF paper) 8 appears to be the primary source of information on evaluating cost-effective emissions reduction opport unities. However, the ICF paper has several limitations such as only including emissions mitiga tion options for a subset of emission sources, only addressing one mitigation technology or wo rk practice for these select sources (i.e., alternatives are not addressed) , and generally not a ddressing uncertainties or presenting ranges associated with emission mitigation costs and performance. Further, several other sources of

similar information have not been referenced. In fact, cost-effectiveness has been examined by a number of organizations such as the Inte rnational Petroleum Industry Environmental Conservation Association (IPIECA) 9 and the Intergovernmental Panel on Climate Change (IPCC). 10 Cost effectiveness has also been a topic during the United Nations Framework Convention on Climate Change (UNFCCC) events. Given the significance of understanding the

costs associated with various methane reduction technologies in crafting a comprehensive costeffective reduction strategy, the L eaks paper should expand the disc ussion to describe more fully the body of available information, including key pa rameters and assumptions that impact cost analyses. As an example, the differences betw een Subpart W data and th e National Inventory for

T&S sources affect the calcula tion for potential achiev able reductions and thus have economic analysis implications.

New sources of information soon will become av ailable that will sign ificantly add to the understanding of methane emissions and reduction opportunities in th e T&S sector. Specifically, the Pipeline Research Council International (PRCI) 11 is completing a report summarizing GHG emission reduction technologies and work practices applicab le to natural gas pipeline compressor stations. The PRCI work will id entify existing and commercially available GHG emission reduction technologies and work practices for pipeline compressor stations, as well as

8 Economic Analysis of Methane Emission Reduction Opportunities in the U.S. Onshore Oil and Natural Gas Industries, ICF International, 2014.

9 Oil and Natural Gas Industry Guidelines for Greenhouse Gas Reduction Projects, March 2007

10 Climate Change 2007, the Fourth A ssessment Report (AR4) of the United Nations Intergovernmental Panel on Climate Change (IPCC).

11 The Pipeline Research Council International (PRCI) is th e global collaborative research development organization of, by, and for the energy pipeline industry.INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 5 of 17 identify technologies in development. The repo rt will evaluate technica l and economic viability of existing and developmental GHG emission reduc tion technologies and work practices. While this report has yet to be released, PRCI has permitted INGAA to acknowledge the draft document for the purposes of our comments. More detail on leak emissions reduction technologies and costs is pr ovided in comments below.

4. National Estimates of Metha ne Emissions and Methane Emission Factors, Activity Data, and Calculation Methodologies 12

EPA has asked for comment on the national es timates of methane emissions and methane emission factors, activity data, and calculation methodologies. While there are several sources of

information on methane emissions from the natu ral gas system, the two primary sources of GHG emission data are the National Inventory and the EPA GHGRP. The EPA compiles both a topdown estimate of GHG emissions (i.e., National Inventor y activity data uses data such as facility count and miles of pipe to estimate emissi ons) and detailed bottom-up reporting (GHGRP). Using other common vernacular, the National Invent ory is commensurate with a Tier 1 or Tier 2 estimate (i.e., using activity data at the facility or large unit level), whil e Subpart W of the GHGRP uses Tier 3 (more granular source or component level activity data) or Tier 4 (detailed source level data or direct measurement) estimat es. These two reports use different methods for estimating methane releases and do not include all of the same sources of releases. Accordingly, there currently is no single compilation that comprehensively and accurately addresses all sources of methane released by the T&S sector.

While the National Inventory and the GHGRP pr oduce consistent estimated emissions from some sources (e.g., the natural gas production segmen t), there are significant differences for the other segments of the natural gas system. There likely are multiple reasons for the disparity, including differences in the methodologies used in the two programs, an d the specific sources being measured and included for reporting. Fo r example, EPA updated key National Inventory estimates for the production segment based on more recent data, including S ubpart W data. In contrast, EPA has not yet updated its key estimate s for the T&S segment, and it does not appear that EPA has compiled or analyzed results base d on thousands of measurements for T&S sources completed in response the GHGRP reporting require ments. INGAA suggests that the approach used for production can also be used to improve the estimates for the T&S sector and to serve as a more accurate basis for determining costs and mitigation opportunities. Work to reconcile these estimates remains an area of needed analysis before drawing any definitive conclusions

about the total level of methane emissions from natural gas pipelines or definitively addressing related questions about mitigation and costs.

