1

Summary of Public Comments and 

Responses for: 

2012 Technical Corrections, Clarifying and Other Amendments to 

the Greenhouse Gas Reporting Rule, and Confidentiality 

Determinations for Certain Data Elements of the Fluorinated Gas 

Source Category
2

August 2012

2012 Technical Corrections, Clarifying and Other Amendments to 

the Greenhouse Gas Reporting Rule, and Confidentiality 

Determinations for Certain Data Elements of the Fluorinated Gas 

Source Category:

Responses to Public Comments

U. S. Environmental Protection Agency

Office of Atmosphere Programs

Climate Change Division

Washington, D.C.
3

FOREWORD 

This document provides EPA’s responses to public comments on the Proposed 2012 

Technical Corrections, Clarifying, and Other Amendments to Greenhouse Gas Reporting Rule, and 

Proposed Confidentiality Determinations for Certain Data Elements of the Fluorinated Gas Source 

Category. The EPA published a Notice of Proposed Rulemaking in the Federal Register on May 

214, 2012 (77 FR 29935). The proposed amendments are designed to provide greater clarity for 

existing requirements, correct errors, and provide additional flexibility for facilities subject to 

reporting emissions from the following source categories: petroleum and natural gas systems (40 

CFR part 98, subpart W); electronics manufacturing (40 CFR part 98, subpart I); fluorinated gas 

production (40 CFR part 98, subpart L); and industrial waste landfills (40 CFR part 98, subpart 

TT). The notice also included amendments to Table A-7 of subpart A to include one additional 

subpart L data element used as an input to emission equation and confidentiality determinations 

for four new subpart L data elements added to the reporting requirements as part of this 

rulemaking. 

During the 30-day comment period for the proposed rule, the EPA received ten comment 

letters. This document provides the EPA’s responses to public comments regarding the proposed 

amendments. The verbatim text of each comment extracted from the original comment letters is 

included in this document, arranged by subpart then by subject. For each comment, the name and 

affiliation of the commenter, the document control number (DCN) assigned to the comment 

letter, and the number of each comment excerpt are provided. The EPA’s responses to 

comments are provided immediately following each comment excerpt. In some cases, the EPA 

provided responses to specific comments or groups of similar comments in the preamble to the 

final rule. Rather than repeating those responses in this document, the EPA has referenced the 

preamble to the final rule. Copies of all comment letters submitted are available at the EPA 

Docket Center Public Reading Room or electronically through http://www.regulations.gov by

searching Docket ID EPA-HQ-OAR-2011-0147. 

For additional information on EPA’s Greenhouse Gas Reporting Program and this and 

other amendments to the Greenhouse Gas Reporting Rule, please see 

http://www.epa.gov/climatechange/emissions/ghgrulemaking.html
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The primary contact regarding questions or comments on this document is: 

Carole Cook (202) 343-9263 

U.S. Environmental Protection Agency

Office of Atmospheric Programs 

Climate Change Division 

Mail Code 6207-J 

1200 Pennsylvania Avenue, NW 

Washington, D.C. 20460 

For technical information, contact the Greenhouse Gas Reporting Rule Hotline at: 

http://epa.gov/climatechange/emissions/ghgrule_contactus.htm
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TABLE OF CONTENTS

Section Page

I. Comments on the Proposed Amendments to Subpart A.............................................................................7

II. Comments on the Proposed Amendments to Subpart TT ..........................................................................7

III. Comments on the Proposed Amendments to Subpart W .....................................................................12

General Comments on the Subpart W Proposal..................................................................................................12

Comments on Equation W-6...............................................................................................................................13

Comments on the Proposed Amendments to Equation W-10A and W-10B.......................................................15

Comments on the Proposed Amendments to Equation W-12.............................................................................15

Comments on Equation W-14A..........................................................................................................................16

Comments on Amendments to the Compressor Provisions................................................................................17

Comments on the Proposed Amendments to Equation W-33.............................................................................23

Comments on the Proposed Amendments to Equation W-36.............................................................................23

Comments on Proposed Changes to the Subpart W Tables................................................................................24

Out of Scope Comments on Subpart W..............................................................................................................24

IV. Comments on the Proposed Amendments and Confidentiality Determinations for Subpart L........34

Comments on the Methods Used to Determine Global Warming Potentials for Fluorinated Greenhouse Gases 

Reported under Subpart L...................................................................................................................................34

Comments on the Proposal to Report Emissions at the Facility-Level for Year 2011 and 2012 ........................36
6

LIST OF COMMENTERS

DCN Commenter Name Commenter Affiliation

EPA-HQ-OAR-2011-0147-0043 Jeff Applekamp Gas Processors Association (GPA)

EPA-HQ-OAR-2011-0147-0044 Dana Schnobrich 3M Company

EPA-HQ-OAR-2011-0147-0045 Joel Hall Mexichem Fuor Inc.

EPA-HQ-OAR-2011-0147-0046 Andrew Shroads SC&A, Inc.

EPA-HQ-OAR-2011-0147-0047 Lisa Beal Interstate Natural Gas Association 

of America (INGAA)

EPA-HQ-OAR-2011-0147-0048 Pamela Lacey American Gas Association (AGA)

EPA-HQ-OAR-2011-0147-0049 Brendan Mascarenhas American Chemistry Council (ACC)

EPA-HQ-OAR-2011-0147-0050 Karin Ritter American Petroleum Institute (API)

EPA-HQ-OAR-2011-0147-0051 Robert Reich DuPont Company

EPA-HQ-OAR-2011-0147-0052 Jerry Call American Foundry Society (AFS)
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I. Comments on the Proposed Amendments to Subpart A

There were no comments on the proposed amendments to subpart A.

II. Comments on the Proposed Amendments to Subpart TT

Commenter Name: Robert Reich

Commenter Affiliation: DuPont Company

Document Control Number: EPA-HQ-OAR-2011-0147-0051

Comment Excerpt Number: 1

Comment: DuPont strongly supports the Agency’s proposal to amend the definition of the Subpart

TT source category by adding at §98.460(c)(2)(xiii) the exclusion of “[o]ther waste material that has 

a DOC value of 0.3 weight percent (on a wet basis) or less.” Such an exclusion will eliminate the 

burden on industry for reporting on landfilling of biologically inert solids that have a volatile solids 

concentration greater than 0.5 weight percent, which is the current exclusion criterion under 

(c)(2)(xii). Notably, biologically inert carbon materials (e.g., particulate carbon, coke, etc.) do not 

meet the volatile solids exclusion criterion, but will meet the proposed criterion. Excluding such 

solids from reporting requirements under the mandatory reporting rule reduces substantial burden on 

industry without having any impact on actual greenhouse gas emissions reporting.

Response: The EPA thanks the commenter for their input. The EPA has amended subpart TT as 

proposed in the May 21, 2012.

Commenter Name: Jerry Call

Commenter Affiliation: American Foundry Society

Document Control Number: EPA-HQ-OAR-2011-0147-0052

Comment Excerpt Number: 1

Comment: AFS supports the proposed direct DOC value exclusion for those facilities that only

receive inert waste. 

For those facilities that have chosen to determine a waste-specific degradable organic content 

(through the application of anaerobic biodegradation (AB) methods such as OECD 311, etc.), it 

is appropriate to allow those facilities that only receive wastes with a DOC less than or equal to 

0.3% (on a wet weight basis) to be exempt from reporting requirements under Subpart TT. AFS 

has a member that has performed the alternate test method referenced by EPA, and the anaerobic 

biodegradation test procedures provide a more accurate value for DOC and better approximate 

the emissions of GHG versus the total volatile solids (TVS) method which assumes that all of the 

carbon in the waste sample is available for GHG releases.

Response: The EPA thanks the commenter for their input. The EPA has amended subpart TT as 

proposed in the May 21, 2012.
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Commenter Name: Jerry Call

Commenter Affiliation: American Foundry Society

Document Control Number: EPA-HQ-OAR-2011-0147-0052

Comment Excerpt Number: 2

Comment: AFS requests clarification regarding the number of test results from the use of AB as 

required to determine whether or not a facility meets the definition of the source category under 

subpart TT.

Although AFS supports the application of AB testing of waste streams disposed in industrial 

landfills for the estimation of Greenhouse Gas (GHG) emissions, the Subpart TT rules should 

further clarify the number of test results required to reach a determination of whether the source 

category is applicable to the landfill GHG reporting. According to 40 CFR Part 

98.460(c)(2)(xiii), any industrial landfill that has only received industrial materials that have a 

DOC value of 0.3 weight percent (wet weight basis) or less using a 60-day AB test procedure 

identified in Part 98.464(b)(4)(i)(A) would not be considered to be within the Industrial Waste 

Landfill Subpart TT source category, and therefore, would not have an obligation to report the 

GHG emissions from that industrial landfill. Subpart TT does not, however, specify how many 

samples of industrial waste must be collected and analyzed using the AB methods specified in 

Part 98.464(b)(4)(i)(A), with the exception of the reference in Part 98.464(b)(4)(i)(B), which 

refers to the minimum of two waste stream samples as typically required to meet the precision 

requirement specified in Part 98.464(b)(4)(i)(E). One 60-day AB test is sufficient to determine 

whether the waste going into an industrial landfill qualifies as inert (and therefore the industrial 

landfill is not part of this source category) since this method is so costly (> 10 x TVS per 

sample), is very difficult and time consuming to perform, and is not broadly performed at 

environmental laboratories.

Response: The EPA thanks the commenter for their input. The EPA agrees that one 60-day

anaerobic biodegradation test is sufficient to determine if the waste stream is inert and therefore 

may be excluded from reporting under 98.460(c)(2)(xiii). A clarification to this effect has been 

added to 98.464(b). Please see Section II.B of the preamble.

Commenter Name: Jerry Call

Commenter Affiliation: American Foundry Society

Document Control Number: EPA-HQ-OAR-2011-0147-0052

Comment Excerpt Number: 3

Comment: Reporting requirements for industrial landfills that receive or have received a 

mix of inert solid waste and non-inert solid wastes: As stated in 40 CFR 98.460(c)(2)(xiii), 

industrial landfills that receive or have received only wastes with a DOC value less than 0.3 

percent by weight per the approved AB test procedures (Part 98. 464(b)(4)(i)(A)) or that are 

defined as inert (Part 98.460(c)(2)(i) through (xii)), are not included in the Subpart TT 

subcategory. Based on this reading, it appears that if a landfill has ever accepted any waste not 

meeting either of these two criteria, it would be included in the Subpart TT subcategory, and 

would be required to report GHG emissions. This issue was raised during the e-GRRT Webinar 

on Subparts TT and II conducted by EPA on June 4, 2012. A question was posed to EPA 
9

regarding whether the owner of a facility covered by Subpart TT must report GHG emissions 

from both the inert and non-inert waste streams. EPA officials indicated that GHG emission 

calculations must be performed for the total waste content in the landfill, both non-inert and 

inert.

