# MEMORANDUM

FROM: Akachi Imegwu, U.S. EPA, Climate Change Division

TO: Docket EPA-HQ-OAR-2011-0512, Mandatory Reporting of Greenhouse Gases:

Technical Revisions to the Petroleum a nd Natural Gas Systems Category of the

Greenhouse Gas Reporting Rule

DATE: December 2, 2011

SUBJECT: Summary of comments on S ubpart W of the final Mandatory

Reporting of Greenhouse Gases Rule (40 CFR Part 98) af ter promulgation that are

addressed in the final rule action: Ma ndatory Reporting of Greenhouse Gases:

Technical Revisions to the Petroleum a nd Natural Gas Systems Category of the

Greenhouse Gas Reporting Rule

1.0 INTRODUCTION

The 2010 final rule for Subpart W of the Greenhouse Gas Reporting Rule (Subpart W)

was signed by EPA Administrator Lisa Jack son on November 8, 2010 and published in the

Federal Register on November 30, 2010 (75 FR 74458). The 2010 final rule, which became

effective on December 31, 2010, included reporti ng of GHGs from facilities containing

petroleum and natural gas systems. The rule does not require control of GHGs, rather it only

requires that facilities containi ng petroleum and natural gas systems with emissions sources

above certain threshold levels monitor and report emissions and other related data.

Since promulgation of the final rule in November 2010, EPA proposed the “ Technical

Corrections, Clarifying and Other Amendments to Certain Provisions of the Mandatory Greenhouse Gas

Reporting Rule 

# ” on August 4, 2011 (76 FR 47392) and the “Technical Revisions and

Clarifications to Subpart A, Subpart I, a nd Subpart W” on September 9, 2011 (76 FR 56010).

Stakeholders were given the opportunity to co mment on these proposed rules. As a result of

those comments, EPA is making te chnical and editorial revisions to specific provisions in

Subpart W. In addition, the Admi nistrator has identifie d within Subpart W a number of technical

issues that need to be revised and specific provisions that need to be clarified.

The purpose of this memorandum is to describe the extent of EPA’s outreach efforts for

Subpart W of Part 98, summarize specific comm ents received during the comment period, and

outline the issues being addressed by the amendments.

2.0 SUMMARY OF EPA OUTREACH ACTIV ITIES ON THE GREENHOUSE GAS

PROGRAM

EPA has conducted an extensive outreach program for the Greenhouse Gas Program,

including meetings with trade associations and individual businesse s, on-line web-based

seminars (webinars), and training sessions fo r EPA Regional Offices. A subset of those

meetings was specifically targeted for Subpart W reporters. The following table lists those

meetings and webinars that EPA has conducted to date, along with the month and year of the

# activity. When available, the table also include s the approximate attendance for the meeting or

webinar. In addition, the meetings and webinars that were specif ically targeted to subpart W

reporters are in yellow highlighted text.

POST-SIGNATURE MEETI NGS AND WEBINARS

Month and Year of Inform ation Meeting or Webinar

Organization or Location (estimat ed attendance, if available)

Sept 2009

EPA Regional Offices Briefing (100)

Agriculture community teleconference (100)

State and Local Agencies teleconference (100)

Clean Energy Group Meeting (about 40)

State of Washington (2)

Business Council (73)

Call with Massachusetts on data system (2)

Overview webinar (293)

US Climate Action Partnership (20)

Overview webinar (284)

National Cooperative Refinery Associa tion, and Van Arsdall & Associates

Oct 2009

Oil and Gas Compact (30)

Portland Cement Assoc. (20)

CENSARA(50)

Overview webinar (217)

Applicability Tool Demonstration (84)

National Lime Assoc. (3)

Detailed webinar (252)

EEI (80)

NACAA (75)

Nitric Acid and Ammonia Assoc.(30)

TFI, AISI, SMA

Overview webinar (176)

Detailed webinar (208)

Air Program Managers and staff (25)

Detailed webinar (206)

Aluminum Industry

Steel Manufacturers Assoc.

Natural Gas Star

Overview webinar (133)

Carolina Air Pollution Control Assoc. (400)

Applicability Tool Demonstration (238)

Waste Management and Equipment Companies (25)

Ohio Manure Storage

Overview webinar (251)

Corporate Climate Regulation, Chicago, IL

Midwest Transportation & Air Quality Conference

Detailed webinar (333)

# POST-SIGNATURE MEETI NGS AND WEBINARS

Month and Year of Inform ation Meeting or Webinar

Organization or Location (estimat ed attendance, if available)

TCR/CAA (90)

Environmental Groups (10)

API

NOV 2009

Misc. Meetings with Industries (Refiner ies, Pulp and Paper, Cement) (100)

Northeast Gas Assoc.

Ecology and Environment, Inc. (2)

Detailed webinar (253)

TCR

Tribal Air Coordinators (50)

GHG data exchange discussion with New Mexico (8)

API (20)

ABA (100)

Training for three regional cap and trade programs – DC (70)

State-EPA Dialogue - DC (80)

Treated Wood Council (60)

Detailed webinar (172)

MAPI (Manufacturing Alliance) (15)

Environmental Services Corporation (150)

Western Climate Initiative partner meeting – Santa Fe (50)

Detailed webinar (171)

Regional Climate sub-leads (40)

Air Products (5)

Waste Management and others (10)

Detailed webinar (96)

DEC 2009

AWMA-EPA- RTP (100)

Envirosys (4)

Detailed webinar (50)

ACC (5)

National Grid

Detailed webinar (91)

Utilitpoint and Allegro (115)

CARB

NPRA and API

Golder and Associates

Anadarko (10)

Kinder Morgan

EEI

SWANA- LFGTE

Thermo Fisher Scientific

EPA Region 4 Training (100)

Waste Management and others (8)

Air Products (5)

# POST-SIGNATURE MEETI NGS AND WEBINARS

Month and Year of Inform ation Meeting or Webinar

Organization or Location (estimat ed attendance, if available)

The Fertilizer Institute

ADM (8)

JAN 2010

Detailed webinar (83)

Air Products

National Emissions Inventory (30)

OECA- Regional offices (30)

National Grid

Alliance of Automobile Manufacturers (9)

Detailed webinar (100)

NRPA (300)

Feb 2010

Dedicated webinar for American Colleges and Universities (220)

EPA Regional Inventory, Enforcement (23)

University Challenge

State webinar (200)

Webinar (182)

Iowa Landfill operators (125), Asphalt Paving Associati on of Iowa (70), and the Iowa Chapter of AMWA

(60).

Mar 2010

Inst. Of Clean Air Companies (23)

SWANA (200)

EPA AFS Compliance Meeting

Second Nature (Colleges/Universities) Panel (20)

ECOS (50)

PCA

Training- EPA Regions 5 and 7 (180)

Iowa Landfills (50)

April 2010

Arkansas Environmental Federation, Little Rock (160)

NACAA Emissions and Modeling Committee (30)

Webinar (75)

Central TX AWMA (50)

Chicago Exchange Meeting

Exchange Network National Meeting (50)

EPA Air Division Directors (20)

National Assoc. of Clean Water Agencies

Pepsico-Frito Lay (150)

Pacific NW Legislative Energy Horizon Inst./AGA (35)

May 2010

LA, Boise, Portland Training (150, 100, 70, respectively)

ESC Users Group (150)

NCASI

EPRI CEMUG (150)

June 2010

# POST-SIGNATURE MEETI NGS AND WEBINARS

Month and Year of Inform ation Meeting or Webinar

Organization or Location (estimat ed attendance, if available)

Webinar: Q&A Session (54)

October 2010

e-GGRT Training (748)

e-GGRT Training (566)

November 2010

e-GGRT Training (521)

Webinar: Subpart FF (44)

General Stakeholder Call: Subparts RR and UU (88)

December 2010

EPA Regional Offices Briefing

NACAA

Webinar: Subpart I (71)

Webinar: Subpart W (481)

Webinar: Subparts RR and UU (77)

Webinar: e-GGRT and OTAQREG Training (386)

Webinar: Subpart W (130)

January 2011

Webinar: Subpart W (138)

Webinar: e-GGRT Training (512)

February 2011

Webinar: Overview (98)

EEI: Subpart RR

May 2011

Webinar: Overview

Webinar: Subpart OO

June 2011

Webinar: Overview

November 2011

Webinar: Subpart W



# 3.0 SUMMARY OF COMMENTS BEING ADD RESSED BY THEAMENDMENTS

EPA received over 59 comment submissions fr om 49 separate reporting entities during

the public comment period for both the Augus t 4, 2011 (76 FR 47392) proposed rule and the

September 9, 2011 proposed rule (76 FR 56010).

A portion of the comments have been re solved by providing further guidance and

clarification to re porters through responses to comments wit hout requiring a change to the rule.

However, several comments have resulted in ame ndments to specific provisions in Subpart W in

order to provide more clarity and to correct errors.

The EPA has also held meetings with severa l trade associations representing industries

affected by Part 98, and many questions were presen ted by those trade associ ations that would be

resolved through the amendments to Subpart W.

For a summary of the submitted comments which are being addressed by technical

revisions to Subpart W, please see Appendix A, “Summary of Comments Being Resolved By

# Technical Corrections, Clarifying and Other Amendments.” Any sp ecific identifying information

from the incoming questions has not been included in Appendix A.

4.0 SUMMARY OF ISSUES FROM INTER NAL REVIEW BEING ADDRESSED BY

THE AMENDMENTS

As mentioned above, not all of the corrections and other amen dments correspond directly to

questions that were raised by re porters. The need for some corrections and other amendments

were identified as a result of in ternal EPA review. For a summary of the issues that have been

raised from the EPA’s review of Subpart W of Part 98 which are be ing addressed by the 2011

“Technical Corrections, Clarifyi ng and Other Amendments”, package, please see Appendix B,