The need for more current data and analysis on methane emission levels is highlighted by the

fact that most T&S emission factors used fo r estimating methane emissions are based on a limited set of data that is approximately two deca des old. The emission factors that are used to

calculate methane emissions for both the Natio nal Inventory Report and for some Subpart W sources, have typically been in place since the 1990s and need to be updated. For T&S, the National Inventory (and other pub lished papers and studies) prim arily rely on emission factors

12 This section generally responds to Leaks Paper questions 1 and 2 (emissions studies and data sources), 3 and 4 (emission reductions & leak detection), 5 (impact of facility attributes on emissions), and 6 and 7 (leak detection technologies and efficacy).INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 6 of 17 derived from an EPA – Gas Re search Institute (GRI) study 13 that was completed in the early 1990s and published in 1996. These factors may not accurately reflect na tural gas transmission methane emissions because operatin g practices, as well as the effi ciency of operating equipment, have improved over the past 20 years. INGAA urge s EPA to initiate a program to use the T&S data from 2011, 2012 and 2013 GHGRP reporting to support development of improved emission factors and improved emission es timates for the T&S segments.

The GHGRP also has some limitations, includ ing reliance on dated emission factors and

exclusion of smaller facilities a nd smaller sources at s ubject facilities. Subpart W also does not require reporting of known sources, such as rod packing emissions in “not operatingpressurized” (i.e., standby) mode, and centrif ugal compressor emissions from dry seals. However, analysis of the reported data shoul d significantly improve the understanding of methane emissions from the T&S sector, especi ally where measurement is required. Future improvements in estimates of aggregated methan e emissions, along with use of Subpart W direct measurements to update emission factors, can le ad to more accurate estimates overall. INGAA asks that EPA work with the industry to deve lop emission factors for the sources with new

measurement data available.

Emissions Studies – Leaks Emission Factors, Activity Data and Emission Estimates 14

As noted above, while the emission studies liste d in the Leaks Paper provide a sampling of available information, other valuable sources are available. For example, the Leaks Paper lists two Clearstone Engineering Reports from 2002 an d 2006 that are from a collaborative project that investigated emissions and the effectiveness of DI&M at processing a nd gathering facilities. These projects were subsequent to the original EPA-GRI study, and there were additional papers published in the late 1990s and early 2000s that discussed simila r projects at transmission and storage facilities. This work in cluded facilities in both the U.S. and Canada . In addition, there are reports available that EPA has used for ot her purposes, such as de velopment of equipment

leak emission factors used for T&S sources in Subpart W of the GHGRP. Thus, the listed sources represent a sample but not an all-incl usive list of available studies and data. For transmission, Table 2-4 presents emissions from the EPA-GRI study. We point out that this Table does not reflect the data provided in the narr ative and has internal inconsistencies that need to be corrected. The presentation of data conf idence intervals are in this table (and selected others) is very helpful and an important consid eration. However, confidence intervals are not consistently presented and needs to be consiste ntly used to provide a rudimentary understanding

of the relative accuracies and uncertainties for the various studies. Emission estimate uncertainties are an important c onsideration but methods can vary from report to report. Thus, unless each listed report is reviewed in deta il, it is not possible to understand accuracy and uncertainty for the various studies, so meaningf ul comment on study effica cy cannot be offered.

13 Methane Emissions from the Natural Gas Industry, EPA/GRI report (June 1996) at: http://www.epa.gov/gasstar/tools/related.html ; This 15-volume compendium of reports is from an EPA/GRI study published in 1996 that remains a seminal reference on methane releases from natural gas systems. These reports and related data are referred to as the “EPA-GRI Study” in this paper.