Landfill owners should be able to report on only the non-inert portion of the waste streams. EPA 

should clarify that GHG emissions from those individual waste streams that meet the exemption 

listed in Part 98.460(c)(2), or otherwise determined through sample analysis to be inert, should 

not have to be reported. This will reduce the burden of record-keeping for the landfill activities 

reducing its operating cost, and has no environmental GHG impact.

Should EPA require reporting on inert in addition to the non-inert waste streams, several 

reporting issues arise. For example, what value of DOC is to be used to estimate the GHG 

emissions? Does the owner report GHG emissions of “0” for all inert wastes? Does the owner 

report GHG emissions for the inert waste streams using a DOC value of 0.3 percent? Does the 

owner report GHG emissions for the inert waste streams by computing a DOC value using 

Equation TT-8 and assuming a Volatile Solids concentration of 0.5 percent? Does the owner 

report GHG emissions for the inert waste streams using a measured DOC value from application 

of test methods specified in Part 98.464(b)(4)(i)(A)? Does the owner report GHG emissions for 

the inert waste streams by computing a DOC values using Equation TT-8 and inputting a 

measured value for Volatile Solids (which would be less the or equal to 0.5 percent)? If 

measured values for DOC and/or Volatile Solids are used for the inert waste streams, does the 

owner have to have tested four quarterly inert waste samples and computed an average result, or 

do the results from one round of sampling suffice? These issues have not been adequately 

addressed in the regulation. Having to report GHG emissions from waste streams that have been 

defined as inert for GHG emission purposes is counterintuitive and burdensome.

Response: With regard to the appropriate value to use for inert waste streams, the reporter may

use either the default value in Table TT-1, DOC=0 for inert wastes listed in §98.460(c)(2), or 

measurement data (measured DOCx from an anaerobic biodegradation test or a DOCx value 

imputed from measured volatile solids concentration). If the Table TT-1 default value for DOC 

is used, the GHG emissions from the inert waste will also be 0. The rule requires reporting of 

information about each waste stream regardless of whether it is inert. Reporting requirements 

include a description of the waste stream and the quantity of waste disposed of in the landfill for 

each waste stream, among other data elements. These are existing requirements that remain 

unchanged by this amendment.

Commenter Name: Jerry Call

Commenter Affiliation: American Foundry Society

Document Control Number: EPA-HQ-OAR-2011-0147-0052

Comment Excerpt Number: 4

Comment: The requirement that an industrial landfill is subject to the subpart TT simply

because all of the waste streams placed in the landfill are not defined as inert according to 

98.460(C)(2) places an unfair regulatory burden on these landfills.
10

. . . it appears EPA only exempts from this subcategory those industrial landfills that have 

received industrial waste streams that are defined as inert according to Part 

98.460(c)(2). It is entirely possible that an owner could have an industrial landfill where only one 

of perhaps five individual waste streams does not meet the inert designation per Part 

98.460(c)(2). That being the case, the landfill is included in this source category and the owner 

must compute GHG emissions from the industrial landfill. If the single non-inert waste stream 

has a fairly low DOC (as measured according to Part 98.464(b)(4)(i)(A)) and the inert waste 

streams also have fairly low DOC, it is entirely possible that the computed GHG emissions from 

this landfill could be less than those from another landfill where all of the waste streams are 

defined as inert per Part 98.460(c)(2). For example, assume that the landfill in question accepts 

the following waste streams with the following characteristics.

Waste Identification Tonnage (metric tons) DOC

A 20,000 0.005

B 20,000 0.003

C 20,000 0.001

D 20,000 0.002

E 20,000 0.002

By applying Equation TT-5, one computes a bulk DOC value of 0.26 percent (or 0.0026). As 

stated in Part 98.460(c)(2)(xiii), if this landfill had only accepted waste streams that had DOC 

values of equal to or less than 0.3 percent, they would not be subject to this subcategory. By

accepting a single waste stream that exceeds the inert designation in Part 98.460(c)(2)(xiii), this 

landfill owner would have the regulatory burden associated with Subpart TT, while another 

landfill owner that only accepted one waste stream with a measured value for DOC of 0.3 

percent, would be exempt from this burden, even though its GHG emissions would be the greater 

of the two. This issue becomes even more significant when you compare the GHG emissions 

from a landfill that accepted only Construction and Demolition (C & D) Waste, which would 

have a DOC = 0.08 versus the bulk DOC value (0.0026) for the example landfill cited in this 

comment.

EPA has defined the C&D landfill as exempt from this subcategory while the example landfill is 

included in the subcategory. Clearly, the C & D landfill would generate significantly higher (by a 

factor of more than 30) GHG emissions than the example landfill; however the C & D landfill 

emissions would not have to be reported. While we agree with EPA’s exemption of C & D 

landfills from this subcategory, landfills that can be shown to emit an equivalent or lower level 

of GHG emissions should also be exempted from reporting.

Response: The EPA thanks the commenter for their input. The amendment to subpart TT 

provides an additional opportunity for exemption from the subpart TT requirements based on a 

DOC value measured using a 60-day anaerobic biodegradation test. This DOC value is 

consistent with the volatile solids concentration exemption provided in the rule and per 

§98.460(c)(2) is applicable to those industrial waste landfills that only receive one or more of the 

inert waste materials listed. In contrast, the comment is describing a scenario in which the 

landfill receives several inert waste streams on the list but also receives one waste stream that is 
11

not on this list because its DOC value is higher than the newly exempted level. The comment 

does not request that the exempted DOE value be adjusted higher. We have considered this 

comment, and concluded it is out of scope with the technical corrections, clarifying, and other 

amendments to certain provisions of the GHG Reporting Rule because it does not pertain to the 

proposed or final DOC value exemption. Rather the comment raises issue with the exemptions 

applying to only those landfills that only receive one or more of the inert wastes listed in 

§98.460(c)(2) and requests another exemption for landfills that also receive non-inert waste. 

This portion of the exemption language was not proposed for change in the proposed technical 

corrections, clarifying, and other amendments to certain provisions of the GHG Reporting Rule

Commenter Name: Jerry Call

Commenter Affiliation: American Foundry Society

Document Control Number: EPA-HQ-OAR-2011-0147-0052

Comment Excerpt Number: 5

Comment: The number of sampling events required to determine DOC using the methods 

specified in 98.464(B)(4)(I)(A) is unrealistic. In the November 29, 2011 Federal Register EPA 

published a final rule amending specific provisions of the Mandatory Reporting of Greenhouse 

Gases Rule (40 CFR Part 98) to correct certain technical and editorial errors. As part of that final 

rule, EPA amended Subpart TT to allow the use of 60-day AB procedures to determine DOC. 

However, according to Part 98.463(a)(3)(i), for the first year in which a facility determines GHG 

emissions, one has to determine the DOC value of a waste stream once per quarter using the 

methods specified in Part 98.464(b). AFS members have experience that the AB test methods 

typically require 90 days or more from the time that a sample is collected until final results are 

provided by the laboratory. Also, these procedures typically require analysis of two or more 

waste samples in order to assess the precision of the results. The procedure is also significantly 

more expensive then Method 2540G.

Given the longer duration of this test procedure, the number of samples actually tested as part of 

sample analysis (minimum of two and sometimes as many as four), the added expense, and the 

fact that the procedure provides more direct measurements of DOC, AFS requests that EPA 

allow the use of a single set of annual sampling using the 60-day anaerobic biodegradation 

method. This is consistent with the amount of sampling required to exempt a landfill from being 

included in this subcategory.

Response: The EPA thanks the commenter for their input. The amendment to subpart TT 

provides an additional opportunity for exemption from the subpart TT requirements based on a 

DOC value measured using a 60-day anaerobic biodegradation test. This DOC value is 

consistent with the volatile solids concentration exemption provided in the rule. In contrast, the

comment is about the testing requirements if a landfill is required to report, i.e. is not exempt, 

and wants to determine its own measured DOC value rather than using the default values 

provided in the rule. We have considered this comment and concluded that it is out of scope in 

relation to the proposed and final technical corrections, clarifying, and other amendments to 

certain provisions of the GHG Reporting Rule because it does not pertain to the opportunity for 

exemption or the testing required to determine whether an exemption is allowed. The testing 

required for determining exemption to the rule is separate from the requirements for determining 
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a waste stream-specific DOC value that is subsequently used to calculate methane generation and 

emissions for purposes of accurate reporting of GHG emissions from the facility.

III. Comments on the Proposed Amendments to Subpart W

General Comments on the Subpart W Proposal

Commenter Name: Jeff Applekamp

Commenter Affiliation: Gas Processors Association

Document Control Number: EPA-HQ-OAR-2011-0147-0043

Comment Excerpt Number: 2

Comment: The description of the change to table W-1A has a typo:

“Table A-1A W-1A to Subpart W of part 98 is revised to read as follows:”

Response: Due to a typographical error made at the time of the December 23, 2011 (see 77 FR 

80554) amendments, the first table listed in subpart W was incorrectly identified as “Table A1A” instead of “Table W-1A.” In the May 21, 2012 notice, we proposed corrections to subpart 

W that included the correction to the title for this table. Following Federal Register convention, 

the May 21, 2012 amendatory language correctly cited “Table A-1A” using the title of the table 

as it appeared in the Federal Register and Code of Federal Regulations. Therefore, no changes 

are necessary as a result of this comment. In this action, EPA has finalized a correction to the 

table name such that the table is correctly titled as “Table W-1A.”

Commenter Name: Lisa Beal

Commenter Affiliation: Interstate Natural Gas Association of America (INGAA).

Document Control Number: EPA-HQ-OAR-2011-0147-0047

Comment Excerpt Number: 11

Comment: Implementing these proposed amendments and incorporating them into the 

requirements for the data that must be reported to EPA by September 2012 is inappropriate and 

could cause significant problems, especially since the effective date of final rules is unknown 

and reporting is due in approximately three months. 

INGAA cannot support a rulemaking process that issues final rules that require response times in 

weeks or less. For Subpart W reporting of 2011 emissions, operators have been developing 

systems, compiling data, and completing calculations for reportable data elements for more than 

18 months. In addition, operators have submitted requests to use Best Available Monitoring 

Methods (BAMM), often due to the ongoing evolution and uncertainty with Subpart W 

requirements. The pending BAMM requests were filed in the context of the current rule (that is, 

without the Proposed Rule’s technical corrections). Conflicts could result if Subpart W changes. 

The burden of requiring operators to assess and incorporate summertime revisions to Subpart W 

is not trivial, and mandating that reports filed in September reflect content rules unknown until 

July or August is not reasonable. 
13

For example, while INGAA can note inconsistencies within the Proposed Rule’s compressor 

equations and areas within those equations where clarity remains lacking — as INGAA has done 

in these comments — operators cannot presume how these issues will be reconciled. Meanwhile, 

reports are being prepared based on the current interpretation and as reflected in BAMM 

requests. Thus, while INGAA recommends that EPA complete this technical correction 

rulemaking expeditiously, it should not mandate conformance for September 2012 reporting. 