“Summary of Issues From Internal Re view Being Addressed by Amendments”.Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceSubpart W – Petroleum and Natural Gas1.Standard temperatureand pressure havebeen changed from68°F and 14.7psia to60°F and 14.7psia inequations W-1, W-2,W-5, W-13, W-14A,W-14B, W-15, W-15,W-29, W-30A, W30B, W-31, W-33, W34, and W-36, andTables W-1A, W-2,W-3, W-4, W-5, W-6,and W-7.Technical Corrections, Clarifying and Other Amendments to Certain Provisions of the MandatoryReporting of Greenhouse Gases RuleInconsistent Use of Standard ConditionsNo revisions were made in Subparts A or W to allow for the consistent use of industry standardconditions (60 oF and 14.7 psia).Even with the August 4, 2011 proposed technical amendments,there are numerous inconsistencies in the standard conditions applied in Subpart W. Thefollowing table summarizes the different temperatures used for standard conditions in Subpart W.Table 1. Summary of Standard Conditions Used in Subpart W.Equations W-1 and W-2Standard Conditions: 50.6 oF and 14.7 psia (derivation is provided in comment W.1, below)Equation W-3Standard Conditions: Equation indicates that the resulting volumetric emissions are at actualconditions, though the metered vent rate is likely to be at standard conditions , which for industrywould correspond to 60 oF and 14.7 psia§98.233(d)(4)Standard Conditions: AmineCalc uses industry standard conditions of60 oF and 14.7 psiaEquation W-4Standard Conditions: Equation indicates that the resulting volumetric emissions are at actualconditions, though inlet and outlet flow rate are likely trackedat standard conditions, which forindustry would correspond to 60 oF and 14.7 psiaAt least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference§98.233(e)(1)Standard Conditions: GlyCalc uses industry standard conditions of 60 oF and 14.7 psiaEquation W-5Standard Conditions: Provides emission factors forboth standard temperatures of 60 oF and 68 oFEquation W-6Standard Conditions: Equation indicates that theresulting volumetric emissions are at standardconditions, which for industry would correspond to 60 oF and 14.7 psiaEquation W-7Standard Conditions: Equation indicates that the resulting volumetric emissions are at actualconditions, though flow rates are likely tracked atstandard conditions, which for industry wouldcorrespond to 60 oF and 14.7 psiaEquations W-8 and W-9Standard Conditions: Equation indicates that the resulting volumetric emissions are at actualconditions, though the pressure correction resultsin standard conditions of 14.7 psia. Theequations do not include a temperature correction.Equation W-10Standard Conditions: Equation indicates that theresulting volumetric emissions are at standardconditions, which for industry would correspond to 60 oF and 14.7 psiaEquations W-11 and W-12Standard Conditions: Equation results in volumetric emissions at actual conditionsEquation W-13Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceStandard Conditions: Equation indicates that the resulting volumetric emissions are at actualconditions. ([COMMENTER] recognizes the equation iscorrected to standard conditions in theSeptember 9, 2011 amendments.)The emission factor is based on standard conditions at 60 oFand 14.7 psiaEquation W-14Standard Conditions: Equation indicates that theresulting volumetric emissions are at standardconditions, which for industry would correspond to 60 oF and 14.7 psia§98.233(j)(1)Standard Conditions: E&P Tanks uses the standard conditions associated with the input gasanalysis, which for industry would correspond to 60 oF and 14.7 psia§98.233(j)(2)-(4)Standard Conditions: Calculation methodologies willresult in volumetric emissions at standardconditions, which for industry would correspond to 60 oF and 14.7 psiaEquation W-15Standard Conditions: Calculation methodologies willresult in volumetric emissions at standardconditions. Emission factors are based on standardconditions at 68 oF and 14.7 psia. CommentW.10 below provides the emission factors for industrystandard conditions of 60 oF and 14.7 psiaEquation W-16Standard Conditions: Calculation methodologies willresult in volumetric emissions at standardconditions, which for industry would correspond to 60 oF and 14.7 psiaEquations W-17 and W-18Standard Conditions: Equations indicate that the resulting volumetric emissions are at actualconditions, however the GOR is typically reportedat industry standard conditions of 60 oF andAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference14.7 psiaEquations W-19 and W-20Standard Conditions: Equations indicate that the resulting volumetric emissions are at actualconditionsEquations W-22 through W-24Standard Conditions: Equations indicate that theresulting volumetric emissions are at standardconditions, which for industry would correspond to 60 oF and 14.7 psiaEquation W-25Standard Conditions: Calculation methodologies willresult in volumetric emissions at standardconditions. Emission factors are provided for bothstandard temperatures of 68 oF and 60 oFEquations W-26 and W-27Standard Conditions: Equations indicate that theresulting volumetric emissions are at standardconditions, which for industry would correspond to 60 oF and 14.7 psiaEquation W-29Standard Conditions: Calculation will result involumetric emissions at standard conditions.Emission factors are provided for both standard temperatures of 68 oF and 60 oFEquations W-30 and W-31Standard Conditions: Calculations will result involumetric emissions at standard conditions.Some of the emission factors in Table W-2, W¬3, W-4, W-5, W-6 and W-7 are provided forstandard conditions of 68 oF and 14.7 psia. Table 2 at the end of this document provides theemission factors for 60 oF and 14.7 psia based on a correction factor of 519.67/527.67.Equation W-32Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceStandard Conditions: Equations indicate that theresulting volumetric emissions are at standardconditions, which for industry would correspond to 60 oF and 14.7 psiaEquations W-33 and W-34Standard Conditions: Converts actual volumetricemissions to standard conditions, which forindustry would correspond to 60 oF and 14.7 psiaEquation W-35Standard Conditions: Equation indicates that theresulting volumetric emissions are at standardconditions, which for industry would correspond to 60 oF and 14.7 psiaEquation W-36Standard Conditions: Calculation will result involumetric emissions at standard conditions.Density factors are provided for both standard temperatures of 68 oF and 60 oFEquations W-37, W-38, and W-40Standard Conditions: Equations result in mass emissionsEquation W-39Standard Conditions: Equation indicates the resulting volumetric emissions are at actualconditions, though gas volumes are likely trackedat standard conditions, which for industrywould correspond to 60 oF and 14.7 psia[COMMENTER] strongly insists that EPA should allow the use of industry standard conditionsof 60 oF and 14.7 psia for all Subpart W equations used toquantify and report volumetricemissions for individual sources. This would reduce the potential for error in tracking standardvolumes for the regulatory program that differ from those usually tracked for industry operations.If EPA needs the volumetric data at 68 oF for EPA’s purposes, [COMMENTER] requests thatreporters should be allowed to make a singlefinal conversion (under §98.233(t)) in which theyAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencewould convert volumetric emissions from 60 oF to68 oF by using the ratio of 527.67/519.67 asthe applicable temperature correction. Providingconsistency in the application of industrystandard conditions for the source-specific calculations will reduce burden, increase consistency,and improve data quality while ultimately once the emissions are converted to a metric tons basis,the mass emissions reported to EPA would be identical.2.Clarified 98.232(a)Revision:98.232(a) indicates “You must report CO2, CH4, and N2O emissions from eachAt least 1Commentbased on changesindustry segment specified in paragraph (b) through (i) of this section, CO2, CH4, and N2Oindividual.Submissionassociated withemissions from each flare as specified inparagraph (j) of this section, and stationary and portableremoving 98.232(j).combustion emissions as applicable as specifiedin paragraph (k) of this section” (emphasisadded).Comment:Paragraph (j) language wasdeleted and paragraph (j) is now [Reserved]. Thereference to paragraph (j) in this section should be deleted. [Flare emissions will be covered inparagraphs (b) through (i).]3.Amending the termRevision:EPA revised Equation W-10, but not as API had requested in our July 29, 2011At least 1Comment“sales pipeline” tocorrespondence to EPA.individual.Submission“flow-line.”Comment:In an e-mail provided to EPA on July 29, 2011, API provided regulatory revisions toEquation W-10. API proposed to remove the subtraction of the SG term and define the “flowback volume” term in Equation W-10 by limiting it only to the time span during which gas isactually vented to the atmosphere or flared. The SGpterm should be removed and FRM should berevised to reflect venting to the atmosphere. SGpis not needed since T is defined as the hoursvented. If a well is venting, then it is not recovering to sales.These proposed revisions add clarity, simplify the calculation, and reflect the emissionscharacteristics of flow-back operations. Without the removal of the SG term, Equation W-10 hasthe potential to either lead to the calculation ofa negative emissions value, or compare emissionsvalues vented to the atmosphere to sales valuesthat are produced against the back-pressure of agathering or sales pipeline; these are two completely different operating scenarios. API’sAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceproposed mark-ups to incorporate the changes for 98.233(g) are provided in Section 4 of thesecomments.EPA has added language defining the number of measurements required based on the number ofworkovers/completions. API interpretsthis requirement to apply to the sub-basin. Clarification isneeded that the number of measurements requiredis relative to a sub-basin or basin (facility) andwell type combination and not totalnumber of completions/workovers.In addition, API requests the addition of a newequation that sums available measurements andeliminates the need for normalizing and trackingcumulative venting time. Some companies areplanning to measure the venting associatedwith gas well completion and workovers withhydraulic fracturing. Equation W-10 does not allow the use the actual measurements. API hasincluded this new equation in the proposed revisions provided in Section 4 below.Revision:EPA has proposed corrections to Equation W-9.CommentAPI recognizes that EPA has inadvertently replicated Equation W-8 as Equation W-9in the August 4, 2011 revisions, but has updated the equation in the September 9, 2011 revisions.API will comment on the September 9 amendment separately.API provides the following corrected version of Equation W-9:Where:Esa,n = Annual natural gas emissions instandardcubic feet/year.Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceW = Number of wells with well venting for liquids unloading at the facility.0.37×10-3= {3.14 (pi)/4}/{14.7*144} (psia converted to pounds per square feet).TDW= Tubing diameter for each well, in inches.WDW= Tubing depth to plunger bumper for each well, in feet.SPW= Sales lineSurface pressure for each well, in pounds per square inchatmosphericabsolute (psia).NVVW= Number of vents per year per well.SFRW= Average sales flow rate of each gas well in standard cubic feet per hour.HRV,W= Hours that each well was left open to the atmosphere during each unloadingevent.0.5 = Hours for average well to blowdowntubing volume at sales line pressure.ZV,W= If HRV,Wis less than 0.5 then ZV,Wis equal to 0. If HRV,Wis greater than orequal to 0.5 then ZV,Wis equal to 1.API requests that EPA modify the equation toapply the surface pressure. The use of thesales line pressure has no bearing for wellson compression. Using the sales line pressurein this situation will over-estimate emissions.EPA uses “pounds per square inch atmosphere”, while the correct terminology is “poundsper square inch absolute” which is gauge pressure + 14.7 psi and is consistent with thepressure adjustment included in the 0.37×10-3constant.§98.233(f)(3)(i) references §8.233(t) to adjustthe natural gas volumetric emissions atstandard conditions. This adjustment double corrects the gas volume for pressure, whichis already included in the 0.37×10-3constant. API recommends removing the reference to§98.233(t) and defining SFRWand Ea,nin terms of gas volumes at standard conditions (60oF and 14.7 psia),as shown above.API requests the use of Methodology 3 for wells without plunger lifts. Methodology 3specifies that it can be used only for tubing wells with plunger lifts. However, there areAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceseveral instances in the field where one wouldhave tubing wells without plunger lifts. Inthose instances there is no other methodology provided to calculate emissions.4.Clarified theparameter “GHGi” inEquation W-1, W30A, W-30B, and W31.Revision:EPA added a time term to equation W-1 toaccount for the duration the device isoperational for the reporting year. T is defined as“Total number of hours in the operating year thedevices were operational.”Comment:The term “T” should refer to an estimatedaverage annual time for all the devices orallow the use of 8760 hours. An estimate of the time is consistent with the preamble languagestating “EPA is also proposing to amend Equation W-1 to include a parameter ‘T’ that estimatesthe total number of hours the devices were operational” (emphasis added).Further for this equation, the term “Masss,i”, does not need the subscript “s”, and the definitiondoes not need “at standard conditions” as massdoes not change based on temperature andpressure. [COMMENTER] also requests the term Masss,ibe revised to “mass per type of device”for the different pneumatic device types.The term GHGirefers to “onshore petroleum and natural gas production facilities” and referencesparagraph (u)(2)(i), which is defined as “sub-basin”. However, to be consistent with this equationand the methodology for compiling pneumatic device counts, GHGishould be representative ofall the wells in the basin with a particular devicetype and not aligned with a sub-basin. Revisionsto 98.233(u)(2)(i) to address this are provided in comment W.33.At least 1individual.CommentSubmission(r) Population count and emission factors.GHGi= For onshore petroleum and natural gasproduction facilities and onshore natural gasprocessing facilities, concentration of GHGi, CH4 or CO2, in produced natural gas or feed naturalgas; for other facilities listed in§ 98.230(a)(4) through (a)(8), GHGiequals 1 for CH4 and 1.1 ×10-2for CO2[add: , or use the gas composition allowed in §98.232(m)].Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference5.Clarified theparameter “Mass” inEquation W-1,Equation W-36, W-37,and W-38, andassociated parametersfor calculating GHGemissions from naturalgas pneumatic deviceventing.Revision:EPA added a time term to equation W-1 toaccount for the duration the device isoperational for the reporting year. T is defined as“Total number of hours in the operating year thedevices were operational.”Comment:The term “T” should refer to an estimatedaverage annual time for all the devices orallow the use of 8760 hours. An estimate of the time is consistent with the preamble languagestating “EPA is also proposing to amend Equation W-1 to include a parameter ‘T’ that estimatesthe total number of hours the devices were operational” (emphasis added).Further for this equation, the term “Masss,i”, does not need the subscript “s”, and the definitiondoes not need “at standard conditions” as massdoes not change based on temperature andpressure. [COMMENTER] also requests the term Masss,ibe revised to “mass per type of device”for the different pneumatic device types.The term GHGirefers to “onshore petroleum and natural gas production facilities” and referencesparagraph (u)(2)(i), which is defined as “sub-basin”. However, to be consistent with this equationand the methodology for compiling pneumatic device counts, GHGishould be representative ofall the wells in the basin with a particular devicetype and not aligned with a sub-basin. Revisionsto 98.233(u)(2)(i) to address this are provided in comment W.33.At least 2individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencePneumatic controller operating hours: The Proposed Rule adds annual operating hours as aparameter in Equation W-1. Operators shouldbe allowed to assume 8760 operating hours,with actual hours used at the operator's discretion.Equation W-1 in §98.233(a) calculates emissionsfrom pneumatic controllers. The Proposed Rulerevises the equation to add a new parameter "T",which is defined as, "The total number of hoursin the operating year that the devices wereoperational." Previously, Equation W-1 assumedcontinuous operation for the entire year – i.e., 8760 annual operatinghours. In addition tosubstituting "controllers" for "devices" per the previous comment, [COMMENTER] stronglyrecommends that Subpart W clearly indicate that 8760 hours can be assumed as a default valuefor "T". The proposed revision will have a minimal impact on inventory estimate accuracy, and inmany cases operators have already set up reporting programs based on the 8760 operating hourassumption. EPA should not add unnecessary costs and complications by mandating that annualoperating hours is defined forpneumatic controllers. [COMMENTER] recommends that SubpartW include the following revisions for the description of "T" in the list of variable that followsEquation W-1:"T = Total number ofannual operatinghours for in the operating yearthecontrollersdeviceswere operational.8760 annual operating hours can be used as a default assumption."6.Clarifying theRevision:EPA added a time term to equation W-2 toaccount for the duration the pneumaticAt least 1Commentparameter T inpump is operational for the reporting year.individual.SubmissionEquation W-2 andassociated parameters.Comment:The terms defined for Equation W-2 include “24 * 365 = Conversion to yearlyemissions estimate”. This term is no longer usedin the equation and should be deleted from thelist of terms.The term “T” should refer to an estimated average annual time for all the pumps or allow the useof 8760 hours. An estimate of the time is consistent with the preamble language stating “We areproposing to amend Equation W–2 in 40 CFR98.233(c), which is used for calculating GHGAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceemissions from natural gas pneumatic pump venting, to include a parameter ‘‘T’’ that estimatesthe total amount of hours the pumps were operational” (emphasis added).Further for this equation, the term “Masss,i”, does not need the subscript “s”, and the definitiondoes not need “at standard conditions” as massdoes not change based on temperature andpressure.The term GHGirefers to “onshore petroleum and natural gas production facilities” and referencesparagraph (u)(2)(i), which is defined as “sub-basin”.However, to be consistent with this equation,GHGishould be representative of all the wells in the basin with a pneumatic pump and notaligned with a sub-basin. Revisions to 98.233(u)(2)(i) to address this are provided in commentW.337.Modified paragraph98.233(d) (1) to allowthe use ofmanufacturer’sinstruction or industrystandard practice forCEMS on AGRs.