14 In addition to text above, this section generally respond s to Leaks Paper questions 1 and 2 (on emissions), 3 and 4 (emission reductions and leak detection), 5 (impact of f acility attributes on emissions) and 6 (leak detection technologies).INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 7 of 17 A more comprehensive list of reports and leak emissions-relate d documents could be compiled, but a higher-priority endeavor might involve a better characterization of the strengths and weaknesses of available documents, identifying data or information gaps and defining a programmatic approach for resolving discrepanc ies and addressing data gaps differences. INGAA cannot now provide a comprehensive re sponse because there was limited time to respond to the white papers. In addition, INGAA believes there is a general need to develop a systematic approach for compiling and analyz ing information, understanding and reconciling differences in available information, identify ing data gaps, and developing an agreed up inventory. There are also important issues re garding the breadth of each listed study. For example, some studies present emissions data or estimates (where emissions data may be from other projects) and then add an analysis on mitigat ion or costs. Thus, not all listed studies are original work regarding emission estimates, and there may be issues with assumptions regarding mitigation or costs. Also, some of the listed studies are focused on production or other upstream operations and not transmission or storage. 15

In general, the studies presented use co mmon and accepted methods for estimating leak emissions. Leaks are a more complex and complic ated emissions source to understand, but have a relatively long history of “accepted” methods. EP A’s focus should be on studies that provide original data where leaks are not only detected but also measured , because this provides a more complete understanding of leaks. Other emission f actor-based data to estimate leak rate can also be useful but provide less insight. For exampl e, Subpart W of the GHGRP requires leak surveys for transmission, storage, and gas processing. The surveys identify th e number of leaks by component type (e.g., connector, open-ended line , etc.) and then use a component-specific

“leaker emission factor” to estimate emissions. With three years of Subpart W GHGRP reports submitted to date, many leak surveys have been completed and information on leak frequency is available within the Subpart W database. While that data can be insightful as to the prevalence of leaks, it does not provide new information on leak rates because emission factors are used for

the emission calculation.

At this time, natural gas industry stakeholde rs are compiling information from Subpart W reporting for T&S sources, but have not completed analysis of the data. The compressor-related measurements required for Subpart W measure l eaks in some cases. Several source types are measured in defined compressor operating modes in the compressor measurement program. The sources includes vented emissions (e.g., from reciprocating compressor rod packing). As discussed in INGAA comments on the Compressor Pape r, this also includes sources that are considered “leaks” in these white papers, incl uding reciprocating compressor isolation valve leakage in shutdown mode, reciprocating co mpressor blowdown valve leakage in standbypressurized mode and operating mode, centrif ugal compressor isolation valve leakage in shutdown mode, and centrifugal compressor blowdow n valve leakage in operating mode. EPA’s methane papers address leaks within the Leaks Paper and compressor venting in the Compressor Paper, but there is some overlap ping and potentially conflicting c ontent. For example, on page 3 of the Leaks Paper the reference to compressor seal s as a potential leak sour ce is not clear as it could be interpreted to mean reciprocating compressor rod pack ing, which is addressed in the Compressor Paper. As discussed in the Comp ressor Paper, compressor emission factors are sometimes a composite that includes leaks and ve nted emissions. For example, reciprocating

15 INGAA is not familiar with several of these listed studies and does not pl an to review documents that are not

related to the T&S sector.INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 8 of 17 compressor emission factors from the EPA/GR I study include both rod packing emissions (covered in the Compressor Paper) and leaks fr om isolation and blowdown valves (covered in the Leaks Paper). The Compressor Paper explains complications and errors that can result when using such emission factors to assess baseli ne emissions and potenti al reductions.

Although not readily apparent when reviewing Su bpart W reports, direct measurement data are available for compressor isolation valves and blowdown valves, because measurement of leaks from these compressor valves are required for transmission, storage, and gas processing facilities. A project being c onducted by the Pipeline Research Council Internati onal (PRCI) is compiling and analyzing this data. At this time , detailed analysis has not been completed, but 2011 and 2012 reported data show that over 4,000 leak rate measur ements from isolation and

blowdown valves have been completed at T&S facilities. These measurements are separate from rod packing venting and wet seal degassing vent emissions measurement that are the province of the Compressor Paper. It is imperative that th is measurement data be compiled, analyzed, and understood, so that Subpart W results fulf ill the GHGRP objective of providing improved information to inform policy decisions. Thr ough the PRCI project and related INGAA activities, the gas industry will have new and significant additional data to provide to EPA regarding

methane emissions from the T&S sector. Natu ral gas transmission stakeholders welcome the opportunity to work with EPA on analyz ing and understanding these data.