Response: In response to the commenters first point about significant problems arising due to 

implementing and incorporating the proposed amendments in time for the September 28, 2012 

reporting deadline, EPA has noted in the preamble to the 2012 Technical Corrections proposal, 

(77 FR 29935, hereinafter referred to “2012 Technical Corrections proposal”) and section I.D. of 

the final rule, that these amendments include technical corrections that include typographical 

errors, errors in citations, minor clarifications in rule text, and changes to data reporting 

requirements aimed at streamlining the data reporting process for reporters. For example, in the 

2012 Technical Corrections proposal, EPA proposed a change to the emission factors in Table 

W-1A to account for an error in conversion of those emission factors to account for a change in 

standard temperature and pressure. In this action, EPA is finalizing amendments to this emission 

factors, and while reporters will need to use the updated emission factors when calculating their 

GHG emissions, EPA does note that this type of change is not expected to result in a large 

burden on the reporters. 

Regarding the commenters point about operators who submitted Best Available 

Monitoring Method (BAMM) requests that are pending final determination, EPA will consider, 

as stated in the subpart W final rule, BAMM requests that meet the criteria outlined in the 

provisions of 40 CFR 98.234(f). EPA does believe that reporters would have sufficient time to 

implement the amendments finalized in this rulemaking.

In response to the commenter’s not about inconsistency between the 2012 Technical 

Corrections Proposal regarding compressor provisions, EPA has addressed comments that were 

submitted on the proposal for both the centrifugal and reciprocating compressor emissions 

sources as appropriate and in this action, specific amendments have ben finalized that are within 

the scope of this rulemaking. 

Lastly, because this is the first year of submission of subpart W reports to EPA, a 

significant amount of outreach has been done information reporters and the regulated community 

of these proposed changes along with demonstrations of how the reporting forms would be 

affected as a result of finalizing the amendments in the 2012 Technical Corrections proposal. 

EPA believes that the amendments finalized in this action can be implemented for the September 

28, 2012 data reporting deadline. Please see the section “How will these amendments apply to 

2012 reports? in the preamble to the final rule for additional background information in response 

to this comment. 

Comments on Equation W-6

Commenter Name: Jeff Applekamp

Commenter Affiliation: Gas Processors Association

Document Control Number: EPA-HQ-OAR-2011-0147-0043

Comment Excerpt Number: 1
14

Comment: Equation W-6 does not work for the natural gas processing industry, where desiccant 

dehydrator mol sieve is commonly used. This type of desiccant is regenerated without opening 

the vessel to atmosphere. The vessel is only opened to atmosphere once every 3 or 4 years when 

the mol sieve needs to be replaced.

Equation W-6 is set up for dehydrator change-outs that occur at least once a year, due to the 365 

day factor in the numerator and the variable “T” in the denominator. Equation W-6 results in 

calculated emissions that are too low if the time between refilling is greater than 365 days.

Thus, Equation W-6 should be changed to correctly calculate emissions from desiccant dehys

[sic] that are changed out less than one time per year. This equation should be:

Es,n = (H*D2*P*P2*%G*N) / (4*P1*100)

Where:

Es,n = Annual natural gas emissions at standard conditions in cubic feet.

H = Height of the dehydrator vessel (ft).

D = Inside diameter of the vessel (ft).

P1 = Atmospheric pressure (psia).

P2 = Pressure of the gas (psia).

P = pi (3.14).

%G = Percent of packed vessel volume that is gas.

N = Number of dehydrator change-outs per year.

100 = Conversion of %G to fraction.

For example, assume that the desiccant is changed out about once every three years. We’ll

use 900 days for T. 

Assume:

H=20 feet

D=7 feet

P1 = 14 psia

P2 = 500 psia

%G = 20%

T = 900 days

Using the Equation W-6 that is currently in the proposed rule, we get:

Es,n = (H * D2 * P * P2 * %G * 365) / (4 * P1 * T * 100)

= (20 * (7 * 7) * 3.14 * 500 *20 * 365) / (4 * 14 * 900 * 100)

= 11,231,780,000 / 5,040,000

= 2,229 SCF/YR

Using the version we are proposing in this comment, we get:

Es,n = (H*D2*P*P2*%G*N) / (4*P1*100)

= (20 * (7 * 7) * 3.14 * 500 * 20 * 1) / (4 * 14 * 100)

= 5,495 SCF/YR
15

Response: EPA has reviewed the comment submitted by the commenter and in this action is 

finalizing the amendment suggested by the commenters. For the response to this comment, 

please see Section II.C.2 of the preamble to the final rule.

Comments on the Proposed Amendments to Equation W-10A and W-10B

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 3

Comment: EPA has proposed to change the subscripts for the term PRp to PRs,p for Equation W10A. API suggests also modifying the definition of this term as follows: 

First 30-day average production flow rate in standard cubic feet per hour of each well p, under 

actual conditions, converted to standard conditions, as required in paragraph (g)(1) of this 

section.

Response: The EPA agrees with the commenter’s recommended revisions to the definition of 

the term “PRs,p” and has amended Equations W-10A of subpart W as recommended by the 

commenter. 

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 4

Comment: EPA has proposed to change the subscripts for the term SGp to SGs,p for Equation 

W-10A and EnFp to EnFs,p for Equations W-10A and W-10B. API notes the following 

inconsistencies in the use of these terms and indicates the corrections . . . below:

EnFs,p = Volume of CO2 or N2 injected gas in cubic feet at standard conditions that was 

injected into the reservoir during an energized fracture job for each well p. If the fracture 

process did not inject gas into the reservoir, then EnFp EnFs,p is 0. If injected gas is 

CO2 then EnFp EnFs,p is 0. 

SGs,p = Volume of natural gas in cubic feet at standard conditions that was recovered 

into a flow-line for well p as per paragraph (g)(3) of this section. This parameter 

includes any natural gas that is injected into the well for clean-up. If no gas was 

recovered, SGp SGs,p is 0.

Response: The EPA agrees with the commenter’s recommended revisions to the definitions of 

the terms “EnFs,p” and “SGs,p” and has amended Equations W-10A and W-10B of subpart W as 

recommended by the commenter. 

Comments on the Proposed Amendments to Equation W-12
16

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 5

Comment: EPA has made corrections to the terms defined for Equation W-12, which is part of 

the emission estimation methods for gas well completions and workovers with hydraulic 

fracturing. These revisions include replacing the term “backflow” with “flowback”. API 

requests that the term “backflow” be replaced with “flowback” throughout Subpart W. API also 

notes that the word “formation” should be changed to “combination” in the revised definition of 

the term “N”, as well as for the term “W”, as shown below. 

N = Number of measured or calculated well completions or workovers using hydraulic 

fracturing in a sub-basin and well type formation combination. 

W = Number of wells completed or worked over using hydraulic fracturing in a subbasin and well type formation combination.

Response: In response to the commenters first point about making a global change throughout 

subpart W to replace the term “backflow” to “flowback”, EPA has considered this comment, and 

concludes it is out of scope with the technical corrections, clarifying, and other amendments to 

certain provisions of the GHG Reporting Rule. While EPA’s original intent was that both terms 

had the same meaning in the context of subpart W, EPA is considering EPA is considering 

replacing the term “backflow” which is used extensively in the subpart W rule text with the term 

“flowback” by way of an amendment to subpart W in the near future. EPA is also considering 

inclusion of a definition of the term in subpart W to further clarify EPA’s intent. 

In response to the commenters’ second comment about replacing the term “formation” with 

“combination” in the definition of parameter “N” and “W” in Equation W-12, EPA agrees with 

the commenter and has finalized that correction in this final rule. 

Comments on Equation W-14A 

Commenter Name: Andrew Shroads

Commenter Affiliation: SC & A, Inc.

Document Control Number: EPA-HQ-OAR-2011-0147-0046

Comment Excerpt Number: 1

Comment: §98.233(i)(3) contains two equations. Equation W-14A has an error with the purge 

factor that causes the equation to yield erroneous results. The equation subtracts a "purge factor" 

from the volume of the item being evacuated of natural gas (i.e., blowdown), converted to 

standard cubic feet. The "purge factor" is either 0, if a non-GHG gas is used to purge the item, or 

1 if the item is not purged. Since the volume being purged is converted from actual cubic feet to 

standard cubic feet, inconsistent units are being subtracted, (i.e. standard cubic feet purged and 

actual cubic feet "purge factor"). This also results in a negative number if the volume of the 

purged item in standard cubic feet is less than in actual cubic feet, (i.e. actual conditions are 

hotter or a lower pressure than standard conditions). Additionally, the "purge factor" does not 

make sense in the way it is described. If the item is not being purged, then the calculation should 
17

not be used, as there would be no GHG emissions from the blowdown stack, rather than 

including it in the calculation.

Response: EPA has reviewed this comment and disagrees with the commenter. For a response 

to this comment, please see section II.C.2 of the preamble to the final rule. 

Comments on Amendments to the Compressor Provisions

Commenter Name: Lisa Beal

Commenter Affiliation: Interstate Natural Gas Association of America (INGAA).

Document Control Number: EPA-HQ-OAR-2011-0147-0047

Comment Excerpt Number: 1

Comment: Equation W-23 

In § 98.233(o)(5), EPA proposes to revise Equation W-23 by removing the summation. This 

change is not adequate to correct Equation W-23, and additional revisions are warranted. 

INGAA recommends clarifications that are consistent with EPA’s stated intent that compressor 

emissions be reported based on measurements when measured data is available for the site that 

year, and that emission factors be developed for reporting compressor emissions for modes not 

measured. EPA’s intent has been expressed in meetings, and is also reflected in the data elements 

reported in § 98.236(c) and the data fields in the Subpart W e-GGRT template. 

It appears that § 98.233(o)(5) is intended to calculate annual emissions based on reporter-defined 

emission factors for modes not measured in a particular year, and EPA desires reporting that 

considers not only the mode but also the emission source. For example, for centrifugal 

compressors with wet seals in the operating mode, an emission factor would be developed and 

emissions calculated for the two sources: blowdown valve leakage for wet and dry seal 

compressors per § 98.233(o)(1)(i) and wet seal oil degassing vent emissions per § 

98.233(o)(1)(ii). 

In the current rule with the summation, the implication is that a single mode-based estimate 

would be completed that adds the emissions from the two sources. By removing the summation 

in Equation W-23 in the Proposed Rule, that is no longer the case. However, the equation needs 

to capture not only emissions from the mode (i.e., subscript “m” in the equation), but also from 

the unique mode-source combination (e.g., operating mode-wet seal degassing and operating 

mode-blowdown valve leakage). This could be achieved by adding another subscript to the 

parameters in Equation W-23 or re-defining subscript “m” to apply to the relevant combination 

of operating mode and emission source. In the latter case, the mode-source combinations should 

be listed after the equation to add clarity. 