(1) Calculation Methodology 1. If you operateand maintain a CEMS on an AGR exhaust stackthat has both a CO2 concentration monitor and volumetric flow rate monitor, you must calculateCO2 emissions under this subpart by followingthe Tier 4 Calculation Methodology and allassociated calculation, quality assurance, reporting,and recordkeeping requirements for Tier 4 insubpart C of this part (General StationaryFuel Combustion Sources). For existing continuousmonitoring equipment on AGR vents, and for continuous monitoring equipment on noncombustion AGR vents, the calculation, quality assurance, reporting, and recordkeepingrequirements of 98.33(a)(4) and 98.34(c) may alternatively be satisfied by following thecalculation, quality assurance, reporting, and recordkeeping requirements in a permit or therecommendations of the manufacturer of the monitoring equipment or general industry practice.If a CO2 concentration monitor and volumetric flowrate monitor are not available, you may electto install a CO2 concentration monitor and volumetric flow rate monitor that comply with all ofthe requirements specified for the Tier 4 Calculation Methodology in subpart C of this part(General Stationary Fuel Combustion). The calculation and reporting of CH4 and N2O emissionsis not required as part of the Tier 4 requirements for AGRs.”At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference8.Added Equations W4A and W-4B forcalculating emissionsfrom an AGR usinginlet and outlet gascompositions and flowrates.Revision:EPA has modified Equation W-4 for calculating CO2 emissions from acid gas removalunits. EPA notes in the preamble that the correction was needed because the original equationintroduces an error that increases significantly when the amount of CO2 in the gas increases.Comment:The previous (original) equation containeda variable, alpha, to adjust the calculationbased on whether the inlet gas or outlet gas flowrate was applied. Note, the definition of termsstill lists the term alpha, although alpha is not used in the revised equation.The proposed correction seems to introduce a largererror than the original equation if the inletgas volume is applied. Testing the equationsusing the onshore production example facility fromthe Compendium (Section 8.1.1), results in the following:Compendium Method1,190 scf CO2/yrOriginal EPA Method: Applying inlet gas flow 1,183 scf CO2/yrOriginal EPA Method: Applying outlet gas flow 1,154 scf CO2/yrRevised EPA Method: Applying inlet gas flow 1,337 scf CO2/yrRevised EPA Method: Applying outlet gas flow 1,169 scf CO2/yr[The Compendium example is based on the following conditions: AGR inlet gas flow = 10,290scf/yr, inlet gas CO2composition is 12%, AGR outlet gas flow rate = 8,997 scf/yr, outlet gas CO2composition is 0.5%.]At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceWhen the inlet volume of gas is used, the proposed corrected equation over estimates emissionsby incorrectly increasing the volume of inletgas. Based on [COMMENTER]’s analysis, it doesnot appear that the revision improves the quality of data when the inlet gas flow rate is applied.[COMMENTER] requests that EPA retain the previous equation, using the alpha term. Asdemonstrated in the table above, the revisedequation actually introduces a larger error,particularly when the inlet gas flow rate is applied.[COMMENTER] also requests that the flow rate term “V” be defined in terms of standardconditions (60oF and 14.7 psia), consistent with the flow measurements available for amine units.In addition, the term Ea,CO2.should be revised to Es, CO2and be expressed in volumetric emissionsat standard conditions (60oF and 14.7 psia). With this revision, paragraph (9) is no longer needed.9.Clarified theRevision:EPA added a definition for the “1000”term used in Equation W-5.At least 1Commentparameter ‘1000’ inindividual.SubmissionEquation W-5.Comment:[COMMENTER] requests the following revision to this definition: “1000 =Conversion of EFiin thousand standard cubic feet to standardcubic feet.”10.Clarified paragraph98.233 (e)(5) thatemissions aredetermined for allrefilling processes thatoccur during thecalendar year.Comment:EPA has not proposed revisions to Equation W-6. However, [COMMENTER] notesthefollowing technical corrections for this equation:•§98.233(e)(5) indicates that Equation W-6 is to be used every time the dehydrator it isdepressurized for the desiccant refilling process.As a result, the parameter T and themultiplier of 365 days/yr should beremoved from the equation.•If Es,nis an annual number, the equation should include aΣof depressurizations forrefilling.At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference11.Modified parametersunder Equation W-8Revision:EPA has modified the summation terms in Equation W-8 to account for the pressureand tubing diameter groupings.Comments:•[COMMENTER] appreciates that EPA has corrected Es,nand SFRqto be stated in standardconditions, not actual conditions.•For clarity, the term CDpin Equation W-8 should indicate that this is the internal diameter,which is consistent withthe calculation approach.•On page 54 of Appendix D in the Technical Support Document associated with theseproposed amendment, EPA indicates that the pressure in Equation W-8 is the reservoir shutin pressure. EPA comments that this informationis not reliably available in public literature.[COMMENTER] agrees with this assessment, butfurther would like to point out thatreservoir shut-in pressure is not reliably available in operations either. The term SPpshouldrepresent the surface pressure prior to venting,in pounds per square inch absolute (notatmosphere).•In the list of defined terms for Equation W-8, the term HRQ,PWshould be HRq,p.•EPA has clarified that the term WDpis the distance between thelowest packer to the bottomof the well. It is unclear what value should be applied for WDpfor wells without packers.•The amendments did not change 98.233(f)(2)(i)which references 98.233(t) to adjust thenatural gas volumetric emissions at standardconditions. This adjustment double corrects thegas volume for pressure, which is already included in the 0.37×10-3constant.[COMMENTER] recommends removing the reference to §98.233(t) since SFRqand Es,naredefined in terms of gas volumes at standard conditions (60 oF and 14.7 psia).At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceEquation W-8 should be replaced with the following:Where:Esa,n = Annual natural gas emissions at actual conditionsin standard cubic feet/year.W = Number of wells with well ventingfor liquids unloading at the facility.0.37×10-3= {3.14 (pi)/4}/{14.7*144} (psia converted to pounds per square feet).CDW= Casing diameter for each well, in inches.WDW= Well depth to first producing horizon for each well, in feet.SPW= Shut-inSurface pressure prior to venting for each well, in pounds square inchatmosphereabsolute (psia).VW= Number of vents per yearper well. (Note, the secondsummation was changed fromV to VWin the revised equation above to reflect this term.)SFRW= Average sales flow rate of each gas well in cubic feet per hour.HRV,W= Hours that each well was left open tothe atmosphere during each unloadingevent.1.0 = Hours for average well to blowdown casing volume at shut-in pressure.ZV,W= If HRV,Wis less than 1.0 then ZV,Wis equal to 0. If HRV,Wis greater than or equalto 1.0 then ZV,Wis equal to 1.In the equation above, [COMMENTER] requests that the SPpterm represent surfacepressure prior to venting, in pounds per square inch absolute. As EPA had definedSPp, the shut-in pressure is interpreted to refer to the bottom-hole or casing pressure,which is not readily available.Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceEPA uses “pounds per square inch atmosphere”, while the correct terminology is“pounds per square inch absolute” which is gauge pressure + 14.7 psi and isconsistent with the pressure adjustment included in the 0.37×10-3 constant.§98.233(f)(2)(i) references §98.233(t)to adjust the naturalgas volumetric emissionsat standard conditions. This adjustmentdouble corrects the gas volume for pressure,which is already included in the 0.37×10-3 constant. [COMMENTER] notes that theAugust 19 amendments remove the reference to §98.233(t) and define SFRW interms of gas volumes at standard conditions (60 oF and 14.7 psia). As indicatedabove, the term Ea,nshould also be defined in terms of gas volumes at standardconditions (60 oF and14.7 psia).12.Modified parametersRevision:EPA revised Equation W-9.At least 1Commentunder Equation W-9individual.Submissionand removed referenceComments:to paragraph 98.236(t).•[COMMENTER] appreciates that EPA has corrected Es,nand SFRqto be stated in standardconditions, not actual conditions.•For clarity, the term TDpin Equation W-9 should indicate that this is the internal diameter,which is consistent withthe calculation approach.•The term SPpshould be the flowing wellhead pressure, not the sales line pressure which has nobearing for wells on compression. Using the sales line pressure in this situation will overestimate emissions. SPpshould also be expressed as pounds per square inch absolute, (notatmosphere) which is gauge pressure + 14.7 psi and is consistent with the pressure adjustmentincluded in the 0.37×10-3constant.•The amendments did not change 98.233(f)(3)(i)which references §8.233(t) to adjust thenatural gas volumetric emissions at standardconditions. This adjustment double corrects thegas volume for pressure, which is already included in the 0.37×10-3constant. [COMMENTER]recommends removing the reference to §98.233(t) since SFRqand Es,nare defined in terms ofgas volumes at standard conditions(60 oF and 14.7 psia).Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference•[COMMENTER] requests the use of Methodology 3 for wells without plunger lifts.Revision:EPA has proposed corrections to Equation W-9.Comment[COMMENTER] recognizes that EPA hasinadvertently replicated EquationW-8 as Equation W-9 in the August 4, 2011 revisions, but has updated the equation in theSeptember 9, 2011 revisions. [COMMENTER] will comment on the September 9amendment separately.[COMMENTER] provides the following corrected version of Equation W-9:Where:Esa,n = Annual natural gas emissionsin standard cubic feet/year.W = Number of wells with well ventingfor liquids unloading at the facility.0.37×10-3= {3.14 (pi)/4}/{14.7*144} (psia converted to pounds per square feet).TDW= Tubing diameter for each well, in inches.WDW= Tubing depth to plunger bumper for each well, in feet.SPW= Sales lineSurface pressure for each well, in pounds per square inchatmosphericabsolute (psia).NVVW= Number of vents per year per well.SFRW= Average sales flow rate of each gas well in standard cubic feet per hour.HRV,W= Hours that each well was left open tothe atmosphere during each unloadingevent.0.5 = Hours for average well to blowdowntubing volume at sales line pressure.ZV,W= If HRV,Wis less than 0.5 then ZV,Wis equal to 0. If HRV,Wis greater than orAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceequal to 0.5 then ZV,Wis equal to 1.[COMMENTER] requests that EPA modifythe equation to apply the surfacepressure. The use of the sales line pressure has no bearing for wells oncompression. Using the sales line pressurein this situation will over-estimateemissions.EPA uses “pounds per square inch atmosphere”, while the correct terminology is“pounds per square inch absolute” which is gauge pressure + 14.7 psi and isconsistent with the pressure adjustment included in the 0.37×10-3constant.§98.233(f)(3)(i) references §8.233(t) to adjust the natural gas columetricemissions at standard conditions. Thisadjustment double corrects the gas volumefor pressure, which is already included in the 0.37×10-3constant.[COMMENTER] recommends removing thereference to §98.233(t) and definingSFRWand Ea,nin terms of gas volumes at standard conditions (60 oF and 14.7psia),as shown above.[COMMENTER] requests the use of Methodology 3 for wells without plungerlifts. Methodology 3 specifies that it can be usedonly for tubing wells withplunger lifts. However, there are severalinstances in the field where one wouldhave tubing wells without plunger lifts.In those instances there is no othermethodology provided tocalculate emissions.13.Added Equation W-Revision:EPA revised Equation W-10, but not as [COMMENTER] had requested in our July 29,At least 1Comment10B, supporting2011 correspondence to EPA.individual.Submissionparameters, and text to98.233(g).Comment:In an e-mail provided to EPA on July 29,2011, [COMMENTER] provided regulatoryrevisions to Equation W-10. [COMMENTER] proposedto remove the subtraction of the SG termand define the “flow-back volume” term in Equation W-10 by limiting it only to the time spanAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceduring which gas is actually vented tothe atmosphere or flared. The SGpterm should be removedand FRM should be revised to reflect venting to the atmosphere. SGpis not needed since T isdefined as the hours vented. If a well is venting, then it is not recovering to sales.These proposed revisions add clarity, simplify the calculation, and reflect the emissionscharacteristics of flow-back operations. Without the removal of the SG term, Equation W-10 hasthe potential to either lead to the calculation ofa negative emissions value, or compare emissionsvalues vented to the atmosphere to sales valuesthat are produced against the back-pressure of agathering or sales pipeline; these are twocompletely different operating scenarios.[COMMENTER]’s proposed mark-ups to incorporate the changes for 98.233(g) are provided inSection 4 of these comments.EPA has added language defining the number of measurements required based on the number ofworkovers/completions. [COMMENTER] interprets this requirement to apply to the sub-basin.Clarification is needed that the number of measurements required is relative to a sub-basin orbasin (facility) and well type combination and not total number of completions/workovers.In addition, [COMMENTER] requests the addition of a new equation that sums availablemeasurements and eliminates the need for normalizing and tracking cumulative venting time.Some companies are planning to measure the venting associated with gas well completion andworkovers with hydraulic fracturing. Equation W-10 does not allow the use the actualmeasurements. [COMMENTER] has included this new equation in the proposed revisionsprovided in Section 4 below.14.Clarified inRevision:EPA revised Equation W-10, but not as [COMMENTER] had requested in our July 29,At least 1Comment98.233(g)(1) that the2011 correspondence to EPA.individual.Submissionnumber ofmeasurements orComment:In an e-mail provided to EPA on July 29,2011, [COMMENTER] provided regulatorycalculations requiredrevisions to Equation W-10. [COMMENTER] proposedto remove the subtraction of the SG termAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceare dependent on theand define the “flow-back volume” term in Equation W-10 by limiting it only to the time spannumber workover orduring which gas is actually vented tothe atmosphere or flared. The SGpterm should be removedcompletions done in aand FRM should be revised to reflect venting to the atmosphere. SGpis not needed since T issub-basin category.defined as the hours vented. If a well is venting, then it is not recovering to sales.These proposed revisions add clarity, simplify the calculation, and reflect the emissionscharacteristics of flow-back operations. Without the removal of the SG term, Equation W-10 hasthe potential to either lead to the calculation ofa negative emissions value, or compare emissionsvalues vented to the atmosphere to sales valuesthat are produced against the back-pressure of agathering or sales pipeline; these are twocompletely different operating scenarios.[COMMENTER]’s proposed mark-ups to incorporate the changes for 98.233(g) are provided inSection 4 of these comments.EPA has added language defining the number of measurements required based on the number ofworkovers/completions. [COMMENTER] interprets this requirement to apply to the sub-basin.Clarification is needed that the number of measurements required is relative to a sub-basin orbasin (facility) and well type combination and not total number of completions/workovers.In addition, [COMMENTER] requests the addition of a new equation that sums availablemeasurements and eliminates the need for normalizing and tracking cumulative venting time.Some companies are planning to measure the venting associated with gas well completion andworkovers with hydraulic fracturing. Equation W-10 does not allow the use the actualmeasurements. [COMMENTER] has included this new equation in the proposed revisionsprovided in Section 4 below.15.Equation W-11C isused to determinewhether the backflowduring workovers andRevision:EPA has added Equation W-11C to determine whether the flow rate is sonic orsubsonic. Flow is sonic if the value of R is greater than 2.At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencecompletions isComment:[COMMENTER] appreciates the clarity provided by documenting the equationpredominantly sonicdetermining if the flow rate is sonic orsub-sonic. However, Methodology 2 does notor subsonic.acknowledge that a single completion or workover can alternate between sonic and sub-sonicflows. As [COMMENTER] pointed out in a letter to EPA on May 13, 2011, flowback on anysingle completion will be partially supersonic and partially subsonic.Reporters cannot discernexactly when flowback falls into either category during a completion. Additionally, liquids andgases flow at different rates. As a completion progresses, the amount of liquids decreases and theamount of gases increases, which makes performing the calculations more difficult. EPA shouldreplace this methodology with a single calculationfor tracking pressure drop across the choke,with assumptions for choke flow and gas gravity. Such a calculation will be technically feasibleand sufficient for policy purposes.16.Clarified Equation W-Revision:EPA has addressed gas volumes at standard conditions and the sub-basin categoryAt least 1Comment13 by changing theapproach in revisions to the definition of terms for Equation W-13.individual.Submissionparameter “Vf” and“Tf” to “Vp” and “Tp”.Comment:EPA has changed Vfand Tfto Vpand Tp, respectively in the definitions, but didnot change the variable subscripts in the equation. Also, the term “Vv” is defined in terms ofeach blowdown “i”. However, the subscript “i”is not used in either Equation W-14A or W14B. [COMMENTER] believes “i” should be replaced with “p”.17.Clarified theparameter definition of“Nwo”.Revision: Under §98.236(c)(6)(ii)(B), EPA clarified that the total count of workovers in thecalendar year should be reported for those that flare gas or vent to the atmosphere.Comment:[COMMENTER] supports this revision. However, [COMMENTER] requests similarclarification be added to the definition of theterm “N” in Equation W-13 to reflect that thenumber of workovers in the equation reflect thosethat flare gas or vent gas to the atmosphere.At least 1individual.CommentSubmission18.Clarified paragraph98.233(i)(1) as towhether emergencyEPA should clarify that emergency events are excluded from blowdown vent stackreporting. Revisions in the Proposed Rule conflict with the August 4 proposed revisions.Additional revisions are needed to clarify Subpart W requirements.At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceblowdown events areincluded.As indicated in September 19, 2011 comments to EPA, [COMMENTER] supports the August 4proposed revision that excludes emergency eventsfrom the definition of "blowdown vent stack ".However, the Proposed Rule confuses this issue in revisions to the introductory text of§98.233(i). The Proposed Rule should be revised to clearly indicate that emergency events areexcluded from blowdown vent stack reporting.The August 4 proposed rule revisions [76 FR 47392] revised the definition of blowdown ventstack:"Blowdown vent stackemissions mean natural gas and/or CO2 released due to maintenanceand/or blowdown operations including compressor blowdown and emergency shut-down (ESD)system testing.Emissions from emergency events are not included."The new closing sentence clearly indicates thatemergency venting isexcluded from blowdownvent stack reporting. [COMMENTER] supports this revision. However, the Proposed Ruleintroduction to §98.233(i) confuses issue. Revisedtext from EPA's redline version of the ruleavailable in the docket is shown here, but the last sentence isnotincluded in the publishedProposed Rule:"Calculate CO2 and CH4 blowdown vent stackemissions from depressurizing equipment toreduce system pressure for planned or emergency shutdowns or to take equipment out ofservice for maintenancethe atmosphere(excluding depressurizing to a flare, over-pressurerelief, operating pressure controlventing and blowdownof non-GHG gases; desiccant dehydratorblowdown venting before reloading is covered inparagraph (e)(5) of this section) as follows(Emissions from emergency vents are not included.):"In this revised text, the text "or emergency" contradicts the revised §98.6 definition of blowdownvent stack and the text in the closing sentence of the EPA redline version. Both of these excludeAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceemergency events and indicateEPA intended to exclude the reporting of emergency ventingemissions. To clarify and avoid conflict withthe §98.6 definition, the phrase “or emergency”should be deleted. [COMMENTER] also recommends including the closing sentence with theother list of excluded activities and referring to emergencyeventsrather than emergencyvents.The [COMMENTER] recommended revisions based on the EPA redlines above follows:"Calculate CO2 and CH4 blowdown vent stackemissions from depressurizing equipment toreduce system pressure for planned or emergencyshutdowns or to take equipment out ofservice for maintenancethe atmosphere(excluding depressurizing to a flare, over-pressurerelief, operating pressure control venting and blowdown of non-GHG gases, and emissions fromemergency events; desiccant dehydrator blowdown venting before reloading is covered inparagraph (e)(5) of this section) as follows(Emissions from emergency vents are notincluded):"19.Clarified parameters inRevision:The preamble (page 56020) indicates that EPA is providing reporters the option ofAt least 1CommentEquation W-14A andtracking blowdowns by each occurrence for the same blowdown volume: “To enable facilities toindividual.SubmissionW-14B.retain their current tracking system, we are proposing to add an optionfor calculating emission byequipment type” (emphasis added). However, theregulatory language does not provide an option,but rather blends the two approaches. 