Subpart W and National Inventory Em ission Estimates and Discrepancies

As discussed in INGAA comments on the Compre ssor Paper, the groupin g of compressor-related

emissions can cause confusion. Different studi es and emission factors may treat compressorvented emissions (e.g., from rod packing) and le ak-related emissions from compressor isolation valves and blowdown vent valves differently. For the purposes of S ubpart W reporting, leaks from the isolation valves and blowdown valves (i n the associated operating modes) are measured and reported as compressor emissions, which al so included rod packi ng (for reciprocating compressors) and degassing vent emissions (for centrifugal compressors). Compressor emission factors from the EPA-GRI study, conducted in the 1990s, integrate these emission sources into a composite emission factor that considers the em ission source and time in the related operating mode. Emission factors from the EPA-GRI study are used for National Inventory estimates for the T&S segments. Separately within Subpart W, (other) emissions from equipment leaks are reported, which addresses components, including some compressor related components such as fuel lines that are not speci fically addressed by Subpart W direct measurement.

Further, there are disparities in the Subpart W reported results for compressors, with a significant difference for centrifugal compressors. At this time, it is not clear how the different sources (i.e., vents versus valve leaks) contribut e to the disparities. However, it is important to understand the

data and reconcile differences in the historic al estimate from the National Inventory and estimates based on recent Subpart W measurements . To summarize the differences explained in more detail in comments on the Compressor Paper, when Subpart W results are adjusted (scaled up) to use the same activity data as the Na tional Inventory: (1) re ciprocating compressor

emissions are over 50 percent higher in the National Inventory than emissions based on Subpart W data; and (2) centrifugal compressor emissions are 20 times higher in the National Inventory than emissions based on Subpart W data.INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 9 of 17 Subpart W reports “equipment leaks” based on a leak survey and “leaker” emission factors (separate from the compressor valv e leakage discussed above) and th at data can be scaled up and compared with the National Inventory, which us es facility count as the activity data for estimating leak emissions from compressor stati ons. Based on an initial analysis, Subpart W data has been compiled from 315 transmission faci lities that completed leak surveys in 2011 (i.e., this is about 1/5 to 1/6 of the total T&S facilities in the U.S.). A direct comparison

indicates that the equipment leak estimate from the Nati onal Inventory is ov er 14 times higher than Subpart W reported emissions. When the Subpart W data is scaled up based on average emissions per facility and using th e National Inventory facility count, the National Inventory estimate is over 2.5 times higher than an estimate based on Subpart W data.

As noted, data compilation and review are ongoing, and additional insight may be gained that can be shared with EPA. At this time, the reason for the discrepancies is not clear. It is also not clear how EPA plans to use this Subpart W data to understand emissions and assess whether the national inventory estimate should be revised. INGAA members and other industry operators are expending considerable resources to complete co mpressor measurements of vented emission and valve leakage, as well as annual facility leak surveys. Thousa nds of measurements and hundreds of leak surveys have been completed to da te and ongoing annual measurement is currently required. It is imperative that this significant dataset be used to improve the understanding of emissions from T&S facilities and inform polic y decisions. If not, the GHGRP is not fulfilling its objective.

INGAA recommends that EPA develop a comprehensiv e, systematic plan to compile, review and analyze this data. GHGRP results should be the building block of future emission estimates. These data need to be understood, and differenc es with other data or studies need to be

reconciled. Until the emission estimates are mo re clearly understood, it is not possible to accurately assess emissions reductions or costs associated with mitigation.

Finally, INGAA believes that careful review and understanding of new data from Subpart W is important to advance the unders tanding of leak frequency an d distribution, which have implications for emissions and appropriate m itigation strategies. A growing body of work supports the premise that a few larger leaks contri bute the vast majority of emissions. This is

often referred to as the 80/20 rule or 90/10 rule (e.g., 90 percent or more of emissions are due to 10percent or fewer of the leaks). Many studies support th is assertion (e.g., the original EPA-GRI study, the EPA-sponsored Clearstone Studies listed in Table 2-1). A clear understanding of this phenomenon is needed so that appropriate leak mitigation strategies can be defined. Mitigation

is discussed further below.