There are three unique mode-emission source combinations for centrifugal compressors: 

• Operating mode-blowdown valve leakage [see § 98.233(o)(1)(i)]; 

• Operating mode-wet seal oil degassing vent [see § 98.233(o)(1)(ii)]; and 

• Not operating, depressurized mode-unit isolation valve leakage [see § 98.233(o)(1)(iii)]. 
18

To summarize, the current rule needs to be corrected because the summation term is not properly 

annotated and the summation would not provide an emission estimate specific to the unique 

combination of emission source and operating mode, as intended by EPA. The Proposed Rule 

removes the summation term, but results in an equation that is incomplete because it addresses 

the mode but does not address the associated unique emission source. If there is only one 

relevant source for the mode, then this is not an issue. For modes with more than one source (i.e., 

operating mode for both centrifugal and reciprocating compressors), the revised equation and 

parameter definitions are incomplete. If Equation W-23’s parameters are not revised to capture 

each distinct combination of operating mode and emission source, the Proposed Rule’s technical 

corrections will simply replace one unclear equation with another. 

Response: EPA has reviewed the comment submitted by the commenter and in this action is 

finalizing a revision to the definition of parameter “E,s,i” to “E,s,i,m”, in Equation W-23 in 

response to this comment. For more on EPA’s response to this comment, please see Section 

II.C.2 of the preamble to the final rule. 

Commenter Name: Lisa Beal

Commenter Affiliation: Interstate Natural Gas Association of America (INGAA).

Document Control Number: EPA-HQ-OAR-2011-0147-0047

Comment Excerpt Number: 2

Comment: Equation W-24 for centrifugal compressors suffers from the same problem. The 

Proposed Rule appropriately corrects the summation term by placing it in the numerator of the 

equation. However, the summation is mode-specific, so Equation W-24 would provide two 

emission factors – one for operating mode and one for not operating, depressurized mode. That is 

not consistent with reporting requirements and proposed e-GGRT data fields for unique modesource combinations. To correct this problem, EPA should clarify Equation W-24 by revising the 

definition of parameter “m” to, “Unique compressor mode and emissions source combinations 

as listed in paragraph (o)(1)(i) through (o)(1)(iii).” For clarity, the three unique combinations 

should be listed along with the definition of “m”.

Response: EPA has reviewed the comment submitted and in this action is finalizing a revision 

to the definition of the parameters “MTm,p” and “m” in Equation W-24 and W-28. For our 

response to this comment, please see Section II.C.2 of the preamble to the final rule.

Commenter Name: Lisa Beal

Commenter Affiliation: Interstate Natural Gas Association of America (INGAA).

Document Control Number: EPA-HQ-OAR-2011-0147-0047

Comment Excerpt Number: 3

Comment: Equations W-27 and W-28 

The same issue applies for reciprocating compressors in proposed revisions to Equations W-27 

and W-28 in § 98.233(p)(7). For reciprocating compressors, there are four unique mode-source 

combinations, as identified in § 98.233(p)(1) through (p)(3). Without repeating the details, 

similar revisions to those discussed above for centrifugal units are needed for § 98.233(p). 
19

Response: EPA has reviewed the comment submitted and in this action is finalizing a revision 

to the definition of parameter “Es,i,m” in Equations W-23 and W-27, and a revision to the 

definitions of parameters “MTm,p” and “m” in Equations W-24 and W-28. EPA is considering 

the additional changes requested by the commenter in a future rulemaking. For more on EPA’s 

response to this comment, please see EPA-HQ-OAR-2011-0147-1 and EPA-HQ-OAR-2011-

0147-2, and Section II.C.2 of the preamble to the final rule. 

Commenter Name: Lisa Beal

Commenter Affiliation: Interstate Natural Gas Association of America (INGAA).

Document Control Number: EPA-HQ-OAR-2011-0147-0047

Comment Excerpt Number: 5

Comment: Content of methane and CO2 in natural gas: default value 

In late 2011 EPA introduced changes that reference § 98.233(u) and allow T&S sources to use 

default values for methane and CO2 content in natural gas. However, following Equation W-23 

for centrifugal units and Equation W-27 for reciprocating units, the parameter “GHGi” is defined 

as “1” (i.e., assume 100% CO2 and 100% methane in the gas). This conflicts with other Subpart 

W requirements and should be corrected. References to GHGi should consistently refer to the 

default values and/or section § 98.233(u). 

Response: For a response to this comment please see EPA response to comment excerpt EPAHQ-OAR-2011-0147-0047-7 7. 

Commenter Name: Lisa Beal

Commenter Affiliation: Interstate Natural Gas Association of America (INGAA).

Document Control Number: EPA-HQ-OAR-2011-0147-0047

Comment Excerpt Number: 7

Comment: Parameter EFm. 

For parameter EFm in Equation W-24, the reference to “three modes” should be revised. This 

relates to the discussion above [see comment EPA-HQ-OAR-2011-0147-0047, 

excerpt 3] regarding modes versus unique mode-emission source combinations. Based on 

revisions discussed above, the EFm definition should refer to three “unique mode-emission 

source combinations” for centrifugal units. Similarly, following Equation W-28 for reciprocating 

compressors, EFm refers to three modes. In this case, it should refer to “four unique modeemission source combinations.”

Response: The EPA thanks the commenter for their input. In the preamble to the 2012 

Technical Corrections proposal, (77 FR 29941), EPA stated that the amendments proposed in 

that action for both centrifugal and reciprocating compressors emission sources were limited to 

minor corrections to certain equations, where the amendments proposed for these equations were 

such that owners and operators would, if finalized, correctly calculate GHG emissions from these 

emission sources. In response to the commenters’ suggestion for further revisions to provisions 

in both the centrifugal and reciprocating compressor emission sources, although EPA is 

considering inclusion of the amendment(s) suggested by the commenter in a future rulemaking . 
20

EPA is maintaining the same intent to keep the amendments to the calculation methodologies for 

these emissions sources limited for the same reasons as stated in the preamble to the 2012 

Technical Corrections proposed rule, and has thus concluded that this comment is out of the 

scope of the 2012 Technical Corrections final rule. 

Commenter Name: Lisa Beal

Commenter Affiliation: Interstate Natural Gas Association of America (INGAA).

Document Control Number: EPA-HQ-OAR-2011-0147-0047

Comment Excerpt Number: 9

Comment: For the equations in the compressor sections, introductory text should be added to 

clarify the intent of the equations and how reporting entities are to use them. 

As Subpart W has undergone revisions and additional material is released by EPA, the intended 

approach for compressor emissions —measurement, calculations, and data roll-up — is 

becoming clear. For example, it appears that measured data are to be used for estimates when 

annual measurements are completed in that mode. For modes not measured, operator emission 

factors are used. To express this intent clearly, EPA should adopt introductory text, as 

summarized in section E below, to accompany the equations in §§ 98.233(o) and (p). 

E. Summary of technical corrections and clarifications for compressor equations. 

• Equations W-22 and W-26 should include an introductory phrase to clarify that these equations 

are for estimating emissions based on the annual site measurement: - Revise § 98.233(o)(4):

“For modes measured in the reporting year, estimate annual emissions using the flow 

measurement ...” 

- Revise § 98.233(p)(6): “ For the modes measured in the reporting year, estimate annual 

emissions using the flow measurement...” 

• Similarly, Equations W-23 and W-27 should include an introductory phrase to clarify that these 

equations are for estimating emissions based on operator emission factors for modes not 

measured that year: : - Revise § 98.233(o)(5): “For the mode not measured in the reporting 

year, calculate annual emissions from each centrifugal compressor...” 

- Revise § 98.233(p)(7): “For modes not measured in the reporting year, calculate annual 

emissions from each reciprocating compressor ...” 

• Parameter “m” should be re-defined in both § 98.233(o) and § 98.233(p) to address not just the 

mode, but the unique mode-emission source combination. When “m” is defined, the three unique 

combinations for centrifugal units and four unique combinations for reciprocating units should 

be re-iterated to provide clarity. 

• The erroneous reference to “GHGi = 1” following Equations W-23 and W-27 should be deleted 

and § 98.233(u) should be consistently referenced for gas quality. 
21

• The term “GHGi” should be used consistently in all equations rather than adding the mole 

fraction term in Equations W-22 and W-26. 

• For the term “EFm” in Equations W-24 and W-28, reference to the number of modes should be 

revised to reflect the number of unique mode-emission source combinations.

• For Equation W-22, the term “1–Bm” should be deleted because it is not consistent with the § 

98.233 format for addressing vapor recovery (or flaring, etc.). Instead, a section analogous to § 

98.233(p)(8) should be added to § 98.233(o). 

Response: For a response to this comment please see EPA response to comment excerpt EPAHQ-OAR-2011-0147-0047 Comment Excerpt Number 7.

Commenter Name: Lisa Beal

Commenter Affiliation: Interstate Natural Gas Association of America (INGAA).

Document Control Number: EPA-HQ-OAR-2011-0147-0047

Comment Excerpt Number: 10

Comment: Consistent Reporting In Mass-Based Units 

In the Subpart W reporting section, annual emissions should be reported as metric tons of CO2e, 

and equations should not be cited in § 98.236(c)(13) and § 98.236(c)(14) that provide results 

with different engineering units. 

Reporting by emission source type is defined in § 98.236(c). For centrifugal compressors, the 

Proposed Rule revises § 98.236(c)(13)(iii)(C) because it references engineering units of cubic 

feet per hour. For reporting, the desired engineering unit is metric tons. INGAA agrees, and 

recommends that data elements that report annual emissions in §§ 98.236(c)(13) and (14) 

consistently report on a mass basis. 

However, throughout § 98.236(c)(13) for centrifugal compressors and § 98.236(c)(14) for 

reciprocating compressors, annual emissions data elements are identified where reporting in 

metric tons is desired, but the sections reference equations in § 98.233(o) and § 98.233(p) that 

calculate emissions with results in volume (scf) engineering units. This direct reference of 

engineering units from the equations conflicts with the mass-based units desired. The reference 

to § 98.233 equations should be deleted from the data elements in §§ 98.236(c)(13) and (14) that 

report annual emissions. 

Response: EPA agrees with the commenter and in this action has finalized amendments to the 

units for the reciprocating and centrifugal compressor data elements in 40 CFR 98.236. Please 

see Section II.C of the preamble to the final rule for more on EPA’s response to this comment. 

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 6
22

Comment: EPA has removed the summation for Equation W-23. With this revision, Equation 

W-23 now reflects the emissions for the mode, not the entire compressor. Either the term Es,i

needs to be revised to Es,i,m to reflect emissions for a particular mode, as represented by the 

equation (in which case the definition for Es,i,m should be “Annual total volumetric GHG 

emissions at standard conditions from each centrifugal compressor mode in cubic feet”), or the 

summation should be added back in with an upper limit of 3, consistent with the three possible 

operating modes (no change would be required for Es,i).