98.233(i)(3) requires calculating the total emissions foreach equipment typeusing either Equation W-14A or W-14B. While, the term “N” used in theseequations is defined as the number of repetitive blowdowns for each unique volume in thecalendar year.Comment:[COMMENTER] suggests that EPA revise the definition of term “N” to present theoption of using unique volumeor equipment: “N= number of repetitive blowdowns for eachunique volume or equipment typein calendar year.”EPA should similarly revise the text under 98.233(i)(3): “Calculate the total annual ventingemissions for each unique volume or equipment type ...”.Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference[COMMENTER] also requests that EPA deletethe words “and mass” under 98.233(i)(5). Thiscorrection is consistent with the calculation approach for blowdown vent stacks which result involumetric emissions, not mass.20.Removed paragraph98.233(i)(5).Revision:EPA revised 98.233(i)(5) to reference emissions determined under Equations W-14Aand W-14B.Comment:98.233(i)(5) requires calculating the total annual venting emissions for all blowdownvent stacks “by adding all standard volumetricand mass emissions determined using EquationsW-14A and W-14B.” [COMMENTER] requests the phrase “and mass” be deleted from thisstatement as neither Equations W-14A nor B result in mass emissions. Paragraph (5) should beplaced before paragraph (4), which references 98.233(v) for the conversion of volumetricemissions to mass emissions.At least 1individual.CommentSubmission21.Revised Equation W16.Revision:In Equation W-16, EPA added a correction to the first part of the equation toconvert the time aspect of the emission factorfrom an annual basis to an hourly basis.Comment:The proposed revisions did not correct the units in the second part of the equation.The correct equation should be:At least 1individual.CommentSubmission22.Modified paragraph98.233(l) regardingemissions from welltesting venting andG. Well testing venting and flaringOn page 56031 of the September 9,2011 preamble, EPA is addressingwell testing and ventingand flaring. Among other things, EPA is considering, but has not yet proposed, using theproduction rate to estimate the volume of emissions from venting and testing gas wells thatAt least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceflaring.produce dry gas. EPA is soliciting comments on this suggested provision for gas wells.Commenter Response:Commenter agrees that production rate could be used as an estimate of gas flow rate.23.Amended EquationW-18 to reportemissions at a facilitylevel.Revision:For associated gas venting and flaring, EPAhas replaced field with sub-basin categoryfor determining the separator oil composition and Reid vapor pressure.Comment:[COMMENTER] supports the revision forsub-basin. However, sub-basin hereshould apply to oil wells based on the “oil formation” sub-basin category proposed by[COMMENTER] above. In addition, [COMMENTER] interprets “associated gas” to meannatural gas produced with crude oil that is not recovered for sales due to the lack of infrastructure.This is consistent with a response EPA posted to the list ofFrequently Asked Questions onSubpart W, which indicated “Section 98.233(m) only covers natural gas that is not recoveredfrom the production operation.”With the introduction of the sub-basin concept, it is now unclear what the geographic boundariesare for the volume term used in Equation W-18.The objective of the sub-basin approach is toreduce sampling burden. [COMMENTER] requests that EPA clarify that the volume used inEquation W-18, and the resulting emissions from Equation W-18, represent the oil formation atthe entire basin level. Paragraph (1) should bemodified to state “If GOR from each well is notavailable, the GOR from a cluster of wells in the [add (red): basin] shall be used.” With thesechanges, the terms in Equation W-18 will be consistent with the reporting requirements under98.236(c)(11)(iii) and (iv).At least 1individual.CommentSubmission24.Added Equation W­Metering-Regulating Station SamplingAt least 3Comment30B, amendedindividual.SubmissionEquation W-32,The Final Rule requires that leak surveys be conducted at all metering-regulating (M&R) stationsamended text inclassified as "custody transfer city gate stations." We agree that this definition has problems,98.233(q) and (r) tobecause it attempts to capture ownership change(custody transfer) and pressure change (cityAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceallow reporters toconduct leak detectionat T-D transfer stationsover a five yearperiod.gate) within the same definition. Those twoclasses of stations do not necessarily overlap.The Proposed Rule discards those qualifying terms and instead requires surveys at alltransmission distribution stations. While this definition is perhaps more clear, the number ofstations that must be surveyed is greatlyincreased, thus putting an undue burden on LDCs. Werespectfully disagree with the EPA's statement that "the proposed revisions primarily provideadditional clarifications or flexibility regarding the existing regulatory requirements, [and]generally do not affect the type of informationthat must be collected ...." For example, under theFinal Rule, PSNC would be required to leak survey18 M&R stations in its entire system. This isthe number of "custody transfer" M&R stationswithin the PSNC system. Under the ProposedRule, the number of transmission-distribution stations that must be surveyed increases to morethan 450. Our SCE&G subsidiary would experience a similarly impossible number to survey in2011. A survey of this magnitude cannot possiblybe conducted with but a few months remainingin the year.Furthermore, we believe that a survey of thissize will not yield significantly better informationthan a smaller survey. If it is EPA's goal to havea statistically sound number of M&R stationssurveyed, then it is appropriate touse other factors to reduce the number of stations surveyed. Wesuggest two possible ways to limit the surveyed subset of stations:1. Survey only those stations that flow a significant amount of gas at any point during the year.This flow range could be based on actual gas measurements or determined by flow models basedon actual system conditions. This method is attractive because it would remove from the subsetall M&R stations that serve only handfuls of customers. For example, if only stations that hadmodeled flows of 200 cubic feet per hour (cfh) ormore were included in the PSNC survey, thesurveyed subset would be cut to 68 stations from 450 stations.2. Survey a defined percentage of M&R stations.For example, 10% of all M&R stations might beincluded in the survey, perhaps subject to a minimum and maximum number of stations. ThisAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencemethod might be attractive because the 10% of surveyed stations could include stations of allsizes and types, thus creating a more representativeemission factor to apply to the whole universeof stations.We suggest that the inlet pressure to the M&R station not be used as a threshold for subsetselection. A large number of PSNC's and SCE&G's M&R stations serve a small number ofcustomers -as few as three per station. Some ofthose small stations have inlet pressures as high as800 psi and would be included anysubset based on inlet pressure.Under the Proposal, EPA is replacing the term "custody transfer city gate station" with the termTransmission-distribution (TD) transfer station". This replacement will sweep in many morestations into the resource-intensive on site leaksurvey requirement than appear to be coveredunder the current rule. Survey data from largerstations should be sufficient to develop anemission factor that can be applied to smaller stations. We urge EPA to impose the leak surveyrequirement only on TD Stations with a design rate of 4 million standard cubic feet per hour(scf/hr). This level will focus the leak surveys on a manageable number of stations.I. New Definition of Stations Subject to Annual Leak Surveys: BAMM Essential to Deal withRetroactive Application to 2011While [COMMENTER] appreciates EPA’s effort to provide clear definitions of what is or is notsubject to the annual component leak surveys, weare very concerned about the dramatic shift inthe type and number of stations that would be subject to the annual leak survey requirement underthe Proposal. We are further concerned that thesenew requirements would apply retroactively tothe beginning of 2011, even though the Technical Revisions are not expected to be issued in finalform until December 2011. Obviously, natural gaslocal distribution companies (LDCs) have hadto make their best guess this year regarding which stations they should leak survey under theexisting Subpart W rule, and in December 2011 they will not be able to turn the clock back toJanuary 2011 and re-do their Subpart W leak survey program. We understand that the agency issuggesting that LDCs will be allowed to dealwith this dilemma by submitting the leak surveysAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencethey have conducted and/or apply an emissionfactor to a count of stations under the BestAvailable Monitoring Methods (BAMM) provisions. See 76 Fed. Reg. at 56,032. It will beimportant to make this clearin the final rule and preamble.25.Clarified definitionsfor parametersapplicable to EquationW-30A and EquationW-30B.Equation W-30:As [COMMENTER] and others have requested, EPA has proposed to clarifythe summation operator in Equation W-30 to makeit mathematically correct, and we appreciatethis correction. 76 Fed. Reg. at 56,032. The agency has also proposed several revisions to use thenew terms “transmission-distribution transferstations” and “metering-regulating stations.”[COMMENTER] supports these revisions. However, Equation W-30 is still confusing andrequires additional revisions.First, there appears to be a conflicting provisions in the definition of Tpin W-30. The last twosentences are confusing. We suggest revising the text to say:“If multiple leak detection surveys are conducted at a facility or TD station, assume that thecomponent found to be leaking has been leaking since the previous survey (if not found in theprevious survey)or the beginning of the entire calendar year (if it was found in the previoussurvey).For the last leak detection survey inthe calendar year, assume that all leakingcomponents continue to leak until the end of the calendar year.”Second, a typographical error appears in the proposed revision to Equation W-30, where thesubscript “s” was omitted from EF. The definitionfor EF was not amended in the proposed rule,so the definition for EF is found in the November 2010 final rule version of Equation W-30 –where the term is listed as EFs. This should be corrected to avoid confusion.Third, Equation W-30 is also confusing because the definition of Es,iin Equation W-30 isdifferent from the definition for Es,iin W-32 even though they represent the same thing. To makeit less confusing, the definition of Es,iin Equation W-30 should be changed to match thedefinition in Equation W-32 which says “Annualvolumetric GHG i emissions, CO2 or CH4 atstandard conditions fromallequipment leak sources atallabove grade T-D transfer stations”.At least 3individuals.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceSection 98.232(i):The proposed amendments to 98.232(i) would change the numbering of thedistribution emission sources and inadvertentlyomit pipeline main equipment leaks from98.232(i). In the November 2010 final rule, section 98.232.(i)(4) listed “pipeline main equipmentleaks”. In the September 2011 Proposal, EPA proposes to revise section 98.232(i)(4) to include“equipment leaks from vaults at below grade metering-regulating stations” but the agencyproposes no further edits to the list. There are no proposed revisions to the first paragraph insection 98.233(r), which references section 98.232(i).As a result, the list in 98.233(r) will need tobe revised to reflect these proposed changes.Leak Detection and Leaker Emission FactorsAlthough EPA has proposed revisions to Equation W-30 in 98.233.q, [COMMENTER] still feelsit is difficult to determine what is being calculated in W-30. Is equation W-30, the sum ofemissions from each component type (ie Es,iis emissions from just connectors) from all stations?Or is it the sum of emissions from all components (ie the sum of emissions from connectors,block valves, control valves, pressure relief valves, orifice meters, regulators AND open-endedlines) from all transmission-distribution stations?It is confusing because of the use of the termscomponent and equipment leak source. Componentis defined in the rule, but equipment leaksource is not. EPA seems to be using these terms interchangeably and they seem to mean thesame thing. For example, the term component is used both in Tpand in equation W-31 definitionof Counts whereas equipment leak source isused in the definition of x and Es,iin equationW-30.In addition, although EPA amended the definition of x in equation W-30, it is still confusing. Thedefinition of x in Equation W-30 should more closely match the language for Es,iin equation W32. Some confusion could be eliminated if the definition of x was changed to “total number ofequipment leak sources, at all above ground stations”. Or the definition of x in W-30 could bechanged to say “total number of each component type”, not equipment leak source, since the termcomponent is used in Tables W-2 through W-7.CommentSubmissionWhen EPA revised Equation W-30 the subscript “s” was omitted from EF. The definition for EFAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencewas not amended in the proposed rule, so the definition for EF is found in the final rule and it islisted as EFs.§98.233(q) includes different default values in the definition of GHGithat follows Equation W30. Section (u)(2) should be referenced rather than introducing different defaults.CommentSubmission26.Clarified text inLeak Detection and Leaker Emission FactorsAt least 1Comment98.233 (q) and (r) byindividual.Submissionconsistently usingAlthough EPA has proposed revisions to Equation W-30 in 98.233.q, NMGC still feels it isterms such asdifficult to determine what is being calculated inW-30. Is equation W-30, the sum of emissions“component type”.from each component type (ie Es,iis emissions from just connectors) from all stations? Or is it thesum of emissions from all components (ie the sum of emissions from connectors, block valves,control valves, pressure relief valves, orifice meters, regulators AND open-ended lines) from alltransmission-distribution stations? It is confusing because of the use of the terms component andequipment leak source. Component is defined inthe rule, but equipment leak source is not. EPAseems to be using these terms interchangeably and they seem to mean the same thing. Forexample, the term component is used both in Tpand in equation W-31 definition of Countswhereas equipment leak source is used in the definition of x and Es,iin equation W-30. Inaddition, although EPA amended the definition of x in equation W-30, it is still confusing. Thedefinition of x in Equation W-30 should more closely match the language for Es,iin equation W32. Some confusion could be eliminated if the definition of x was changed to “total number ofequipment leak sources, at all above ground stations”. Or the definition of x in W-30 could bechanged to say “total number of each component type”, not equipment leak source, since the termcomponent is used in Tables W-2 through W-7.When EPA revised Equation W-30 the subscript “s” was omitted from EF. The definition for EFwas not amended in the proposed rule, so the definition for EF is found in the final rule and it islisted as EFs.Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference27.Modified theintroductory paragraph98.233(r) regardingpopulation count andemission factors,based on changes in98.232(i)The proposed amendments to 98.232.(i) changes the numbering of the distribution emissionsources and ends up omitting pipeline main equipment leaks from 98.232(i). In the November2010 final rule 98.232.i.4 was “pipeline main equipment leaks”. In the September 2011 revision,98.232.i.4 is listed as “equipment leaks from vaults at below grade metering-regulating stations”with no further edits to the list. The first paragraph in section 98.233.r was not amended andreferences 98.232.(i) so the list in 98.233.r will need to be revised to reflect these proposedchanges.At least 1individual.CommentSubmission28.Clarified that “Counts”in Equation W-31 isthe number ofmeter/regulator runsfor the natural gasdistribution industrysegment.Population Count and Emission FactorsIn Equation W-31, the revised definition for EFsin the proposed rule refers to an “EF formeter/regulating runs at above grade metering-regulating stations”. Did EPA intend for theemission factor to be for meter/regulator runs?NMGC’s understanding is we are using W-31 tocalculate emissions from all above grade metering-regulating stations (including above grade TDtransfer stations) using anEF generated from Equation W-32.The proposed rule revises 98.233.r.6.ii, to calculate emissions from all above grade meteringregulating stations (including above grade T-D transfer stations) by applying the EF calculated inW-32 and the total count of meter/regulator runsat all above grade metering-regulating stations(inclusive of T-D transfer stations) to Equation W-31. Does this mean we need to count allmeter/regulator runs at all metering-regulating stations and use this count as the Counts forequation W-31? A count of meter/regulator runs atall metering-regulating stations would be verytime consuming and costly to do. NMGC would haveto visit close to 1,000 stations to obtain thiscount and it would negate thereduced burden EPA included in the final rule of applying acompany specific emission factor to a larger set ofstations that do not need to be surveyed forleaks. Instead, Counts for calculating emission from all above grade metering-regulating stations(including above grade T-D transfer stations)should be the total countof metering-regulatingstations (including T-D transfer stations).In the proposed rule EPA uses a new term, meter/regulator run which isnot defined. Does thismean all meter runs and all regulator runs needto be counted at each transmission-distributionAt least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencetransfer station where a leak survey is conducted? It should mean count meter and/or regulatorssince a meter can be on a regulator run. A meter on a regulator is just one run not two.29.Clarified that reportersDefault Emission Factor for MR Stations at Companies with No TD Stations: A related questionAt least 1Commentwithout T-D transferarises for a few companies that have no TD stations within the meaning of the Proposed Rule.individual.Submissionstation must onlySuch companies will not have the option of leak surveying TD stations to develop a companyreport a count ofspecific emission factor per metering-regulating run for their MR stations. The rule does notabove grade metering-describe what these companies should do. A reasonable solution for this situation is to amend theregulating stations.rule to allow such companies to use the same default emission factor for both above-ground andbelow-ground MR stations, based on inlet pressure. The equipment is essentially the same. Theonly difference is whether it is situated above or below ground.30.Clarified Equation W32 for estimating anemission factor for ameter/regulator run atabove grade meterregulating.Additional Corrections for W-32 and Section 98.233(r):EPA states in the preamble that the agency isproposing to eliminate the summation operator fromEquation W-32. See 76 Fed. Reg. at 56.033. [COMMENTER] supports this change. However, itappears that the agency inadvertently failed to remove this summation operator from Equation W32 in the proposed rule. See 76 Fed. Reg. at 56,045.In this case, it appears the preamble is correctbut the proposed rule is not. [COMMENTER] requests that EPA remove the summation operatorfrom Equation W-32 in section 98.,233(r), as the agency apparently intended. Our members haveattempted to run calculations using the revised equations in the proposed rule, and they havefound this equation is still confusing. Eliminating the summation operator will help remove thatconfusion.At least 1individual.CommentSubmission31.Modified parameter‘EF’ under EquationW-32.Additional Corrections for W-32 and Section 98.233(r):Further, in the proposed amendments, EF from the equation is listed as EFiwhen it is defined.The subscript i is either omitted from the equation or added unnecessarily in the definition for EF.At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference32.Clarified that belowBelow Grade TD Stations: The proposed rule is not clear regarding how and whether to calculateAt least 1Commentgrade T-D transferemissions separately for below grade TD transferstations and below grade metering-regulatingindividual.Submissionstations can use thestations. EPA does not provide an emission factor in Table W-7 for below grade TD transferemission factors forstations for calculating emissions in 98.233(r),although EPA does requireemissions from belowbelow grade metering-grade TD transfer stations to be reported separately under the proposed amendment toregulating stations.98.236(c)(16)(.xvi). Conversely, in98.233(r)(6)(i), below grade TD transfer stations are includedwith below grade metering-regulating stations suggesting they are to be calculated together andnot separately. If EPA does want emissions from below grade TD transfer station to be calculatedseparately from metering-regulating stations, [COMMENTER] suggests using the same emissionfactor for both below grade TD transfer stations and below grade metering-regulating stations.33.Clarified paragraphRevision:Under 98.233(u), EPA replaced field with sub-basin category. EPA clarified that theAt least 1Comment98.233(u)(2)(i) tomole fraction of GHGs in the natural gas is determined by engineering estimate based on bestindividual.Submissionapply to a sub-basin oravailable data unless otherwise specified. EPA alsoclarified that if you have a continuous gasfacility levelcomposition analyzer, you must use an annual average of the values for determining the moledepending on thefraction. Otherwise, an annual average of the available sample analyses for the sub-basin categoryemission source.is used. EPA has also clarified the CH4 and CO2compositions that should be used for the otherindustry sectors.Comment:Several of the reporting categories that donot require reporting on a sub-basin basisdirect you to 98.233(u)(2)(i) for GHGicompositional analysis. EPA revised 98.233(u) to addressissues with determining the appropriate gas composition. For production operations, EPAaddressed the gas composition in terms of the sub-basin approach, as shown below. However,there is an inconsistency between 98.233(u)(2) and 98.233(u)(2)(i). 