Emissions Estimates and Leak Detection 16

Leak Paper questions 3 and 4 inquire about emi ssions estimates and asso ciated leak detection

methods. Emissions estimates are discussed abov e. Regarding leak detection techniques and methods, the Leak Paper adequately discusses th e suite of technologies and methods that are available. This includes newer technology (e.g., optical gas imaging – i.e., the IR camera) and longstanding methods – e.g., Method 21 which incl udes methods that range from soap bubbles to

16 See Leaks Paper questions 3 and 4 (emission reductions and leak detection) and 6 (leak detection technologies).INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 10 of 17 analyzers (“sniffers”) that measure hydrocarbons. The technologies and methods identified are established and adequate for leak detection, and are generally applic able across facility types.

However, the Leak Paper also includes “ambi ent/mobile monitoring” as a leak detection technology. INGAA understands that mobile monito ring has been used in recent studies to identify atmospheric methane and estimate the fl ux rate (i.e., emissions) attributable to an upwind source. While this method/technology may serve a purpose for assessing total emissions from a facility or upwind source, it should not be considered a “leak dete ction” technique, which requires the ability to pinpoint sp ecific leaks coming from individual points within a T&S facility with hundreds or even thousands of components spr ead across several acres. As discussed below in the mitigation section, it is important for the technique to identify the specific source of the leak – i.e., the leaking component – such as Method 21 or an IR camera. Ambient/mobile monitoring does not identify the leak source for a T&S facility and, therefore, should not be identified as a leak detection technology.

Question 4 also inquires about ongoing or pla nned studies. INGAA st rongly recommends the design and implementation of a systematic, comp rehensive study to assess Subpart W data and other data to improve the current understanding of emissions. As noted, PRCI is compiling and analyzing Subpart W data from transmission co mpanies (i.e., PRCI a nd INGAA members) and that information will aid in the understanding of methane leaks and mitigation practices. Several transmission companies are also pa rticipating in an emission study with the Environmental Defense Fund (EDF). The EDF study includes onsite direct measurement and

mobile tracer flux measurements of T&S facilities, and results should be available later this year. INGAA suggests that a collective effort betw een EPA and industry is needed to understand Subpart W data, other existing data, and these ne w results so that more definitive conclusions

can be reached on leak emissions from T&S facilities.

Factors Affecting Emissions from Leaks

Question 5 asks about facility ty pes or other attributes that ma y result in higher leak emission

rates. INGAA believes that a st udy would be required to answer this question. INGAA agrees that the factors listed by EPA are logical parameters to incl ude in a study design, such as equipment type and count, age, maintenance hi story, and gas quality (e.g., sour versus sweet gas), since they could impact leak profiles.

5. Leak Detection Technology 17

The discussion above reviews leak detection technology – Method 21 and IR cameras – as it relates to identifying and estimating emissions . The Leaks Paper captures the methods and technology commonly used for loca ting leaks, and these have a long history associated with VOC emissions. In recent years, the IR camera has been added as a leak de tection tool, and it is widely used for the annual surveys required by Subpart W of the GHGRP.

17 This section responds to Leaks Paper questions 3 and 4 (e mission reductions & leak detec tion), 5 (impact of facility attributes on emissions), 6 and 7 (leak detection technologies and efficacy), 8 (p revalence), 10 (mobile monitoring and optical imaging), and 13 (technology innovation).INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 11 of 17 In general, technologies should be applicable at any type of facility, but some techniques may have greater utility at some facility types. For example, an IR camera facilitates leak screening

of elevated and inaccessible vents that ar e common at T&S compressor stations.

INGAA understands that ambient/mobile monitoring is being used in some studies, and some INGAA members are collaborating with EDF on a st udy that uses tracer flux measurement with an instrumented van. However, that technology should not be considered for leak detection,

because for leak detection to be useful it must pinpoint the exact source of the leak. Mobile monitoring cannot provide that functionality.

It is important to note that th ese technologies and methods are a ssociated with finding leaks. Mitigation approaches discussed below include DI&M, which includes measuring leak rates

when a leak is found. While leak detection technology is relatively robust, leak rate measurement approaches such as the high volum e sampler and calibrated bag methods are more complex and time consuming. Advances in leak measurement technologies are desirable, such as advancing the IR camera to provide leak quantification or l eak rate approximation and binning (e.g., small leak, larger leak worth further scrutiny). At this time , INGAA is not aware of studies

or research that would deve lop or improve technology for leak rate measurement.