Response: The EPA agrees with the commenter’s recommended clarifications and has amended 

Equation W-23 of subpart W such that the term “Es,i” is revised to “Es,i,m” and is defined as 

follows “Annual total volumetric GHG emissions at standard conditions from each centrifugal 

compressor for mode-source combination m in cubic feet.” Please see section II.C.2. of the 

preamble to the final rule for EPA’s response to this comment. 

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 7

Comment: EPA has changed the subscript for the term MTm to MTm,p in Equation W-24 and W28. EPA did not modify the subscript for the definition of the term MTm following these two 

equations. EPA also did not define the subscript “p” for either of these equations.

Response: For a response to this comment, please see EPA-HQ-OAR-2011-0147-0047 – 2 and 

For a response to this comment, please see EPA-HQ-OAR-2011-0147-0047 - 3. 

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 8

Comment: EPA has removed the summation for Equation W-27. With this revision, Equation 

W-27 now reflects the emissions for the mode, not the entire compressor. Either the term Es,i 

needs to be revised to Es,i,m to reflect emissions for a particular mode, as represented by the 

equation (in which case the definition for Es,i,m should be “Annual total volumetric GHG 

emissions at standard conditions from each reciprocating compressor mode in cubic feet”), or 

the summation should be added back in with an upper limit of 3, consistent with the three 

possible operating modes (no change would be required for Es,i).

Response: The EPA agrees with the commenter’s recommended clarifications and has amended 

Equation W-27 of subpart W such that the term “Es,i” is revised to read “Es,i,m.” We have also 

revised the definition of “Es,i,m to read “Annual total volumetric GHG emissions at standard 

conditions from each reciprocating compressor for mode-source combination m, in cubic feet.”

For more on EPA’s response to this comment, please see For a response to this comment, please 

see EPA-HQ-OAR-2011-0147-0047 – 2, and Section II.C of the preamble to the final rule. 
23

Comments on the Proposed Amendments to Equation W-33

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 9

Comment: EPA has modified the definition of terms Es,n and Ea,n for Equation W-33 to address 

the substitution of FRs,p for Es,n and FRa,p for Ea,n when converting volumetric flowrates from 

98.233(g). API does not take issue with the revisions proposed to paragraph “t”, as it is 

consistent with how API members interpreted the requirements. However, API suggests 

modifications to the proposed revisions for the terms Es,n and Ea,n as indicted below. Removing 

the parentheses around the FRs,p and FRa,p terms clarifies the revisions. 

Es,n = Natural gas volumetric emissions at standard temperature and pressure (STP) 

conditions in cubic feet, except Es,n equals (FRs,p) for each well p when calculating 

either subsonic or sonic flowrates under 98.233(g). 

Ea,n = Natural gas volumetric emissions at actual conditions in cubic feet, except Ea,n 

equals (FRa,p) for each well p when calculating either subsonic or sonic flowrates under 

98.233(g)

Response: The EPA agrees with the commenter’s recommended clarifications and has amended 

Equation W-33 of subpart W as suggested by the commenter. 

Comments on the Proposed Amendments to Equation W-36

Commenter Name: Pamela Lacey

Commenter Affiliation: American Gas Association

Document Control Number: EPA-HQ-OAR-2011-0147-0048

Comment Excerpt Number: 1

Comment: AGA appreciates EPA’s proposal in the 2012 Proposed Technical Corrections to 

correct the density factor for methane in 98.233(v). See 77 Fed. Reg. at 29951. 

Equation W-36 in the current version of 98.233(v) uses engineering units of kilograms per SCF, 

but in 2011 rule revisions, EPA changed the value that one is required to use for methane density 

and failed to use the appropriate value as measured in kilograms per standard cubic foot. Instead, 

EPA’s Technical Corrections final rule changed the value to “0.0422” -- which is the methane 

density value stated in pounds per SCF. If one divides the required value of AGA 0.0422 (the 

density of methane in lbs / SCF) by 2.2 lbs per kg , this results in a density of 0.0192 kg / SCF, 

which is the appropriate value in units of kg / SCF). 

In the 2012 Proposed Technical Corrections EPA is now proposing to replace 0.0422 with 

0.0192 in Equation W-36. This proposed revision will fix the error and eliminate the confusion 

between pounds and kilograms that otherwise would have over-estimated emissions by a factor 

of more than two (i.e. 2.2). AGA supports this proposed correction. 
24

Response: The EPA thanks the commenter for their input. The EPA has finalized the 

amendment to Equation W-36 of subpart W as proposed in the 2012 Technical Corrections 

proposal (77 FR 29935).

Comments on Proposed Changes to the Subpart W Tables

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 2

Comment: EPA has indicated that the May 21, 2012 proposed technical amendments correct 

errors associated with several emission factors, but otherwise did not update or revise the 

emission factors. While API appreciates that EPA has corrected errors with some of the emission 

factors, it is not clear why EPA increased the emission factors for valves, flanges, connectors, 

open-ended lines, and “other” components shown in the following table.

December 2011 

Amendment 

Emission Factor 

EPA Proposed 

Revised Emission 

Factors (May 2012) 

Table W-1A. Onshore Petroleum and Natural Gas Production – Eastern 

and Western U.S. 

Population Emission Factors – All Components Light Crude Service 

Component Scf/hour/component Scf/hour/component 

Valve 0.04 0.05 

Flange 0.002 0.003 

Connector 0.005 0.007 

Open-ended Line 0.04 0.05 

Other 0.23 0.30 

API had not previously commented on the light crude emission factors shown above, because the 

values published by EPA were close to API’s estimates when rounded up. It is not clear what 

prompted EPA to suggest the highlighted revisions. API requests that EPA not revise these 

emission factors and maintain the current values.

Response: EPA disagrees with the commenter’s suggestion to revise the population emission 

factors for Light Crude Service for the Onshore Petroleum and Natural Gas Production industry

segment. For the response to this comment, please see Section II.C.2 of the preamble to the final 

rule. 

Out of Scope Comments on Subpart W

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 1
25

Comment: API notes that EPA has proposed to modify 98.233(t), such that if an equation from 

98.233 results in a gas volume at standard conditions then paragraph “t” does not apply. API 

supports this revision. However, it does not appear to address API’s issues with individual 

equations that result in gas volumes at actual conditions, when industry practice is to track gas 

flow rates at standard conditions.

API continues to insist that EPA allow the use of industry standard conditions of 60°F and 14.7 

psia for all Subpart W equations used to quantify and report volumetric emissions for individual 

sources where gas volumes in those equations are already tracked in standard conditions. API

contends that converting gas volumes that are already tracked in standard conditions to actual 

conditions - just to satisfy the noted units convention for specific equations - only adds burden 

and no value to the reported information. The following equations have not been corrected and 

indicate that the resulting volumetric emissions are at actual conditions: 

 Equation W-3 (for AGR units) – In practice, the term Vs is tracked by industry in gas 

volume at standard conditions. 

 Equation W-4 (for AGR units) – In practice, the inlet and outlet flow rate are tracked at 

standard conditions. 

 Equation W-7 (well venting for liquids unloading) – In practice, the well venting flow 

rate will be measured at standard conditions. 

 Equations W-17 and W-18 (well testing venting and flaring) – In practice, the annual gas 

production rates and the gas terms in GOR values are based on standard conditions. 

 Equations W-19 and W-20 (flaring) – In practice, flared gas streams are tracked in 

standard conditions. 

 Equation W-39 (combustion) – In practice, the combusted gas streams are tracked in 

standard conditions.

In practice, all of the gas flow rates associated with the equations noted above are tracked in 

standard conditions. Requiring the calculation of gas volume emissions at actual conditions for 

the equations noted above only adds an unnecessary calculation step for the reporters. It would 

necessitate converting gas volume data, which is collected at standard conditions, to actual and 

then converting back to standard conditions under 98.233(t).

As it stands, many API member companies are tracking these emissions in volumes at standard 

conditions, which is permitted through the broad application of BAMM. None of the reporting 

requirements in 98.236 require reporting volumetric emissions, so the tracking of volumetric 

emissions as designated in the equations and then converting from actual volumes to standard 

volumes is not in the information reported to EPA and does not change the resulting emissions. 

As a result, API strongly insists that these equations be corrected such that they result in gas 

volumes in standard conditions – and not in actual conditions – since industry already tracks the 

gas volumes in standard conditions.

Response: EPA has considered this comment, and concludes that it is out of scope with the 

technical corrections, clarifying, and other amendments to certain provisions of the GHG 

Reporting Rule. As explained in section I.D. How do These Amendments Apply to 2012 Reports, 

in the preamble to the 2012 Technical Corrections final rule includes minor corrections and 
26

clarifications to certain provisions in the final rule that, while important to allow reporters to 

calculate emissions accurately, do not materially affect the actions facilities must take to comply 

with the rule. Several of the Equations that would be affected by the change suggested by the 

commenter were not opened for comment during the 2012 Technical Corrections proposed rule 

(77 FR 29935). EPA would like to note that reporters who are facing unique or unusual 

circumstances as defined in 40 CFR 98.234(f)(4), resulting from these identified issues may

apply for BAMM. As such, the changes proposed by the commenter go beyond that of this 

action. EPA is, however, considering this and other changes suggested by the commenters for 

inclusion in a future rulemaking. 

Commenter Name: Lisa Beal

Commenter Affiliation: Interstate Natural Gas Association of America (INGAA).

Document Control Number: EPA-HQ-OAR-2011-0147-0047

Comment Excerpt Number: 4

Comment: Nomenclature 

The difference in subsection numbering for §§ 98.233(o) and (p) identifies another technical 

correction that should be considered at some point. For example, the unique mode-source 

combinations are presented in § 98.233(o)(1)(i)-(iii) for centrifugal units and § 98.233(p)(1)-(3) 

for reciprocating units. These two sections include analogous requirements but do not 

consistently present the information and requirements in the same manner. To facilitate 

regulatory interpretation, these two sections should strive for consistency in their language, 

equations, parameter definitions, etc., whenever possible. 

Response: EPA has considered this comment, and concludes that it is out of scope with the 

technical corrections, clarifying, and other amendments to certain provisions of the GHG 

Reporting Rule. As explained in section I.D. How do These Amendments Apply to 2012 Reports, 

in the preamble to the 2012 Technical Corrections final rule includes minor corrections and 

clarifications to certain provisions in the final rule that, while important to allow reporters to 

calculate emissions accurately, do not materially affect the actions facilities must take to comply 

with the rule. As such, the changes proposed by the commenter are outside of the scope of this 

rulemaking. EPA is considering addressing the concerns raised by the commenter in a future 

rulemaking or through guidance posted on the subpart W website: 

http://www.epa.gov/climatechange/emissions/subpart/w.html. 

Commenter Name: Lisa Beal

Commenter Affiliation: Interstate Natural Gas Association of America (INGAA).