98.233(u)(2) refers to theaverage mole fraction for each sub-basin categoryor facility; while 98.233(u)(2)(i) requires theuse of available analyses in each sub-basin category. The regulatory text is shown below:(2) For Equation W–35 of this section, the mole fraction, Mi, shall be the annual average molefractionfor each sub-basin category or facility, as specified in paragraphs (u)(2)(i) through (vii)Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceof this section.(i)GHG mole fraction in produced natural gasfor onshore petroleum and natural gasproductionfacilities. If you have a continuous gas composition analyzer for producednatural gas, you must use an annual average of these values for determining the molefraction. If you do not have a continuous gas composition analyzer, then you mustuse an annual average gas composition based on available analysesin each of thesub-basin categories.[COMMENTER] requests that 98.233(u)(2)(i) allow for determining average gas compositionanalysis on either a facility (basin) basis or sub-basin basis, whichever is more appropriate for thespecific emission source category.34.Clarified paragraphRevision:EPA added a time term to equation W-1 toaccount for the duration the device isAt least 1Comment98.233(v) along withoperational for the reporting year. T is defined as“Total number of hours in the operating year theindividual.SubmissionEquation W-36, W-37,devices were operational.”and W-38 andassociated parametersComment:The term “T” should refer to an estimatedaverage annual time for all the devices orbased on changes inallow the use of 8760 hours. An estimate of the time is consistent with the preamble languageEquation W-1.stating “EPA is also proposing to amend Equation W-1 to include a parameter ‘T’ that estimatesthe total number of hours the devices were operational” (emphasis added).Further for this equation, the term “Masss,i”, does not need the subscript “s”, and the definitiondoes not need “at standard conditions” as massdoes not change based on temperature andpressure. [COMMENTER] also requests the term Masss,ibe revised to “mass per type of device”for the different pneumatic device types.The term GHGirefers to “onshore petroleum and natural gas production facilities” and referencesparagraph (u)(2)(i), which is defined as “sub-basin”. However, to be consistent with this equationand the methodology for compiling pneumatic device counts, GHGishould be representative ofAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceall the wells in the basin with a particular devicetype and not aligned with a sub-basin. Revisionsto 98.233(u)(2)(i) to address this are provided in comment W.33.35.Modification ofparameter ‘ɳ’ underEquation W-39A andEquation W-39B.Revision:EPA revised Equation W-39 to account for CO2 present in the combusted gas, to applya combustion efficiency, and to separately quantify CH4 emissions from combustion.Comment:For determining the combustion efficiency,η, [COMMENTER] supports the use ofengineering estimate. In addition, [COMMENTER] requests the option of using a combustionefficiency of 99.5%, as referenced in the footnotes of AP-42 Tables 3.2-1, 3.2-1, and 3.2-2.Other issues with §98.233(z):•For CO2 and CH4, the August 4 amendments still require the use of “latest gas analysisfor the field” and the issue of referencing§98.3 for the meter calibration if a meter isused. [COMMENTER] restates its concerns thatthe use of field analysis is inappropriateand that the reference to §98.3 was notintentional. [COMMENTER] recognizes thatthese issues addressed in theAugust19 amendments. [COMMENTER] reserves the rightto comment on the September 9 amendments separately.•Also, Equations 39 A&B are shown in actualvolume terms in both the August 4 and theSeptember 9 amendments. As discussed above, [COMMENTER] requests restating theseequations in terms of industry standardconditions (60 oF and 14.7 psia).At least 1individual.CommentSubmission36.Clarified paragraphRevision:EPA has added clarifications on the requirements for combustion emissions underAt least 1Comment98.233(z)(1)(i).98.233(z). Natural gas that does not meet the definition of “pipeline quality” is required to use thesame approach as used for the combustion of process vent gas or field gas. EPA has removed therequirement that a flow meter must be used if available.Comments:•A conversion term in Eq. W-40is 1×103, but the term in the definition is 1×10-3.individual.SubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference•In 98.233(z)(1)(i), the first sentence should be corrected to read “...or a blend containingone or more fuels...” instead of “...or a blend containing one more fuels...”.•98.233(z)(2)(ii) is an example of a non-sub-basin reporting category directing you to98.233(u)(2)(i) which requires sub-basin composition analysis. (See comment W.34).•In 98.233(z)(2)(i), EPA has added that you may use company records to determine thevolume of fuel combusted in the unit during the reporting year. [COMMENTER] fullysupports this revision.37.Addition of paragraph98.233(z)(4) oninternal combustionunits not related to acompressor that have arated heat duty below1 mmBtu/hr.On page 56034 of the preamble EPA solicits comments as to why emissions from specificinternal combustion related equipment should not bereported, including the size of the equipmentthat should be excluded along with supporting data.Specifically, EPA is seeking comments on the following:- “...whether a 1 MMBtu/hr equipment threshold for internal combustion engines that are notdriven by natural gas is reasonable.”- “...combustion-related emissions at compressors should not be excluded from reporting,regardless of size, and where EPA can find reliable estimates of natural gas consumption.”- “... why emissions from specific internal combustion related equipment should not be reported,including the size of the equipment that should be excluded alongwith supporting data.”[COMMENTER] Response:For the onshore petroleum and natural gas production segment, the current rule exempts externalcombustion equipment with a rated heat capacity < 5 MMBtu/hr from reporting GHG emissionsregardless of fuel type.[Footnote 4: See 40 C.F.R. § 98.233(z)(3)] The rule simply requiresreporters to report the type and number of each external fuel combustion unit. [COMMENTER]At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencehas welcomed this exemption in the final rule as a means to reducing the reporting burdenassociated with the small quantity ofemissions associated with these sources.[COMMENTER] has noted further that internal combustion equipment with a similar capacity of< 5 MMBtu/hr, regardless of fuel type, should belikewise exempted. The magnitude of emissionsfrom the combustion of internal combustion devices of similar capacity would be no differentthan for the exempted external combustion devices.Although [COMMENTER] appreciatesEPA’s consideration of providing a limited exemption forreporting GHG emissions from small internal combustion engines not fueled with natural gas,[COMMENTER] continues to insist that there is no justification for separate exemptionthresholds for internal and external combustionequipment, no justification for limiting such anexemption to engines not fueled by natural gas, and that all combustion equipment, both internaland external, integral to production operations witha rated capacity of < 5 MMBtu/hr should beuniformly exempted from emissions reporting regardless of fuel type.The reporting burden that EPA found not to be justified for small external combustion devicesremains unjustified for small internal combustion devices. [COMMENTER] recommends thatalong with such an exemption, reporters wouldsimply report the type and number of internalcombustion units, regardless of fuel type, which are integral to production operations, in each ofthe following specified size categories: (a) those that are less than or equal to 125hp(<1MMBtu/hr); (b) those that are over 125hp but less than or equal to 375hp (1-3MMBtu/hr); and(c) those that are over 375hp but less than or equal to 625hp (3-5 MMBtu/hr).This is consistentwith and provides more detailed information than the approach for the excluded externalcombustion devices, and would contribute to reducing the reporting burden. This information willenable EPA to estimate the natural gas consumption by these internal combustion engines andthus provide EPA with needed data for future policy development.At the same time, [COMMENTER] wants to reiterate here that the internal combustion enginesAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceaddressed by this rule should be limited to those that are “integral to the extraction, processing, ormovement of oil or natural gas”, including compressors. This would not include some of thetypes of engines referenced in the first paragraph on Page 56034 of the preamble to theSeptember 9, 2011 proposed rule, and which are already exempt from emissions reporting basedon the promulgated Subpart W requirements.38.Modification ofparagraph98.234(a)(1) to includeexception for usingmethods outlined inparagraph98.234(a)(2).On Page 56034 of the Federal Register preamble, EPA explains that the language in 98.234(a)(2)is being amended to state that Method 21 compliant instruments may be used to monitorinaccessible emission sources. [COMMENTER] supports this change as it does increase theflexibility in monitoring requirements and reduces the burden on industry without compromisingdata quality. However, the proposed rule text in98.234(a)(1) and (2) is confusing. For example,the last sentence in 98.234(a)(1) states that: “An optical gas imaging instrument must be used forall sources types that are inaccessible and cannotbe monitored without elevating the monitoringpersonnel more than 2 meters above a support surface.” Then, the last sentence of 98.234(a)(2)seems to allow the owner/operator to use the alternative leak detection devices as described inparagraph (a)(1) or (a)(2) of thissection, which includes Method 21.Assuming the intent discussed in the preambleis correctly understood, [COMMENTER] suggeststhat EPA clarify in both 98.234(a)(1) and (a)(2) that a Method 21 compliant instrument may beused to monitor inaccessible emission sources thatare subject to the monitoring requirements.At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference39.Clarified in 98.234 (c)that if a calibrated bagis used, the bagopening must besufficient size toencompass the entireemissions volume andthe emissions must bebelow the maximumallowable temperatureas specified by the bagmanufacturer.(c) Use calibrated bags (also known as ventbags) only where the emissions are at nearatmospheric pressures [add: and below the maximum temperature specified by the vent bagmanufacturer] such that [delete: it] [add: the bag] issafe to handle[add: .] [delete: and can captureall the emissions, below the maximum temperature specified by the vent bag manufacturer, and][add: The bag must be of sufficient size that] the entire emissions volume can be encompassed formeasurement.(1) Hold the bag in place enclosing the emissions source to capture the entire emissions andrecord the time required for completely filling thebag. If the bag inflates in less than one second,assume one second inflation time.(2) Perform three measurements of the time required to fill the bag, report the emissions as theaverage of the three readings.(3) Estimate natural gas volumetric emissions atstandard conditions using calculations in§98.233(t).(4) Estimate CH4and CO2volumetric and mass emissions from volumetric natural gas emissionsusing the calculations in §98.233(u) and (v).At least 2individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceRevision:EPA added clarification to the requirements for using a calibrated bag that thetemperature of the source to be measured must be below the maximum temperature specified bythe manufacturer and that the bag must be ofsufficient size that the entire volume can beencompassed for measurement.Comment:[COMMENTER] requests clarification on EPA’sintent in stating “the bag must be ofsufficient size that the entire volume can beencompassed for measurement.” This could beinterpreted to mean that the bag must fit over the entire source being measured. Alternatively, thiscould be interpreted to mean that the bag mustbe sized to capture the venting volume within aspecific time, recognizing, however, that the calibrated bag cannot measure the entire volume.40.Clarified that theunique ID is notrequired for onshoreproduction emissionsources throughout98.236(c).Unique name ID for specified unitsEPA added requirements to report a unique nameor ID number for each AGR unit, each glycoldehydrator, each blowdown vent stack, each wellhead gas-liquid separator, each flare stack, EORinjection pump blowdowns, and each transmission storage tank.[COMMENTER] Response:[COMMENTER]’s member companies insist stronglythat the requirements to develop and reportcertain Subpart W affected equipment through the use of unique identifier information at theindividual equipment level:•were not contemplated or proposed in previous proposals,•have not been subject to commentpreviously, and are unnecessarily onerous,•add substantial costs that were not analyzed nor disclosed in the economic impactanalysis,•do not deliver benefits commensurate with the costs, andAt least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference•are contrary to the original scope and intent of the Greenhouse Gas Reporting Program(GHGRP) and its varying provisions for the different subparts as applicable to specificsectors.This is particularly an issue for wellhead gas-liquid separators with oil throughput greater than orequal to 10 bbls per day. For this source type, EPA has added the requirement to “report thefollowing by sub-basin category, unless otherwisespecified” (emphasis added). 98.236(c)(8) goeson to add reporting requirementsunder paragraphs (J), (K), (L), and (M) that are specified foreach separator and not the aggregate of separators as in the existing rule language. Thesereporting requirements are contrary to EPA’s previously stated goal of their intent to “reducereporting burden.” The introduction of these new reporting requirements for gas-liquid separators,which have no impact on the current emissionsinputs or data quality, under the heading of“Technical Revisions” is clearly contradictory to industry’s efforts to work with EPA to completean accurate GHG inventory within a manageable reporting burden and resources.The entire concept of basin level reporting foronshore petroleum and natural gas production wasjustified by EPA through its desire to achieveadequate coverage ofthe onshore production sectorand its economic impact analysis and the conceptof reducing burden by handling the vast numberof sources as grouped source types rather than discrete emission sources. EPA should not includeor imply individual tracking and reporting for separators that are currently reported as total countsor average emissions information. The requirementfor creating unique identifiers for individualseparators is inconsistent withaggregating equipment and emissions within a basin or sub-basinas currently required in the rule. This proposedchange in effect eliminates the benefits fromhandling separators in the production sector atthe sub-basin level, which [COMMENTER]previously supported, and fundamentallychanges [COMMENTER]’s acceptance of thisapproach.For separators, the throughput, existence, and site-specific functionality (wells they service) canvary or change greatly depending on production scenariosthroughout the year. Some sites haveAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencemultiple separators that may change or be useddifferently throughout the year, so assigning aunique number on a specific separator and tracking for a whole year does not add clarity or value.[COMMENTER] and its members strongly urge thatEPA reconsider its proposal and remove thisrequirement upon promulgation.For the other equipment types that EPA is proposing to require assigning a unique name or IDnumber (AGR units, glycol dehydrator, blowdown vent stacks, flare stacks, EOR injection pumpblowdowns, and transmission storage tanks), the current level of reporting already relies onindividual component counts and equipment inventories that apply to EPA specified calculations.Creating unique equipment identifiers neither adds to the level of accuracy of calculatedemissions, nor does it provide information that isnot already available through the currentlyreported individual equipment counts and reported CO2 and CH4 emissions totals that are alreadypart of the GHGRP.