In question 10, EPA requests comment on using am bient/mobile monitoring in conjunction with IR camera technology for leak detection. INGAA re iterates that ambient/mobile monitoring for

leak detection at T&S facilities is inappropriate and unnecessary fo r this applicati on. The use of

an IR camera is robust and accura te enough to identify leaks quickly and efficiently without the need of supplemental ambient/mobile monitoring equipment. Pairing with mobile monitoring does not provide useful additional leak informa tion beyond what the IR camera provides, and it actually may reduce the effectiveness of a leak de tection survey due to its additional resource and time requirements. It would also add tec hnology and support labor costs. As discussed below, the principles for implementing leak mitigation are fairly well understood, and mobile monitoring technology is neither needed nor effective for T&S facilities.

Finally, question 8 requests feedback on the pr evalence of leak dete ction technologies and question 7 inquires about costs and efficacy. INGAA is aware that multiple methods are often used for a leak survey depending on the source – e.g., Method 21 to sc reen leaks, acoustic methods to detect through-valve leakage, IR camera for elevated components. However, INGAA is not aware of the prevalence or preferen tial use of certain techniques over others. An answer to this question cannot be provided w ithout conducting a survey to understand operator practices. There may be reasons to use different technologies within a single survey, depending upon the situation. For example, an IR camera may facilitate quicker leak screening but can also be limited by weather conditions and other factors. The equipment cost generally is much higher than other methodologies availabl e. Method 21 may be preferred in some cases to assess the leak relative to a threshold (e.g., 10,000 ppmv). A ll of the standard methods are viable and used in practice, and factors that may affect use for a particular site or survey are best left to the specific company to determine the most effectiv e tools to identify leaks for each of their

facilities.

INGAA takes issue with some information included in the Leaks Paper, but due to the short comment deadline cannot provide a detailed critiq ue of all of areas of disagreement in these comments. For example, the paper notes that an IR Camera can monitor nearly two thousandINGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 12 of 17 pieces of equipment per hour at a refiner (or over 30 per minute). That is likely an over-estimate

for most facilities a nd technology users.

6. Mitigation Techniques and Costs 18

The cost of leak mitigation techniques vary and are generally based on the leak definition and the leak repair decision. For example, a Method 21 threshold (e.g., 10,000 ppmv screening value) is one basis for defining a leak. Conventional leak detection and repair (LDAR) programs that are in place for VOC emissions genera lly include such a definition. If above the threshold, repair is required but qualifiers need to be considered, such as issues associated with elevated components, delay of repair criteria, cost and availability of replacement components, additional gas venting that would occur when the component (s) are replaced, etc. Another approach that differs from LDAR is DI&M, which was used by so me voluntary participants in the Natural Gas STAR program and is well documented in EPA literature 19 and other public domain

documents. 20

For compressor stations, INGAA believes that DI&M considers the key qualifiers and provides the flexibility to identify and address the highest priority leaks that warrant repair. DI&M survey costs are higher than conventional LDAR because leak rates must be measured using a high volume sampler, calibrated bag, flow meter or other appropriate method. The Natural Gas STAR Lessons Learned document provides ad ditional detail on DI&M, and INGAA welcomes the opportunity to discuss DI&M further with EPA. The premise of DI&M is that typically, the largest leaks occur at just a few sources and it is not always economical to repair every leak. INGAA agrees because many factors can affect repair costs. Papers that espouse the theory that it is economical to repair all l eaks were not scrutinized, but perf unctory review indicates that questionable or simplistic assumptions were use d, such as a single or limited number of costs defined for repair. Repairing all leaks is not alwa ys prudent since the cost of the repair may far exceed the benefit of eliminating a small leak.

Many factors can affect leak repair costs, which is a reason that INGAA supports DI&M for compressor stations rather than LDAR programs based on the premise that any leak should be repaired. Factors affecting leak repair costs include:

• Component type (e.g., valve, pum p, rod packing flange, etc.);

• Component location with the faci lity (e.g., access, elevation);

• The ability to repair and action required (e.g., tighten a connection, partial disassembly of simple component to replace a gasket, facility shutdown and major equipment disassembly) or the need for replacement;

• Material needs and purchase and delivery times or availability of spare parts;

• Additional support or material costs;

• Facility operational constraints (i.e., lost opera tional time due to the need to shut down or isolate the component);

18 This section responds to Leaks Paper questions 9, 11 and 12 (leak mitigation and costs).

19 Directed Inspection and Maintenance at Compressor Stations, Lessons Learned from EPA Natural Gas STAR Partners, EPA430-B-03-008, see: http://epa.gov/gasstar/documents/ll_dimcompstat.pdf (October 2003).