Document Control Number: EPA-HQ-OAR-2011-0147-0047

Comment Excerpt Number: 6

Comment: Content of methane and CO2 in natural gas: nomenclature 

The parameters that define methane and CO2 content also do not use consistent nomenclature. 

Throughout Subpart W, “GHGi” is used to define the concentration of gas “i” (i.e., methane or 

CO2). However, in Equation W-22 and Equation W-26, another term, “Mi,m”, is used to define 
27

GHGi. This inconsistency is unwarranted and GHGi should be used consistently in the 

equations. 

Response: EPA has considered this comment, and concludes that it is out of scope with the 

technical corrections, clarifying, and other amendments to certain provisions of the GHG 

Reporting Rule. As explained in section I.D. How do These Amendments Apply to 2012 Reports, 

in the preamble to the 2012 Technical Corrections final rule includes minor corrections and 

clarifications to certain provisions in the final rule that, while important to allow reporters to 

calculate emissions accurately, do not materially affect the actions facilities must take to comply 

with the rule. As such, the changes proposed by the commenter are outside of the scope of this 

rulemaking. EPA is considering addressing the concerns raised by the commenter in a future 

rulemaking or through guidance posted on the subpart W website: 

http://www.epa.gov/climatechange/emissions/subpart/w.html. 

Commenter Name: Lisa Beal

Commenter Affiliation: Interstate Natural Gas Association of America (INGAA).

Document Control Number: EPA-HQ-OAR-2011-0147-0047

Comment Excerpt Number: 8

Comment: Additional equation corrections are necessary for consistency. 

As discussed above, consistency between §§ 98.233(o) and (p) is warranted unless there is a 

sound reason for a difference. For centrifugal units, Equation W-22 includes the term “1-Bm” to 

address control via vapor recovery, flaring etc. For reciprocating units (and other source types in 

§ 98.233), the analogous equation does not include this parameter. Instead, § 98.233(p)(8) 

addresses vapor recovery for reciprocating compressors. For consistency, INGAA recommends 

deleting the “1-Bm” term from Equation W-22 and adding a subsection analogous to § 

98.233(p)(8) to § 98.233(o).

Response: For a response to this comment please see EPA response to comment EPA-HQ-OAR2011-0147-0047 - 7.

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 10

Comment: EPA has changed “high heat value” to “higher heating value” in 98.233(z)(2)(vi). 

API appreciates this revision, but requests that all uses of “high heat value” be similarly changed 

to “higher heating value” throughout Subpart W.

Response: EPA has considered this comment, and concludes that it is out of scope with the 

technical corrections, clarifying, and other amendments to certain provisions of the GHG 

Reporting Rule. As explained in section I.D. How do These Amendments Apply to 2012 Reports, 

in the preamble to the 2012 Technical Corrections final rule includes minor corrections and 

clarifications to certain provisions in the final rule that, while important to allow reporters to 
28

calculate emissions accurately, do not materially affect the actions facilities must take to comply 

with the rule. As such, the changes proposed by the commenter are outside of the scope of this 

rulemaking. EPA is considering addressing the concerns raised by the commenter in a future 

rulemaking or through guidance posted on the subpart W website: 

http://www.epa.gov/climatechange/emissions/subpart/w.html. 

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 11

Comment: The Subpart W rule has one calculation category, §98.233(f) Well venting for liquids 

unloadings, and one calculation methodology, Calculation Methodology 1, that has an equation, 

Equation W-7, where the time term, Tp, requires cumulative amount of time in hours of venting 

during the year. This time term appears to require identifying the total vent time from January 1st 

to December 31st of the reporting year. The reporting requirements for this category, 

§98.236(c)(5)(i)(C) also requires the cumulative number of unloading events that are vented to 

the atmosphere. In a common venting scenario described in the example below, it is not 

logistically possible to obtain the vent hours or number of unloading events from January 1st to 

December 31st of a reporting year, and the rule does not currently provide provisions such as: 

“Average estimated time that venting occurs in a year, using engineering estimate based on best 

available data” that other calculations, (Eq. W-31), allow; or annualization of the data, i.e. use of 

365 days of data that includes some data from the end of the previous year.

Example: Liquids Unloading Data Gathering and Reporting Scenario 

 A plunger lift well captures vent events and vent times via a local (wellsite) controller 

that does not electronically forward the data to the office or a database and does not have 

the capability to date stamp the vent event and vent times. 

 A field operator has to download the vent event and vent time data from the local 

controller at the wellsite for uploading into a database. 

 It is logistically impossible to gather the information from the local controllers in the field 

in one day, i.e. January 1st or December 31st. 

 The local controller data for all wells with these types of controllers is captured over a 

several week period by the field operators, normally in the 4th quarter. 

 The actual data gathered is normally for a time period other than 365 days, i.e. 300 – 400 

day period actually recorded by the local controller and downloaded by the field operator, 

due to weather, week-ends, holidays and other operational duties. 

 The data captured will normally span two annual reporting periods, i.e. November, 2011 

– November, 2012. 

As long as BAMM is allowed, the above situation is not an issue. However, after June 30, 2012, 

the rule as currently written creates a reporting issue for this situation. Unless the rule language 

is revised to allow for annualization of the data for the time period of January 1st to December 

31st using best available data from a time period other than January 1st to December 31st, the 

scenario described above will require an annual BAMM request to address the issue as it is our 

understanding that permanent BAMM requests are not allowed. 
29

This could potentially be addressed under the missing data procedures. Section 98.235 indicates 

that for continuously measured data, the reporter may use best available data for the emissions 

determinations. In addition, 98.235 requires “where missing data procedures are used for the 

previous year, at least 30 days must separate emissions estimation or measurements for the 

previous year and emissions estimation or measurements for the current year of data collection.” 

It is not clear if the missing data procedures would apply to tracking hours of venting.

API stipulates that there are three potential remedies outside of annual BAMM requests for this 

situation, and urges EPA to either adopt one of them or allow any of the three options: 

1. EPA could confirm that the missing data procedures would be used for tracking hours 

of venting; 

2. EPA could modify the rule language to allow the use of an average estimated time that 

venting occurs in a year, using engineering estimate based on best available data, such as 

is provided in other calculations (e.g., Equation W-31); or 

3. EPA could modify the rule language to allow reporters to compute an annualized 

estimate based on data that are collected. For example, apply 365 days of data even 

where the data span more than or less than one calendar year (from January 1st through 

December 31st). 

Response: EPA has considered this comment, and concludes that it is out of scope with the 

technical corrections, clarifying, and other amendments to certain provisions of the GHG 

Reporting Rule. As explained in section I.D. How do These Amendments Apply to 2012 Reports, 

in the preamble to the 2012 Technical Corrections final rule includes minor corrections and 

clarifications to certain provisions in the final rule that, while important to allow reporters to 

calculate emissions accurately, do not materially affect the actions facilities must take to comply 

with the rule. As such, the changes proposed by the commenter are outside of the scope of this 

rulemaking. EPA is considering addressing the concerns raised by the commenter in a future 

rulemaking or through guidance posted on the subpart W website: 

http://www.epa.gov/climatechange/emissions/subpart/w.html. 

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 12

Comment: What does EPA mean by “...and CO2 EOR” in the following definition of Facility

for onshore petroleum and natural gas production. See the excerpt below. 

Section 98.238 - Definitions 
30

Facility with respect to onshore petroleum and natural gas production for purposes of 

reporting under this subpart and for the corresponding subpart A requirements means all 

petroleum or natural gas equipment on a single well-pad or associated with a single 

well-pad and CO2 EOR operations that are under common ownership or common control 

including leased, rented, or contracted activities by an onshore petroleum and natural 

gas production owner or operator and that are located in a single hydrocarbon basin as 

defined in § 98.238. Where a person or entity owns or operates more than one well in a 

basin, then all onshore petroleum and natural gas production equipment associated with 

all wells that the person or entity owns or operates in the basin would be considered one 

facility.

For clarification, API requests that EPA modify the definition of facility provided above to 

replace “and CO2 EOR operations” with “or associated with CO2 EOR operations.”

Response: For the response to this comment, please see the response to comment EPA-HQOAR-2011-0147-0050 - 10. Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 13

Comment: The reporting requirements under 98.236(d) require the following: 

Report annual throughput as determined by engineering estimate based on best available data 

for each industry segment listed in paragraphs (a)(1) through (a)(8) of this section. 

Although these requirements were not revised in the December 23, 2011 or May 21, 2012 

amendments, API requests clarification on what value or values EPA is requesting. For example, 

for a gas processing plant, is throughput based on the inlet or outlet plant flow?

Response: EPA has considered this comment, and concludes that it is out of scope with the 

technical corrections, clarifying, and other amendments to certain provisions of the GHG 

Reporting Rule. As explained in section I.D. How do These Amendments Apply to 2012 Reports, 

in the preamble to the 2012 Technical Corrections final rule includes minor corrections and 

clarifications to certain provisions in the final rule that, while important to allow reporters to 

calculate emissions accurately, do not materially affect the actions facilities must take to comply

with the rule. As such, the changes proposed by the commenter are outside of the scope of this 

rulemaking. EPA is considering addressing the concerns raised by the commenter in a future 

rulemaking or through guidance posted on the subpart W website: 

http://www.epa.gov/climatechange/emissions/subpart/w.html. 

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 14

Comment: The pressure term SPp in Equation W-8 is defined as: 
31

Shut-in pressure or surface pressure for wells with tubing production and no packers or 

casing pressure for each well, p, in pounds per square inch absolute (psia) or casing-totubing pressure ratio of one well from the same sub-basin multiplied by the tubing 

pressure of each well, p, in the sub-basin, in pounds per square inch absolute (psia) 

This appears to require use of casing pressure or casing-to-tubing pressure ratio for wells with 

packers. However, the casing pressure is irrelevant for wells with packers. This is illustrated in 

the following diagrams. [See Docket Id. No EPA-HQ-OAR-2011-0147-0050 for diagrams 

provided by commenter.]

API requests that EPA modify the definition of SPp to allow the use of shut-in pressure or 

surface pressure for wells with packers. API’s proposed modification to the rule language is 

indicated below . . . 

SPp= Shut-in pressure or surface pressure for wells with tubing production and no 

packers or casing pressure for each well with no packers, p, in pounds per square inch 

absolute (psia), or casing-to-tubing pressure ratio of one well with no packer from the 

same sub-basin multiplied by the tubing pressure of each well, p, in the sub-basin, in 

pounds per square inch absolute (psia).

Response: EPA has considered this comment, and concludes that it is out of scope with the 

technical corrections, clarifying, and other amendments to certain provisions of the GHG 

Reporting Rule. As explained in section I.D. How do These Amendments Apply to 2012 Reports, 

in the preamble to the 2012 Technical Corrections final rule includes minor corrections and 

clarifications to certain provisions in the final rule that, while important to allow reporters to 

calculate emissions accurately, do not materially affect the actions facilities must take to comply 

with the rule. As such, the changes proposed by the commenter are outside of the scope of this 

rulemaking. EPA is considering addressing the concerns raised by the commenter in a future 

rulemaking or through guidance posted on the subpart W website: 

http://www.epa.gov/climatechange/emissions/subpart/w.html. 