[COMMENTER] further contends that the identifier data requested by EPA will not be usable atthe individual equipment level due to the dynamic nature of the sector and the fact that theidentifiers may be tied to well names or locations and hence be different every year due tofrequent equipment movement, change-outs and replacements that routinely occur at Oil and Gaswell sites. For example, flaring during drilling orcompletion operations uses either portable flaresor open-ended pipe which is moved to new drilling/completion operations. A unique name or IDfor the “flare” is meaningless in this situation.This requirement would lead to the expenditureof unnecessary time and resources to createidentifiers, which serve no other purpose than tospecifically identify equipment that is alreadycalled out and accounted for within the current GHGRP process.41.Separated reportingrequirements forCalculationRevision:For Well Venting for Liquids Unloading, EPA is proposing a vent measurement foreach unique well tubing diameter grouping and pressure grouping in each sub-basin category.Pressure groupings are defined in 98.238 as:≤25 psig; 25-60 psig; 60-110 psig, 110-200 psig;At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceMethodology 1 andand > 200 psig. Tubing diameter groupings are defined in 98.238 as≤1 inch; 1-2 inches; and≥2Calculationinches. The average flow rate is calculated for each unique tubing diameter grouping and pressureMethodology 2 and 3grouping in each sub-basin category by dividing the recorded total flow by the recorded time for ain paragraphsingle liquid unloading with venting to the atmosphere. The revisions also state that for a new98.236(c)(5).producing sub-basin category, an average flow rate is calculated beginning in the first year ofproduction.Comment:EPA has modified the terms used in Equation W-7 to address the groupings by tubingdiameter and pressure. However, the emissions resulting from Equation W-7 are inconsistent withthe reporting requirements under 98.236(c)(5). It appears, though it is not explicitly stated, thatEquation W-7 is intended to result in emissions summed for the sub-basin, while the reportingrequirements are for each well tubing diameter and pressure grouping. [COMMENTER]interprets Equation W-7 to result in emissions aggregated for the sub-basin and requests that thereporting requirements be modified to be consistent.The reporting requirements are further confused by combining the requirements forMethodologies 1, 2, and 3 all under the sameparagraph of 98.236(c)(5). [COMMENTER]requests that EPA specify separate reporting requirements for Methodology 1.Methodology 1 indicates that the pressure groupings apply across each of the sub-basin category(conventional and unconventional)and tubing grouping. [COMMENTER] has provided separatecomments specifically addressing the pressure groupings under comment W.56.As indicated in comment W.58, [COMMENTER] proposes the use of two tubing diametergroupings, rather than the three proposed by EPA. In addition, while the pressure and tubinggroupings only apply to Methodology 1, the reporting requirements under 98.236(c)(5) requirereporting emissions for each tubing diameter and pressure grouping for Methodologies 2 and 3 aswell. [COMMENTER] requests that EPA remove the reporting requirements by pressuregrouping for Methodologies 2 and 3 since these groupings do not apply to calculationAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceMethodologies 2 and 3.42.Modified paragraphRevision:EPA revised Equation W-10, but not as [COMMENTER] had requested in our July 29,At least 1Comment98.236(c)(6)(i) to2011 correspondence to EPA.individual.Submissioninclude reference ofsub-basin and wellComment:In an e-mail provided to EPA on July 29,2011, [COMMENTER] provided regulatorytype for hydraulicrevisions to Equation W-10. [COMMENTER] proposedto remove the subtraction of the SG termfracturing and toand define the “flow-back volume” term in Equation W-10 by limiting it only to the time spaninclude reportingduring which gas is actually vented tothe atmosphere or flared. The SGpterm should be removedrequirements forand FRM should be revised to reflect venting to the atmosphere. SGpis not needed since T isEquation W-10B.defined as the hours vented. If a well is venting, then it is not recovering to sales.These proposed revisions add clarity, simplify the calculation, and reflect the emissionscharacteristics of flow-back operations. Without the removal of the SG term, Equation W-10 hasthe potential to either lead to the calculation ofa negative emissions value, or compare emissionsvalues vented to the atmosphere to sales valuesthat are produced against the back-pressure of agathering or sales pipeline; these are twocompletely different operating scenarios.[COMMENTER]’s proposed mark-ups to incorporate the changes for 98.233(g) are provided inSection 4 of these comments.EPA has added language defining the number of measurements required based on the number ofworkovers/completions. [COMMENTER] interprets this requirement to apply to the sub-basin.Clarification is needed that the number of measurements required is relative to a sub-basin orbasin (facility) and well type combination andnot total number of completions/workovers.In addition, [COMMENTER] requests the addition of a new equation that sums availablemeasurements and eliminates the need for normalizing and tracking cumulative venting time.Some companies are planning to measure the venting associated with gas well completion andAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceworkovers with hydraulic fracturing. Equation W-10 does not allow the use the actualmeasurements. [COMMENTER] has included this new equation in the proposed revisionsprovided in Section 4 below.43.Modification ofparagraph98.236(c)(7) regardingdata reportingrequirements forblowdown vent stacks.6. Reporting Requirements: §98.236(c)(7)(i) reporting for blowdown vents should berevised. In addition, to complement the Proposed Rule and the September 9 proposedrevisions, EPA will need to revise the recently adopted criteria in Subpart A Table A-7regarding data elements where reporting is deferred until 2015.§98.236(c)(7)(i) reporting for blowdowns includesthe number of blowdowns "per unique volumetype". As indicated by [COMMENTER] recommendations (see EPA-HQ-OAR-2011-0512­0013), an alternative equation is needed (i.e., summing the annual blowdown volumes by event).With that approach, only the total volume should be reported. “Unique volume type” is amisnomer for determining compressor station blowdown emissions because most events will beassociated with a unique circumstance and repetitive blowdown of the same volume is not thenorm. The reporting section for blowdown vents should be revised to include reporting associatedwith the current equation (which is revised toEquation W-14A in the September 9 proposedrevisions) and separate criteria for blowdown emissions calculated by summing individual events(i.e., see approach associated with Equation W-14B in the September 9 proposed technicalcorrections). [COMMENTER] will provide additional details in October comments on the secondproposal.At least 1individual.CommentSubmission44.Removal ofrequirement to reportper wellhead separatoror storage tank in98.236 (c)(8)(i)(J)through (L).Unique name ID for specified unitsEPA added requirements to report a unique nameor ID number for each AGR unit, each glycoldehydrator, each blowdown vent stack, each wellhead gas-liquid separator, each flare stack, EORinjection pump blowdowns, and each transmission storage tank.[COMMENTER] Response:At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference[COMMENTER]’s member companies insist stronglythat the requirements to develop and reportcertain Subpart W affected equipment through the use of unique identifier information at theindividual equipment level:•were not contemplated or proposed in previous proposals,•have not been subject to commentpreviously, and are unnecessarily onerous,•add substantial costs that were not analyzed nor disclosed in the economic impactanalysis,•do not deliver benefits commensurate with the costs, and•are contrary to the original scope and intent of the Greenhouse Gas Reporting Program(GHGRP) and its varying provisions for the different subparts as applicable to specificsectors.This is particularly an issue for wellhead gas-liquid separators with oil throughput greater than orequal to 10 bbls per day. For this source type, EPA has added the requirement to “report thefollowing by sub-basin category, unless otherwisespecified” (emphasis added). 98.236(c)(8) goeson to add reporting requirementsunder paragraphs (J), (K), (L), and (M) that are specified foreach separator and not the aggregate of separators as in the existing rule language. Thesereporting requirements are contrary to EPA’s previously stated goal of their intent to “reducereporting burden.” The introduction of these new reporting requirements for gas-liquid separators,which have no impact on the current emissionsinputs or data quality, under the heading of“Technical Revisions” is clearly contradictory to industry’s efforts to work with EPA to completean accurate GHG inventory within a manageable reporting burden and resources.The entire concept of basin level reporting foronshore petroleum and natural gas production wasjustified by EPA through its desire to achieveadequate coverage ofthe onshore production sectorand its economic impact analysis and the conceptof reducing burden by handling the vast numberof sources as grouped source types rather than discrete emission sources. EPA should not includeAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceor imply individual tracking and reporting for separators that are currently reported as total countsor average emissions information. The requirementfor creating unique identifiers for individualseparators is inconsistent withaggregating equipment and emissions within a basin or sub-basinas currently required in the rule. This proposedchange in effect eliminates the benefits fromhandling separators in the production sector atthe sub-basin level, which [COMMENTER]previously supported, and fundamentallychanges [COMMENTER]’s acceptance of thisapproach.For separators, the throughput, existence, and site-specific functionality (wells they service) canvary or change greatly depending on production scenariosthroughout the year. Some sites havemultiple separators that may change or be useddifferently throughout the year, so assigning aunique number on a specific separator and tracking for a whole year does not add clarity or value.[COMMENTER] and its members strongly urge thatEPA reconsider its proposal and remove thisrequirement upon promulgation.For the other equipment types that EPA is proposing to require assigning a unique name or IDnumber (AGR units, glycol dehydrator, blowdown vent stacks, flare stacks, EOR injection pumpblowdowns, and transmission storage tanks), the current level of reporting already relies onindividual component counts and equipment inventories that apply to EPA specified calculations.Creating unique equipment identifiers neither adds to the level of accuracy of calculatedemissions, nor does it provide information that isnot already available through the currentlyreported individual equipment counts and reported CO2 and CH4 emissions totals that are alreadypart of the GHGRP.[COMMENTER] further contends that the identifier data requested by EPA will not be usable atthe individual equipment level due to the dynamic nature of the sector and the fact that theidentifiers may be tied to well names or locations and hence be different every year due tofrequent equipment movement, change-outs and replacements that routinely occur at Oil and Gaswell sites. For example, flaring during drilling orcompletion operations uses either portable flaresAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceor open-ended pipe which is moved to new drilling/completion operations. A unique name or IDfor the “flare” is meaningless in this situation.This requirement would lead to the expenditureof unnecessary time and resources to createidentifiers, which serve no other purpose than tospecifically identify equipment that is alreadycalled out and accounted for within the current GHGRP process.45.Clarified the referenceG. Well testing venting and flaringAt least 1Commentin 98.236(c)(10)On page 56031 of the September 9,2011 preamble, EPA is addressingwell testing and ventingindividual.Submissionbecause a newand flaring. Among other things, EPA is considering, but has not yet proposed, using theequation was addedproduction rate to estimate the volume of emissions from venting and testing gas wells thatunder 98.233 (l).produce dry gas. EPA is soliciting comments on this suggested provision for gas wells.Commenter Response:Commenter agrees that production rate could be used as an estimate of gas flow rate.46.Clarifications to theRevision:98.236(c)(15)(ii)(b) requires reporting fugitive emissions for each type of majorAt least 1Commentlevel of reportingequipment by sub-basin category. However, Equation W-31, which is the calculation approachindividual.Submissionrequired inapplied for fugitive emissions by population counts isapplied at the facility (i.e. basin) level.98.236(c)(15)(ii)(B).Comment:The reporting requirements should align with the calculation method. The definitionsfor “Count” and “GHGi” Equation W-31 clearly refer to the facility. [COMMENTER] requeststhat the reporting requirements be revised accordingly.47.Addition of rollingaverage reportingrequirement for abovegrade T-D transferstations.Under the Proposal, EPA is replacing the term "custodytransfer city gate station" with the termTransmission-distribution (TD) transfer station". This replacement will sweep in many morestations into the resource-intensive on site leaksurvey requirement than appear to be coveredunder the current rule. Survey data from largerstations should be sufficient to develop anemission factor that can be applied to smaller stations. We urge EPA to impose the leak surveyrequirement only on TD Stations with a design rate of 4 million standard cubic feet per hour(scf/hr). This level will focus the leak surveys on a manageable number of stations.At least 2individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceI. New Definition of Stations Subject to Annual Leak Surveys: BAMM Essential to Deal withRetroactive Application to 2011While [COMMENTER] appreciates EPA’s effort to provide clear definitions of what is or is notsubject to the annual component leak surveys, weare very concerned about the dramatic shift inthe type and number of stations that would be subject to the annual leak survey requirement underthe Proposal. We are further concerned that thesenew requirements would apply retroactively tothe beginning of 2011, even though the Technical Revisions are not expected to be issued in finalform until December 2011. Obviously, natural gaslocal distribution companies (LDCs) have hadto make their best guess this year regarding which stations they should leak survey under theexisting Subpart W rule, and in December 2011 they will not be able to turn the clock back toJanuary 2011 and re-do their Subpart W leak survey program. We understand that the agency issuggesting that LDCs will be allowed to dealwith this dilemma by submitting the leak surveysthey have conducted and/or apply an emissionfactor to a count of stations under the BestAvailable Monitoring Methods (BAMM) provisions. See 76 Fed. Reg. at 56,032. It will beimportant to make this clear inthe final rule and preamble.48.Added separatereporting requirementsfor internalcombustion engineswith a rated heat dutyof above 1 mmBtu/hrand a rated heat dutyof below 1 mmBtu/hr.On page 56034 of the preamble EPA solicits comments as to why emissions from specificinternal combustion related equipment should not bereported, including the size of the equipmentthat should be excluded along with supporting data.Specifically, EPA is seeking comments on the following:- “...whether a 1 MMBtu/hr equipment threshold for internal combustion engines that are notdriven by natural gas is reasonable.”- “...combustion-related emissions at compressors should not be excluded from reporting,regardless of size, and where EPA can find reliable estimates of natural gas consumption.”- “... why emissions from specific internal combustion related equipment should not be reported,At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceincluding the size of the equipment that should be excluded alongwith supporting data.”[COMMENTER] Response:For the onshore petroleum and natural gas production segment, the current rule exempts externalcombustion equipment with a rated heat capacity < 5 MMBtu/hr from reporting GHG emissionsregardless of fuel type.[Footnote 4: See 40 C.F.R. § 98.233(z)(3)] The rule simply requiresreporters to report the type and number of each external fuel combustion unit. [COMMENTER]has welcomed this exemption in the final rule as a means to reducing the reporting burdenassociated with the small quantity ofemissions associated with these sources.[COMMENTER] has noted further that internal combustion equipment with a similar capacity of< 5 MMBtu/hr, regardless of fuel type, should belikewise exempted. The magnitude of emissionsfrom the combustion of internal combustion devices of similar capacity would be no differentthan for the exempted external combustion devices.Although [COMMENTER] appreciatesEPA’s consideration of providing a limited exemption forreporting GHG emissions from small internal combustion engines not fueled with natural gas,[COMMENTER] continues to insist that there is no justification for separate exemptionthresholds for internal and external combustionequipment, no justification for limiting such anexemption to engines not fueled by natural gas, and that all combustion equipment, both internaland external, integral to production operations witha rated capacity of < 5 MMBtu/hr should beuniformly exempted from emissions reporting regardless of fuel type.The reporting burden that EPA found not to be justified for small external combustion devicesremains unjustified for small internal combustion devices. [COMMENTER] recommends thatalong with such an exemption, reporters wouldsimply report the type and number of internalcombustion units, regardless of fuel type, which are integral to production operations, in each ofthe following specified size categories: (a) those that are less than or equal to 125hpAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference(<1MMBtu/hr); (b) those that are over 125hp but less than or equal to 375hp (1-3MMBtu/hr); and(c) those that are over 375hp but less than or equal to 625hp (3-5 MMBtu/hr).This is consistentwith and provides more detailed information than the approach for the excluded externalcombustion devices, and would contribute to reducing the reporting burden. This information willenable EPA to estimate the natural gas consumption by these internal combustion engines andthus provide EPA with needed data for future policy development.At the same time, [COMMENTER] wants to reiterate here that the internal combustion enginesaddressed by this rule should be limited to those that are “integral to the extraction, processing, ormovement of oil or natural gas”, including compressors. This would not include some of thetypes of engines referenced in the first paragraph on Page 56034 of the preamble to theSeptember 9, 2011 proposed rule, and which are already exempt from emissions reporting basedon the promulgated Subpart W requirements.49.Amended paragraphRevision:EPA has added a requirement to report average [COMMENTER] gravity, average gasAt least 1Comment98.236 (e).to oil ratio, and average low pressure separatorpressure for each sub-basin category. On page56034 of the September 9, 2011 preamble EPA contends that this information is already known toreporters and it plans to use these facility sub-basin characteristics to characterize other emissionssources across different sub basins.Comment:This information is not available or appropriate for broader applications to each of thesub-basin categories. For example, dry gas production areas, such as coal-bed methane, will nothave [COMMENTER] gravity or gas tooil ratios to report for a sub-basin.[COMMENTER] interprets this reporting requirement as applicable only to the oil productionsub-basin category proposed for addition by [COMMENTER]. Only this sub-basin category isconsistent with the preamble language, which indicates that this information is readily available.For the oil production sub-basin category, this requirement should only apply to separators withoil throughput greater than or equal to 10 barrels per day, as it is only for these operations whereindividual.SubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencethis information is available. [COMMENTER] alsointerprets the requirement to report the lowpressure separator pressure to refer only to the separator pressure in those instances where theseparator oil composition is sampled and analyzed.50.Modification ofparagraph 98.238, thedefinition of‘Associated with asingle well-pad’.Revision:EPA added a new definition for “associated with a single well-pad”.Comments:EPA needs to clarify what theword “This” is referring to in the beginning of the lastsentence. [COMMENTER] suggests the following revisions to the definition as shown in greenfont:•Associated with a single well-pad meansassociated with the hydrocarbon stream asproduced from one or more wells located on that single well-pad.For all equipmentwith the exception of storage and condensate tanks, theexclusion for theassociationends where the stream from a single well-pad is combined with streams from one or moreadditional single wellpads, where the point ofcombination is located off that single wellpad. This does not includes storage and condensate tanks that are located downstream ofthe point of combination.