20 For example, see the two Clearstone reports, which were EPA sponsored studies, in Table 2-1 of the Leaks Paper.INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 13 of 17 • Lost product (e.g., need to blow down equipment for access);

• Standard labor time required to repair the leak;

• Engineering design support for more complex replacements requiring piping modifications or similar actions;

• Specialized labor or technical expertis e needed for repair or replacement; and

• Impacts to upstream or downstream operations and customers.

A case-by-case evaluation is needed to better understand the cost imp lications of a repair decision. Some repairs can be made easily and quickly, while others may take considerable planning, timing and scheduling prior to impl ementation. DI&M provides a logical thought process for the repair decision and allows operato rs to focus on larger leaks (as appropriate) while also addressing “quick and easy” repairs that may not have high leak rates.

Some of these factors are cons idered in LDAR regulatory prog rams (e.g., 40 C.F.R. 60, Subpart KKK) and include provisions rega rding repair timing and deferral (e.g., at next scheduled plant turn-around). Leak repair programs need to consider these same re pair or replacement considerations, timing and sc heduling requirements.

The DI&M process is explained in the referenced documents, in cluding existing EPA material, and INGAA can provide additional information if needed. A PRCI report is nearing completion that provides additional discussion on leak m itigation technologies and work practices and associated costs, and that report incl udes a detailed discussion of DI&M.

Pipeline Safety Integrity Management Will Reduce Methane Emissions

Finally, EPA should acknowledge that integrity management programs intended to improve pipeline safety have the ancillary benefit of reducing operating methane emissions. However, integrity management requirements can also result in additional methane emissions from pipeline blowdowns related to maintenance projects. When and where possible, pipeline companies employ pump-down and recompression to mini mize the release of methane during these

activities.

Inline inspection (ILI) technologies that can me asure the material strength of pipelines as effectively as, or better than, hydrostatic testing would eliminate the need for hydrostatic testing. This could greatly reduce the cost and disrupt ion caused presently by su ch testing to confirm material strength and contribute to reducing pipeline methane emissions by eliminating the need to remove natural gas from the pipeline prior to testing. To achieve these benefits, it will be critical for the Pipeline and Hazardous Materi als Safety Administration (PHMSA) to authorize the use of the new ILI technology in lieu of hydrostatic testing.

7. Coordinate Methane Initiatives across Agencies and Establish a Primary Point of Contact

As part of the Obama administration’s Climat e Action Plan, the Administration has initiated

several efforts that address methane reductions , including revisions to the EPA Natural Gas STAR Program, launch of the Quadrennial Energy Review, revision of EPA’s GHGRP, the fiveINGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 14 of 17 methane white papers and plans to revise regu lations to control VOC emissions, and possibly methane emissions from the oil and gas sector. 21 This level of simultaneous activity on a common issue challenges the indus try and other stakeholders, a nd coordination between industry and between policymakers is crucial. Theref ore, INGAA recommends that the Administration establish a primary point of contact responsib le for ensuring coordination across the multiple federal agencies and departments tasked with methane-related initiatives impacting the T&S sector. Ideally, this point of c ontact would provide guidance and assistance in the development, interpretation and implementation of methane po licies. It can be difficult for the pipeline industry to manage the numerous and someti mes duplicative requests for information from multiple agencies and departments.

As questions arise about the overall climate chan ge strategy, it would be extremely helpful to have this same primary point of contact within the Administration to discuss methane and other GHG reduction issues, opport unities and policies.

8. Conclusion

INGAA and its members are committed to redu cing methane emissions in a prudent and environmentally responsible manner, and are undert aking initiatives to und erstand the sources of T&S sector methane emissions and identify the most significant sources and the most costeffective methane emission reducti on strategies. In summary:

1. EPA should support DI&M as a mitigation strateg y. It is one of the most efficient and cost effective mitigation strategies.

2. INGAA recommends a careful review of the Subpart W data to properly understand leak frequency and distribution. A growing body of work supports the premise that a few larger leaks contribute to the va st majority of emissions.