Commenter Name: Karin Ritter

Commenter Affiliation: American Petroleum Institute (API)

Document Control Number: EPA-HQ-OAR-2011-0147-0050

Comment Excerpt Number: 15

Comment: There is a minor edit needed in paragraph (G) 98.236(c)(6) for well completions. 

(G) Report number of completions employing purposely designed equipment that 

separates natural gas from the backflow and the amount of natural gas, in standard cubic 

feet, recovered using engineering estimate based on best available. 
32

(H) Report number of workovers employing purposely designed equipment that separates 

natural gas from the backflow and the amount of natural gas, in standard cubic feet, 

recovered using engineering estimate based on best available data. 

It appears paragraphs (G) is truncated, "best available" should be "best available data" to be 

consistent with paragraph (H).

Response: EPA has considered this comment, and concludes that it is out of scope with the 

technical corrections, clarifying, and other amendments to certain provisions of the GHG 

Reporting Rule. As explained in section I.D. How do These Amendments Apply to 2012 Reports, 

in the preamble to the 2012 Technical Corrections final rule includes minor corrections and 

clarifications to certain provisions in the final rule that, while important to allow reporters to 

calculate emissions accurately, do not materially affect the actions facilities must take to comply 

with the rule. As such, the changes proposed by the commenter are outside of the scope of this 

rulemaking. EPA is considering addressing the concerns raised by the commenter in a future 

rulemaking or through guidance posted on the subpart W website: 

http://www.epa.gov/climatechange/emissions/subpart/w.html. 

Commenter Name: Pamela Lacey

Commenter Affiliation: American Gas Association

Document Control Number: EPA-HQ-OAR-2011-0147-0048

Comment Excerpt Number: 2

Comment: Count Just Leaking Components vs. Total Number of ALL Components.

The 2012 Proposed Technical Corrections does not correct or clarify the confusing provisions in 

the inter-related calculations under Equations W-30B, W-31 and W-32. These provisions could 

be interpreted to imply that an LDC must count ALL components (including non-leakers) at all 

stations, rather than simply counting leaking components and applying the default leaker 

emission factors. 

Our members do not maintain inventories of all their components everywhere. If the rule indeed 

were interpreted to require providing a count of all components – both leaking and non-leaking, 

our members would have to devote significant employee time to go to each T-D station to count 

all the components. This would be an exceedingly burdensome requirement that would not 

produce any useful data. The point of the rule is to report emissions, not the absence of 

emissions. It makes no sense to require utilities to count all components in their T-D stations, 

whether leaking or not. We do not believe this was your intent, but the rule should be clarified to 

make your intent clear. This problem could be fixed in the Technical Corrections Rule by adding 

a qualifier to clarify that the LDC doing a leak survey at a Transmission to Distribution (T-D) 

station should count components “found to be leaking.” Thus, in Equation W-30B under section 

98.233(q), clarify that “x = total number of each component type found to be leaking.” In

addition, there is confusion about the conflicting references to emissions and population counts 

of “component types” vs. meter/regulator runs in Equation W-31 under section 98.233(r). For 
33

other Subpart W facilities, the equation may make sense, but for distribution facilities (i.e. a gas 

utility’s statewide network of metering-regulating stations), the equation is supposed to multiply

a population count of above-grade metering-regulating stations by the station-level, companyspecific emission factor developed in Equation W-32. 

References to counting population counts of “component types” or to the average estimated time 

that “each component type associated with the equipment leak emission was operational” makes 

no sense in this context. More importantly, mixing up component counts and meter/regulator run 

counts will cause the equation to implode. It simply will not compute. This is a clear error in the 

rule that really must be corrected in the 2012 Technical Corrections so that Local Distribution 

Companies (LDCs) can submit the reports due by September 28, 2012. We think you will agree 

that such a fix would be one for which comment is both "unnecessary" and "Impracticable" 

under the Administrative Procedure Act. 

The current state of the equations serves no conceivable regulatory purpose, and the change is 

needed to achieve what we are confident was EPA's original intent. Moreover, it must be made 

quickly to remove a requirement to use equations that simply will not work for this reporting 

year. 

One way to make this correction could be to define “component type” for purposes of natural gas 

distribution under Equation W-31 to mean the “meter/regulator run.” Another solution, which we 

would prefer, would be to create an Equation W-31A and W-31B, with the latter designed for 

natural gas distribution facilities only that would clearly explain that LDCs should apply the 

meter/regulator run-level emission factor developed in Equation W-32 to a population count of 

meter/regulator runs at above-grade metering-regulating stations. We would be happy to work 

with EPA to ensure that the revised equations are functional and clear.

Response: EPA has considered this comment, and concludes that it is out of scope with the 

technical corrections, clarifying, and other amendments to certain provisions of the GHG 

Reporting Rule. As explained in section I.D. How do These Amendments Apply to 2012 Reports, 

in the preamble to the 2012 Technical Corrections final rule includes minor corrections and 

clarifications to certain provisions in the final rule that, while important to allow reporters to 

calculate emissions accurately, do not materially affect the actions facilities must take to comply 

with the rule. As such, the changes proposed by the commenter are outside of the scope of this 

rulemaking. EPA is considering addressing the concerns raised by the commenter in a future 

rulemaking or through guidance posted on the subpart W website: 

http://www.epa.gov/climatechange/emissions/subpart/w.html. 
34

IV. Comments on the Proposed Amendments and Confidentiality 

Determinations for Subpart L

Comments on the Methods Used to Determine Global Warming Potentials for Fluorinated 

Greenhouse Gases Reported under Subpart L

Commenter Name: Dana Schnobrich

Commenter Affiliation: 3M Company

Document Control Number: EPA-HQ-OAR-2011-0147-0044

Comment Excerpt Number: 2

Comment: EPA has also requested comment on 98.126(j) Special Provisions for Reporting 

Years 2011 and 2012 Only. This new section addresses methods that can be used to calculate the 

total site emissions of all fluorinated-GHG’s [sic], in metric tons of CO2e, from all processes 

that are subject to Subpart L for the periods specified. 3M supports the methodologies that are 

being proposed by EPA with one clarification. Proposed Section 98.126(j)(3) provides for the 

use of a “best estimate” of GWP based on the methods described in Section 

98.123(c)(1)(vi)(A)(3). 3M asks that EPA clarify that comparable methods based on use of 

professional judgment are acceptable, as discussed in more detail below.

3M has had considerable experience in calculating and estimating GWP. As indicated in 

previous communications on this rulemaking, 3M has completed a corporate-wide GHG 

inventory annually since 2002. The GHG inventory data has been used for participation in many

climate and sustainability related programs such as the EPA Climate Leaders program, 3M 

Corporate Sustainability reporting, and the Dow Jones Sustainability Index. The inventory

follows the World Resources Institute (WRI) protocol and has been validated in two rigorous 

external third party audits using EPA-approved auditors. As a part of this program 3M has 

developed formal procedures to determine GWP’s [sic] where this information does not exist in 

the scientific literature. The fluorochemical production related emissions portion of the 3M 

inventory was used to draft Chapter 3.10 of the Intergovernmental Panel on Climate Change’s 

(IPCC) 2006 National GHG reporting Guidelines. As part of the preparation of these guidelines, 

this section underwent significant technical peer review prior to publication. The reviewers 

included international GHG technical experts and representative from EPA.

With respect to “best estimates” of GWP, the proposed rule calls for using either a default GWP 

or a best estimate of GWP based on the information described in Section 98.123(c)(1)(vi)(A)(3). 

That section lays out various forms of data and analysis that support estimates of GWP, 

including among other data, “(i) data and analysis related to the low-pressure gas phase infrared 

absorption spectrum of the fluorinated GHG . . .” In 3M’s experience in estimating GWP, this 

data and analysis may be useful in making the best estimate of GWP. In other situations, 

however, where pure standards of a compound are not available, an analysis of the infrared 

spectrum for a specific fluorinated GHG is not possible. In these cases 3M has determined the 

radiative forcing of such chemicals based on professional judgment which would normally

include the use of quantitative structure activity relationships (QSAR’s) that relate 

mathematically, the radiative forcing of a compound to the chemical’s structure (i.e., type of 

compound (HFC vs. PFC), number of carbon-halogen bonds, etc.). 3M believes that this is a 
35

valid approach to performing a “best estimate” in this situation and that this is consistent with the 

methods that are described in Section 98.123(c)(1)(iv)(A)(3). 

The following is additional detail on why it may be difficult to obtain an IR spectrum for a 

compound. In order to determine the radiative forcing of a compound, a gas phase IR spectrum 

of the compound at a known concentration is required. Therefore to make such an IR spectrum 

an analytical standard of this “target” compound must be available. For this standard either (1) 

the “target” compound must be pure; or (2) if the compound is not pure, the purity of standard 

must be known and the FTIR spectra of each of the individual impurities must be available so 

that their influence on the radiative forcing of the target compound can be removed. In many 

gaseous manufacturing emission streams, some compounds (primarily by-products) may be 

present for which pure standards are not commercially available, and these compounds cannot be 

isolated at high purity from the manufacturing gas stream to prepare standards. This is why it is 

difficult to obtain spectra of some compounds. 

The IPCC states that the GWPs listed in the IPCC Assessment Report have an uncertainty of 

35%. 3M has conducted comparisons between measured and QSAR derived GWPs. Based on 

this approach the uncertainty of the radiative forcings associated with QSAR-derived GWPs is 

estimated to be 18 to 23%. For the atmospheric lifetimes on average for a given class of 

compounds, the QSAR estimates of the atmospheric lifetime differ from measured values by 

30% with some minor exceptions. The overall uncertainty of a QSAR-based GWP is therefore a 

combination of these tow uncertainties, and use of QSARs is still more accurate than the default 

GWPs of 2,000 or 10,000 that are provided in the proposed rule. Use of the QSAR method is 

much more accurate than using the proposed default GWPs for certain compounds in classes 

where there is more measured data – in those situations, use of the QSAR method may result in a 

GWP that is not much different from a measured GWP.

Accordingly, 3M asks that EPA clarify that estimating the radiative forcing of chemicals based 

on professional judgment is an acceptable methodology for making a best estimate of GWP, in 

situations in which the pure standards of a compound are not present.

The above is just one example of a methodology that is based on professional judgment but may

not be specifically described in or captured by the subsections contained in Section 

98.123(c)(1)(iv)(A)(3). Other methodologies based on use of professional judgment may be 

acceptable. 3M asks EPA to clarify that other methods relying on use of professional judgment 

are acceptable, if they result in accuracy that is comparable to the accuracy associated with the 

methods described in Section 98.123(c)(1)(iv)(A)(3). 