[COMMENTER] offers the diagrams provided inSection 3, which illustrate [COMMENTER]’sunderstanding of the proposed definition for“associated with a well-pad” and the proposedrevised source category definition for onshore petroleum and natural gas production.[COMMENTER] is providing this information to companies as a tool to guide industry to classifytheir emission sources for data collection and reporting, although we realize that it is toocumbersome to include in regulatory language.At least 1individual.CommentSubmission51.Addition of “meter/Equation W-32 and §98.233(r)(2)(ii):At least 1Commentregulator run”individual.Submissiondefinition.The preamble incorrectly states that the agencyis proposing to amend Equation W-32 to yield anemission factor in cubic feet “per meter to beused in Equation W-31 for above ground meteringregulating stations.” See 76 Fed. Reg. at 56,033. We think you meant to say “per metering­Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceregulating station.” If the emission factor in the Proposal is to apply to a count of meters, wewould have a problem, because the emission factor is supposed to apply to some stations wherethere are no meters. Recall that the proposed term“metering-regulating station” is defined toinclude stations that have (1) a pressure regulator but not a meter; or (2) a meter but not apressure regulator; or (3) both a meter and a regulator. See 76 Fed. Reg. at 56,050. Fortunately,the actual proposed rule language in Equation W-32correctly directs LDCs to count the “[t]otalnumber of meter/regulator runs at all TD transfer stations.” 76 Fed. Reg. at 56,045. Proposedsection 98.233(e(6)(ii) also correctly uses the term “meter/regulator runs.”Define Meter/Regulator Run: [COMMENTER] supports changing the emission factor so that it isbased on a count of meter/regulator runs rather than a count of “meters.” However, we urge EPAto define this new term “meter/regulator run.” There is no definition in the proposed rule. Wesuggest the following definition:“Meter/ regulator run means a series of components used in regulating pressure or meteringnatural gas or both.”52.Modified definition or“Pressure group”under paragraph98.238.Revision:EPA added a new definition for “pressure groupings”:Pressure groupings are defined as follows: less than orequal to 25 psig; greater than 25 psig andless than or equal to 60 psig; greater than 60 psigand less than or equal to 110 psig; greater than110 psig and less than or equal to200 psig; and greater than 200 psig.Comments:•As noted in comment W.13, the pressure groupings only apply to Methodology 1 for theliquids unloading emission source.•Also as noted in comment W.13 above, Methodology 1 indicates that the pressure groupingsapply across each of the sub-basin category(conventional and unconventional) and tubinggrouping. This is inconsistent with previous discussions with EPA, where pressure groupingwere discussed only in the context of conventional wells. [COMMENTER] requests that theregulatory language clarify that pressure groupingsare only applicable to conventional wells.At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference•In discussions with EPA and an e-mail sent on June 22, 2011, [COMMENTER] proposedtwo pressure groupings for Conventional formations based on flowing wellhead pressure.[COMMENTER] requests that the pressure groupings be limited to two pressure groupings asoriginally proposed by the [COMMENTER].Based on the pressure regimes EPA included inthis amendment, the two recommended pressuregroupings would be< 110 psig and > 110psig. Requiring five pressure groupings for three tubing diameter groupings and fourformation types per county is excessive considering the logistics involved with capturingcalibrated metered vent rates. Two pressure groupings will still provide EPA with the desiredrepresentative data and sufficient data granularity for future policy development.[COMMENTER] recognizes that there may be someconcerns regarding the range of the twoproposed pressure groupings and would propose that the pressure of the representative meteredvent rates be within ±10% of the average pressure of the range (ΣP / well count) to address thisissue.•EPA does not define what pressure is to beused for the pressure groupings. [COMMENTER]interprets the pressure groupings to be basedon the surface pressure. As EPA indicated inAppendix D of the Technical Support Document associated with these proposed amendments,reservoir shut-in pressure is not available in the public domain. [COMMENTER] agrees withthis assessment, and as indicated in CommentW.14 reservoir shut-in pressure is not reliablyavailable in operations either.53.Modifications to thedefinition of “Subbasin category” under98.238 and removal ofthe definition of “oilwell” and “gas well”.Revision:EPA added a new definition for “sub-basin category”.Comments:[COMMENTER] requests the following revisions, shown in green font:Sub-basin category, for onshore natural gas production, means a subdivision of a basin into theunique combination of wells with the surface coordinates within the boundaries of an individualcounty and subsurface completion in one or moreof each of the following [add (green): five]At least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference[delete (green): four] formation types: [add (green):oil, conventional gas, shale gas, coal seam, orother tight reservoir rock. The distinction betweenconventional gas and tight gas reservoirs shallbe [delete (green): as] [add (green): designated as:] [delete (green): by 18 C.F.R. 270.305:]conventional with >0.1 millidarcy permeability, and unconventional tight with =0.1 millidarcypermeability. [add (green): Permeability for a reservoir type shall be determined by engineeringestimate.] [delete (green): Unconventional formation types are either shale, coal seam, or othertight reservoir rock.] Wells producing from morethan one [delete (green): unconventional]formation type shall be classified into onlyone type based on the formation with the mostcontribution to production as determined byengineering knowledge. [delete (green):Unconventional wells producing in two or more formation types of “shale and coal seam”, “shaleand other tight”, or “shale, coal seam, and other tight”; are considered shale. In addition,unconventional wells producing in “coal seam and other tight” formations are considered coal.]•[COMMENTER] requests the revisions noted above. Deleting “unconventional” in the thirdsentence clarifies how to distinguish between wells that produce from co-mingledconventional and unconventionalformations (the previous language did not address thissituation). In addition, the last two sentences appear contradictory. [COMMENTER] prefersto assign formation types by the highest contribution to production based on engineeringknowledge.•In the preamble (page 56026 middle column), EPAindicates “In the event that there is morethan one formation, then the reporters woulduse the most specific designation.” This seemsto imply that only one formation type isassigned per county. Whereas the rule languageassigns the formation type by well, with only one designation to each well. [COMMENTER]prefers the approach described inthe preamble and requests additional clarification in the rulelanguage if EPA’s intent is for reporters to assign only one formation type per county. If theintent is for reporters to assign only one formation type per county, then EPA would need toclarify what is meant by “most specific designation”.•The revisions above address [COMMENTER]’s concern that a sub-basin category for oilproduction was not previously defined.Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference54.Clarification to thedefinition of“transmissiondistribution transferstation”EPA is now proposing to replace the term “custody transfer city gate station” with the termTransmission-distribution (TD) transfer station”defined in proposed revised section 98.238 tomean:“a meter-regulating station where a local distribution company takes part or all of the naturalgas from a transmission pipeline and puts it into a distribution pipeline.The term “metering-regulating station” is also defined in revised §98.238. We believe this is theclearer term and should be used consistently instead of “meter-regulating station" as used in theTD station definition above.At least 1individual.CommentSubmission55.Clarification to theRevision:EPA added a new definition for “tubing diameter groupings”:At least 1Commentdefinition of “tubingTubing diameter groupings are defined as follows: less than or equal to 1 inch; greater than 1 inchindividual.Submissiondiameter groupings”.and less than 2 inch; and greaterthan or equal to 2 inch.Comment:[COMMENTER] supports this grouping concept. However, tubing diameters forcompletions are not commonly less than 1 inch. [COMMENTER] suggests that two categories oftubing diameter be used based on the most common tubing sizes used in completions:≤2 3/8”nominal diameter and > 2 3/8” nominal diameter.56.Clarification to theRevision:EPA added a new definition for “well testing venting and flaring”:At least 1Commentdefinition of “wellWell testing venting and flaring means venting and/or flaring of natural gas at the time theindividual.Submissiontesting venting andproduction rate of a well is determinedfor regulatory purposes (i.e., the well testing) through aflaring”.choke (an orifice restriction). If well testing is conducted immediately after well completion orworkover, then it is considered part of well completion or workover.Comment:[COMMENTER] suggests the revisions shown above in green font to make thedefinition technically correct. [COMMENTER] supports the clarification that well testingconducted after a well completion or workover, is considered part of the completion or workover.Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference57.Modification of[COMMENTER] notes that EPA has not proposed revisions to the pneumatic emission factorsAt least 1Commentemission factor infor the production sector. [COMMENTER] had previously pointed out an error in the emissionindividual.SubmissionTable W-1A for Lowfactors provided in Table W-1A. Below, [COMMENTER] provides a corrected derivation forContinuous BleedPneumatic Devicethese emission factors:Vents, HighContinuous BleedPneumatic Device Emission Factor CorrectionPneumatic DeviceVents, Intermittent[COMMENTER] Question (Response Tracker 4844-40)Bleed PneumaticThe derivation provided in the Technical Support Document (TSD) for the high bleed, low bleed,Device Vents, andPneumatic Pumpand intermittent bleed pneumatic device emissionfactors provided in Table W-1A introduces anerror. Footnote 3. U.S. Environmental Protection Agency (EPA). Greenhouse Gas EmissionsReporting from the Petroleum and Natural Gas Indistry, Background Technical SupportDocument, U.S. EPA, Climate Change Division, Washington, DC.<http://www.epa.gov/climatechange/emissions/downloads10/Subpart-W_TSD.pdf>] Thederivation incorrectly divides by the CH4 weight fraction (e.g. D=0.788). The correct values areprovided in the API Compendium (Table 5-15;based on scf/day of natural gas at 60 °F).EPA Response (January 28, 2011): The emission factors in Table W-1A are correct. The emissionfactors in Table 5-15 of the API compendium are Methane (CH4) emission factors, where as theemission factors in Table W-1A are Whole Gas emission factors.[COMMENTER] Follow-up:It appears EPA misunderstood the emission factors they have cited from the API Compendium.Table 5-15 of the 2009 API Compendium provides emission factors for pneumatic devices in twosets of units. The first column cites emission factors from the original reference in the same unitsAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceas the original reference. The original reference for the emission factors of interest is the data setused to develop the emission estimates provided in Volume 12 of the GRI/EPA 1996 study andthe derivation provided in Table B-14 of the API Compendium. [Footnote 4 Shires, T.M. andM.R. Harrison. Methane Emissions from the Natural Gas Industry, Volume 12: PneumaticDevices, Final Report, GRI-94/0257.29 and EPA-600/R-96-080l, Gas Research Institute and U.S.Environmental Protection Agency, June 1996.http://www.epa.gov/gasstar/documents/emissions_report/12_pneumatic.pdf] As shown in bothCompendium Tables 5-15 (Column labeled “Emission Factor, Original Units) and B-14 (Columnlabeled “Bleed Rate (scf/day)), the units are in scf ofgasper device. The emission factors arethen converted to tonnes CH4/device-yr in the far right-hand column of Table 5-15 and thebottom row of Table B-14.The TSD incorrectly labels the emission factorunits as scfd CH4/device and then divides by theCH4 mole% in an attempt to convert the emissionfactor to a total gas basis. This erroneouslyincreases the emission factors. The TSD calculationsshould be corrected to show the following:"High Continuous Bleed Pneumatic Device Vents" Methodology37.9scf/hour/component EF = (705.7 From Compendium Table B-14[scfd CH4/pneumaticdevises, high bleed]) * (B) / (D) / (E)OR37.9scf/hour/component EF = (896 [scfdgasCH4/pneumatic devises, high bleed]) * (B) / (D)/(E)At industry standard conditions of 60 oF, the emission factor is 37.3 scfh/deviceConversions:Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceB: 1.015 = (68+459.67)/(60+459.67) = conversion from 60°F to 68°F[[COMMENTER]suggests removing this conversion and requeststhat the emission factors be provided atindustry standard conditions of 60 oF.]D: 78.8% – production quality of natural gas (%methane), taken from Table B-14 of the 2009API Compendium[This should be shown as 0.788, as used in the equation.]E: 24 hours/dayLow Continuous Bleed Pneumatic Device Vents” Methodology1.41scf/hour/component EF = (26.3 From Compendium Table B-14[scfd CH4/pneumaticdevises, low bleed]) * (B) / (D) / (E)OR1.41scf/hour/component EF = (33.4 [scfdgasCH4/pneumatic devises, low bleed]) * (B) / (D)/(E)At industry standard conditions of 60 oF, the emission factor is 1.39 scfh/deviceConversions:B: 1.015 = (68+459.67)/(60+459.67) = conversion from 60°F to 68°F[[COMMENTER]suggests removing this conversion and requeststhat the emission factors be provided atindustry standard conditions of 60 oF.]D: 78.8% – production quality of natural gas (% methane)[This should be shown as 0.788, asused in the equation.]E: 24 hours/day“Intermittent Bleed Pneumatic Device Vents” MethodologyAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReference13.7scf/hour/component EF = (323From GRI/EPA CH4 Study, Vol. 12, Table 4-6[scfdgasCH4/pneumatic devises, low bleed]) * (B) / (D)/ (E)At industry standard conditions of 60 oF, the emission factor is 13.5 scfh/deviceConversions:B: 1.015 = (68+459.67)/(60+459.67) = conversion from 60°F to 68°F[[COMMENTER]suggests removing this conversion and requeststhat the emission factors be provided atindustry standard conditions of 60 oF.]D: 78.8%–production quality of natural gas (% methane) 44E: 24 hours/dayThe corrected emission factors, derived abovefor industry standard conditions of 60oF and 14.7 psia, are summarized below.- High Continuous Bleed Pneumatic Device Vents= 37.3 scfh/device- Low Continuous Bleed Pneumatic Device Vents= 1.39 scfh/device- Intermittent Bleed Pneumatic Device Vents = 13.5 scfh/device58.Modification ofemission factor inTable W-3 and W-4for Intermittent BleedPneumatic DeviceVentsSeparate emission factors are warranted for high-bleed and intermittent-bleed devices. In TableW-3 and Table W-4 of Subpart W, the same emissionfactor is applied to high continuous bleedpneumatic device vents and intermittent bleed pneumatic device vents. The Subpart W TechnicalSupport Document (TSD) indicates the emission factor is from the GRI Methane Emissions fromthe Natural Gas Industry” study. This study and other reference documents provide differentemission factor "tiers". The Subpart W factor is a “Tier 2” emission factor derived from the “Tier3” continuous and intermittent bleed emission factors (shown in Table 1 below), and theestimated relative populations of each device type. Tier 2 emission factors are appropriate whenpneumatic device counts do not distinguish between continuous bleed and intermittent bleedAt least 1individual.CommentSubmissionAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencedevices, but Subpart W requires separate counts ofcontinuous bleed and intermittent bleeddevices (i.e., Tier 3 activity data). Thus, Tier3 intermittent device emission factors from the GRIstudy would appear more appropriate.Table 1 lists the Tier 3 and Tier 2 emission factors from the GRI study. For intermittent bleeddevices, separate Tier 3 emission factors for turbine valve operators and pneumatic/hydraulicvalve operators could be used or a weighted average Tier 3 intermittent bleed emission factor(i.e., 2.51 scf NG/hr) could be used as shown in Table 1.Table 1. Pneumatic Device Emission Factors for Transmission and StorageEmission Source: Gas-driven continuous bleed pneumatic devicesEmission Factor* Tier: 3Emission Factor* scf NGA/ device-yr: 505,000Emission Factor* scf NGA/ device-hr : 57.7Reference Tier DEmission Source: Turbine valve operator (Intermittent bleed)Emission Factor* Tier: 3Emission Factor* scf NGA/ device-yr: 68,600Emission Factor* scf NGA/ device-hr : 7.84Reference Tier DEmission Source: Pneumatic/hydraulic valve operator (Intermittent)Emission Factor* Tier: 3Emission Factor* scf NGA/ device-yr: 5,710Emission Factor* scf NGA/ device-hr : 0.652Reference Tier DAppendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferenceEmission Source: Intermittent bleed pneumatic deviceEmission Factor* Tier: 3BEmission Factor* scf NGA/ device-yr: 22,000Emission Factor* scf NGA/ device-hr : 2.51Reference Tier DEmission Source: Gas-operated pneumatic devicesEmission Factor* Tier: 2CEmission Factor* scf NGA/ device-yr: 176,000Emission Factor* scf NGA/ device-hr : 20.1Reference Tier D* Emission factors reported to three significant figures for consistency with Subpart W.A. Based on standard temperature of 68°F and standard pressure of 14.73 psiB. Weighted average of Tier 3 emission factors for intermittent bleed devicesC. Weighted average of Tier 3 emission factors for continuous bleed and intermittent bleeddevicesD. Emission factors based on data collected for the 1996 GRI/EPA Study. These emission factorsare also included in the [COMMENTER] GHG Guidelines, API Compendium, GRIGHGCalcTM, and the U.S. Inventory of Greenhouse Gas Emissions and Sinks.In addition, these emission factors are based on a small emissions data set that was collected inthe early 1990’s. Thus, these emission factors may not be representative of pneumatic devicescurrently used in the naturalgas T&S segments and of questionable accuracy when developingemission estimates. This issue is of particularconcern for the intermittent bleed device emissionfactors, which may not reflect integration of current generation “no bleed or low bleed” devices.The emission factor engineering units should be revised. The Proposed Rule units for theemission factors are “scf THC/device-hr.” The emission factor units should be “scf NG/devicehr”Appendix ASummary Of Comments Being Resolved By The TechnicalCorrections, Clarifying and Other Amendments PackageTechnical IssueQuestions Submitted to EPAType andapproximatenumber ofsubmittalsReferencebased on the data used to develop the emission factors. NG (natural gas) is the appropriate basisfor the engineering units and THC (total hydrocarbons) is not appropriate or equivalentnomenclature. For example, analysis on a THC basis would typically be expressed as methaneequivalents for natural gas and provides a different result unless the gas is 100% methane.The low bleed emission factor is based on data from a different industry segment. The Subpart Wemission factor for continuous low-bleed pneumatic devices is from Table 5-15 from the APICompendium. The data used to develop this emission factor are included in Appendix B.5 of theAPI Compendium, and these data originate from the 1996 GRI/EPA Study. A review of thesedata shows: (1) the emission factor is based on a total of seven devices. Six of the devices arefrom a single Oil Battery measured for a 1992 Canadian Petroleum Association (CPA) study; and(2) the devices are from the production segment rather than natural gas transmission or storageoperations. The very limited data set, age ofthe data (20 years), and production segmentoperations suggest this emission factor may notrepresent emissions from low-bleed pneumaticdevices currently in use for natural gas transmission and storage operations.