3. INGAA disagrees that all leaks ar e cost effective to repair. Many factors influence a leak repair decision, including, but not limited to, em ission rates, reliability, material and labor costs, and schedule constraints.

4. Available technologies, including optical gas imaging (i.e., IR camera) and EPA Method 21, are adequate for detecting leaks. EP A should remove ambient/mobile remote monitoring as a leak detection technology. It does not identify a sp ecific leak source and, therefore, cannot be used for that purpose.

5. Finally, EPA should acknowledge that one of the benefits of a pipeline safety integrity management program is a reduction in emissions.

21 For example, potential revisions to 40 C.F.R., Part 60, Subpart OOOO.INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 15 of 17 INGAA appreciates the opportunity to comment on th e Leaks Paper and will continue to provide

EPA with additional information as it becomes available.

Sincerely,

Lisa S. Beal

Vice President, Environment and Construction Policy

Interstate Natural Gas Association of AmericaINGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 16 of 17 Appendix A Question and INGAA Response

1. Did this paper appropriately characterize the different studies and data sources that quantify

VOC and methane emissions from leaks in the oil and natural gas sector?

Responses are found in sections three a nd four of the INGAA comment document.

2. Please comment on the approaches for quant ifying emissions and on the emission factors

used in the data sources discussed. Please comment on the national estimates of emissions and emission factors for equipment leaks presen ted in this paper. Please comment on the activity data used to calculate these emi ssions, both on the total national and regional equipment counts.

Responses are found in sections three a nd four of the INGAA comment document.

3. Are the emission estimating procedures and le ak detection methods presented here equally applicable to oil and gas production, processi ng, and transmission and storage sectors?

A limited response is found in section four and five of the INGAA comment document.

4. Are there ongoing or pla nned studies that will substa ntially improve the current understanding of VOC and methane emissions from leaks and available techniques for detecting those leaks? Please list the additional st udies you are aware of.

A response is found in section four and five of the INGAA comment document.

5. Are there types of wells sites, gatheri ng and boosting stations, processing plants, and transmission and storage stations that are more prone to leaks than others? Some factors that could affect the potential for leaks are the num ber and types of equipment, the maintenance of that equipment, and the age of the equipment, as well as factors that relate to the local geology. Please discuss these factors and ot hers that you believe to be important.

A limited response is found in section four of the INGAA comment document.

6. Did this paper capture the fu ll range of technologies availabl e to identify leaks at oil and natural gas facilities?

Responses are found in sections four and five of the INGAA comment document.

7. Please comment on the pros and cons of the different leak detecti on technologies. Please discuss efficacy, cost and feasib ility for various applications.

Responses are found in sections four and five of the INGAA comment document.

8. Please comment on the prevalence of the use of the different leak de tection technologies at oil and gas facilities. Which technologies are the most commonly used? Does the type of facility (e.g., well site versus gathering and boosting station) affect which leak detection technology is used?

A response is found in section five of the INGAA comment document.INGAA Comments on EPA Leaks White Paper June 16, 2014

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Page 17 of 17 9. Please provide information on current freque ncies of revisit of existing voluntary leak detection programs in industry and how the cost s and emission reductions achieved vary with different frequencie s of revisit.

A response is found in section six of the INGAA comment document.

10. Please comment on the potential for using ambient/mobile monitoring technologies in conjunction with OGI technology. This woul d be a two-phase approach where the ambient/mobile monitoring technology is used to detect the presence of a leak and the OGI technology is used to identify the leaking comp onent. Please discuss efficacy, cost and feasibility.

A response is found in section five of the INGAA comment document.

11. Please comment on the cost of detecting a leak wh en compared to the cost to repair a leak. Multiple studies described in this paper suggest that detecting leaks is far more costly than repairing leaks and, due to generally low costs of repair and the subsequent product recovery, it is almost always economical to repair l eaks once they are found. Please comment on this

overall conclusion.

A response is found in section six of the INGAA comment document.

12. If the conclusion is correct that it is almost always economical to repair leaks once they are found, then how important is th e quantification of emissions from leaks when implementing a program to detect and repair leaks?

A response is found in section six of the INGAA comment document.

13. Please comment on the state of innovation in leak detection technologies. Are there new technologies under development that are not disc ussed in this paper? Are there significant advancements being made in the technologies that are not describe d in this paper?

A response is found in section five of the INGAA comment document.