# APPENDIX B

Summary of Issues from Internal Review Being Addressed by Proposed Amendments

Not all corrections and other amen dments correspond directly to questions that were raised by

reporters. The need for some corrections and ot her amendments were iden tified as a result of

internal EPA review. Below is a summary of the issues that have been raised from the EPA’s

review of Subpart W of Part 98.

Changes to 98.233

• Amend Equation W-7 by adding definition for index p.

• Clarify that 98.233 (f)(1)(i)(A ) is for pressure group and tubing diameter group

combinations.

• Amend the definition of parameter W in equation W-8 for consistency with data

reporting requirements.

• Clarify parameter SFR

p 

# under equation W-8 for consistenc y with referen ce to equation

W-33.

• Modify equation W-9 and associated parameters Z

p,q 

# , HR

p,q 

# , SFR

q 

# , and V

p 

# for

consistency.

• Amend the definition of parameter W in equation W-9 for consistency with data

reporting requirements.

• Clarify parameter SFR

p 

# under equation W-9 for consistenc y with referen ce to equation

W-33.

• Amend paragraph 98.233 (g) in troductory text and paragr aph (1) to specify that

measurements are used in Methodology 1 a nd calculations are used for Methodology 2.

• Amend Methodology 2 in paragraph 98.233 (g )(1)(ii) to change “measured” to

“calculated” well completions

• Clarify the definition for parameter FR

p 

# of Equation W-12 to not allow use of backflow

volume converted to flow rate.

• Amend paragraph 98.233(g)(3) by combining repetitive requiremen t from 98.233(g)(5).

Subsequently, 98.233(g)(5) was deleted.

• Clarify Equation W-13 by adding definition fo r the parameter “p” and clarifying that

emissions factor “EF WO 

# ” is the volume of na tural gas per workover.

• Clarify in 98.233(i) that the calculati ons are per “unique” physical volume.

• Modify Equation W-14A and associat ed parameter V for consistency.

• Clarify definition of N in equation W-14A.

• Modify equation W-14B and associated parameters V and P a,b,p 

# for consistency.

• Amend equation W-14B by adding definition fo r index p and clarify definition for N.

• Removal of paragraph 98.233 (i)(5).

• Clarify that the emission factor “EF i 

# ” in Equation W-15 is a p opulation emission factor.

• Clarify in paragraph 98.233 (k) that emissions must be monitored from a vent stack

connected to one or more transmission storage tank.

• Add a reference to (t), (u ), and (v) to convert emi ssions to metric tons CO 2 

# e in

98.233(k)(2).

71

# • Amend 98.233 (n)(9) by removing requirement to report CH 4 

# and N 2 

# O emissions from

flares monitored by CEMS.

• Clarified the parameter “T

s 

# ” in Equation W-31 to be the average estimated time.

• Modify 98.233 (u)(2)(vi) to allow LNG import f acilities to use a de fault composition of

95 percent methane and 1 percent carbon dioxide.

• Clarified the parameter “R j 

# ” and “Y j 

# ” in Equation W-39A.

Changes to 98.236

• Clarified that annual emissions must be reported by each GHG separately in the

introductory paragraphs in 98.236(a) and 98.236(c).

• Clarified that the amount of CO 2 

# recovered from the AGR unit and transferred outside

the facility must be reported under Subpart PP.

• Clarify that throughput for glycol dehydr ators is “annual aver age daily” in 98.236

(c)(4)(ii)(C) and (D).

• Addition of average flow rate of the meas ured liquids unloading event for Calculation

Methodology 1 reporting requirement fo r well venting for liquids unloading.

• Clarify that the average values of the inte rnal casing diameter, tubing diameter, and well

depth must be reported, for Calculation Me thodologies 2 and 3 for well venting for

liquids unloading.

• Modify 98.236 (c)(6)(i) to state that th e reporting requirements are for gas well

completions and workovers with hydraulic fracturing by sub-basin and well type

(horizontal or vertical) combination.

• Modify 98.236 (c)(9)(i) to state that reporting is required for each vent stack.

• Removal of data reporting require ment for using CEMS to report CH 4 

# and N 2 

# O from

flare stacks.

• Modify paragraph 98.236 (e) to change “aver age” to “best available estimate” for API

gravity, gas to oil ratio, and lo w pressure separator pressure.

Changes to 98.238

• Clarify definition for “Facility with resp ect to onshore petroleum and natural gas

production for purposes of reporting under this subpart and for the corresponding

Subpart A requirements.”

72