Response: As explained in Section II.D.2 of the final preamble, we are finding the use of 

QSARs to be acceptable in this context. However, we disagree with the commenter’s 

recommendation that the rule be revised to state that any comparable methods based on use of 

professional judgment are acceptable if they result in accuracy that is comparable to the accuracy

associated with the methods described in §98.123(c)(1)(vi)(A)(3). The commenter did not 

address how alternative methods would be determined to have comparable accuracy. One 

approach would be to allow reporters to make this determination. However, this approach could 

result in a wide range of GWPs being used for the same chemical as individual reporters made 
36

their own independent judgments of which alternative methods possessed “comparable 

accuracy.” It would also introduce greater uncertainty in interpreting the reported CO2e 

emissions since the accuracy of the CO2e emissions would be unknown for those facilities that 

employed an alternative approach for determining GWPs. In general, rather than allowing 

facilities to estimate emissions using their own calculation methods, EPA has specified methods 

for estimating GHG emissions throughout the GHG Reporting Rule. This is to ensure that 

estimates are acceptably accurate and comparable across facilities (see, for example, the 

discussion at 74 FR 56279). 

Another approach would be for the EPA to make the determination of whether an alternative 

method possessed comparable accuracy. However, this approach would likely be time 

consuming and cumbersome to the Agency, as well as to reporters, who would be required to 

submit detailed information on their alternative methods to the EPA in advance of the reporting 

deadline. In fact, the proximity of the deadline for reporting 2011 emissions (September 28, 

2012) would render this approach impractical for the first year of reporting. We believe that 

allowing the QSAR approach addresses the specific concerns expressed by this commenter and 

provides sufficient flexibility without introducing additional complexity for reporters. Thus, we 

are not including a blanket provision permitting use of comparable methods based on 

professional judgment. 

Comments on the Proposal to Report Emissions at the Facility-Level for Year 2011 and 2012 

Commenter Name: Dana Schnobrich

Commenter Affiliation: 3M Company

Document Control Number: EPA-HQ-OAR-2011-0147-0044

Comment Excerpt Number: 1

Comment: 3M very much appreciates EPA’s consideration of our previous comments on 

EPA’s GHG Mandatory Reporting Rule, Subpart L, and related confidentiality determinations. 

We have reviewed the proposed technical corrections for those sections of the document that 

discuss Subpart L and we concur with these modifications that are being proposed by EPA. 3M 

supports the deferral for reporting of those data elements that are contained in 40 CFR 

98.3(c)(4)(iii) and 40 CFR 98.126(a)(2), (a)(3), (a)(4), (a)(6), (b), (c), (d), (e), (f), (g), and (h). 

These data elements adequately capture that information that may be subject to export control 

and/or which may contain confidential business information. 3M also supports EPA’s Subpart L 

proposal to require reporting on a facility-wide basis of fluorinated GHGs emissions, expressed 

in metric tons of CO2e, for both 2011 and 2012. This period will allow for time that may be 

necessary to resolve confidentiality and/or export control issues. In addition, with the 

requirement for reporting on a facility-wide basis and the use of best estimates for GHGs, EPA 

will be receiving annual total facility-wide fluorinated GHG emission during this time period, 

expressed in tons of CO2e.

. . .

The preamble of the rule and referenced document, “Memorandum: Potential Future Subpart L

Options”, discuss different options that EPA may be considering for reporting years beyond 2011 
37

and 2012. 3M understands that EPA is not requesting comments on these activities at this time, 

but we anticipate participating in further discussions with EPA on this very important issue. 

Response: The EPA thanks the commenter for their input. The EPA has amended subpart L as 

proposed in the May 21, 2012 notice; therefore, facilities subject to subpart L are not required to 

report the data elements 40 CFR 98.3(c)(4)(iii), 98.126(a)(2)-(4), 98.126(a)(6), and 98.126(b)-(h) 

until the later of March 31, 2014 or the date set forth for that data element at §98.3(c)(4)(vii) and 

Table A-7 of Subpart A . As we noted in the preamble to the proposed rule, the EPA received 

comment from the 3M Company and the American Chemistry Council indicating concern that 

the disclosure of the identity and quantities of fluorinated GHG emissions at the process level, 

from either process vents or fugitive sources, would reveal sensitive information regarding 

individual chemical production processes. The EPA is currently evaluating these concerns and 

published a Memorandum: Potential Future Subpart L Options (see EPA-HQ-OAR-2011-0147-

0039) outlining some possible alternative options when this action was proposed on May 21, 

2012. Any long-term changes to Part 98 would be made through a separate regulatory action in 

which the public would be afforded an opportunity to comment on the proposed changes. 

Commenter Name: Brendan Mascarenhas

Commenter Affiliation: American Chemistry Council (ACC)

Document Control Number: EPA-HQ-OAR-2011-0147-0049

Comment Excerpt Number: 1

Comment: ACC appreciates the Agency’s consideration of our March 2012 comments on EPA’s 

January 2012 “Proposed Confidentiality Determinations for Data Elements Under the Mandatory

Reporting of Greenhouse Gases Rule (MRR).”2 In those comments, ACC raised specific 

concerns with the proposed determinations for data elements under Subpart L, Fluorinated Gas 

Production. ACC and its member companies are concerned that the disclosure of the identity and 

quantities of the fluorinated GHGs emitted at the process level, from either process vents or as 

fugitive emissions, would reveal sensitive information regarding individual chemical production 

processes. As process-level information can contain specific information on reactants,

byproducts, and products, requiring the disclosure of this data as an input to emissions equations 

(thereby rendering the information ineligible for treatment as confidential business information) 

could place manufacturers at a competitive disadvantage. 

For these reasons, ACC appreciates and supports EPA’s proposal for a new reporting element for 

reporting years 2011 and 2012, “where owners and operators of facilities producing fluorinated 

gases would be required to report annual total facility-wide fluorinated GHG emissions”3 

expressed in metric tons of carbon dioxide equivalent (CO2e). This method maintains accurate 

GHG emission reporting while removing the threat of disclosing confidential business 

information (CBI). ACC agrees with EPA that this amendment would also allow the Agency

sufficient time to evaluate and resolve any current confidentiality concerns. 

ACC also agrees with EPA’s deferral of reporting specific Subpart L data elements4until March 

31, 2014. This decision represents EPA’s recognition of the unique sensitivities present in 

reporting under Subpart L. It is appropriate to postpone reporting of these elements to the given 

date and provide adequate time for the Agency to resolve potential issues and further establish a 

representative and responsible reporting program. ACC also supports of EPA’s decision to defer 
38

the reporting of data elements that are inputs to emissions equations, including those from 

Subpart L, to March 31, 2015. 

ACC is encouraged by EPA’s May 10, 2012 memorandum detailing potential future Subpart L 

options. Although ACC understands that the Agency is not currently requesting comment on the 

possible changes presented in the memorandum at this time, we look forward to collaborating 

closely with EPA in the near future to determine the most appropriate reporting option.

Response: Please see the response to comment EPA-HQ-OAR-2011-0147-0044, excerpt 1 

above.

Commenter Name: Robert Reich

Commenter Affiliation: DuPont Company

Document Control Number: EPA-HQ-OAR-2011-0147-0051

Comment Excerpt Number: 1

Comment: DuPont is concerned that the disclosure of the identity and quantities of the 

fluorinated

GHGs emitted at the process level, from either process vents or fugitive sources, would reveal 

sensitive information regarding individual chemical production processes. As process-level 

information can provide significant insight into reactants, byproducts, and products, requiring the 

disclosure of this data as inputs to emissions equations (and thus making it ineligible for 

treatment as confidential business information) could place U.S. manufacturers, such as DuPont, 

at a competitive disadvantage with their overseas competitors. As we have expressed in prior 

comments [footnote: DuPont Response to EPA Call for Information: Information on Inputs to 

Emission Equations Under the

Mandatory Reporting of Greenhouse Gases Rule; 40 CFR Part 98. For submittal to EPA Docket 

#: EPA–

HQ–OAR–2010–0964, March 7, 2011], we are not particularly averse to providing the 

information to EPA provided it is understood to be confidential business information (CBI) and 

managed by the Agency in a manner consistent with such classification. Of course, we are 

concerned about any of our CBI being managed outside of our own control, and therefore urge 

EPA to consider carefully the need for receiving such information as compared with the more 

relevant overall GHG emissions, provided that the facility maintains records of the specific FGHGs and their quantities, subject to EPA inspection.

DuPont supports EPA’s proposal for a new reporting element for reporting years 2011 and 2012, 

which would require manufacturers of fluorinated gases to report annual total facility-wide 

fluorinated GHG emissions, expressed in metric tons of carbon dioxide equivalent (CO2e). This 

method maintains accurate GHG emission reporting while removing any threat of disclosing 

potential CBI. Such an amendment would also allow the Agency sufficient time to evaluate and 

resolve confidentiality concerns. 

DuPont also supports the Agency’s proposal to defer reporting specific Subpart L data elements 

[footnote: 40 CFR 98.3(C)(4)(iii) and 40 CFR 98.126(a)(2)(a)(3), (a)(4), (a)(6), (b), (c), (d), (e), 

(f), (g), and (h)] until March 31, 2014, and we again express our support for EPA’s decision to 
39

defer the reporting of data elements that are inputs to emissions equations, including those from 

Subpart L, to March 31, 2015.

In reference to Subpart L, but perhaps of a more generic nature, we note with some concern a 

statement in the preamble of the proposal that opens: “Because only one company raised 

concerns that reporting process-specific emissions by chemical would reveal trade secrets...” In 

this case, the American Chemistry Council (ACC), of which DuPont and several other 

fluorinated gas producers are members, had represented our industry in its comments submitted 

on March 12, 2012, in reference to the confidentiality concerns with respect to the reporting of 

process-specific emissions of fluorinated gases. DuPont felt that these comments adequately 

expressed our concerns and that the additional resource expenditure to prepare separate 

comments was not warranted. We anticipate using the same rationale in deciding whether 

separate comments are needed for future regulatory proposals and hope EPA recognizes that 

ACC and other trade organization comments typically represent their member companies unless 

otherwise stated.

Response: Please see the response to comment EPA-HQ-OAR-2011-0147-0044, excerpt 1 

above. With respect to the comment on trade organizations, the EPA recognizes that comments 

submitted by trade organizations represent the concerns of members. We also acknowledge the 

commenter’s support for comments previously submitted by the American Chemistry Council 

regarding the sensitivity of some subpart L data elements. 

Commenter Name: Joel Hall

Commenter Affiliation: Mexichem Fluor, Inc.

Document Control Number: EPA-HQ-OAR-2011-0147-0045

Comment Excerpt Number: 1

Comment: Mexichem supports the proposal to allow facilities subject to Subpart L to report 

greenhouse gas emission data in a less detailed manner for reporting years 2011 and 2012 in 

order to allow EPA time to fully evaluate concerns raised by stakeholders that reporting and 

subsequent EPA release of certain data would reveal trade secrets. Mexichem was unable to 

provide comments on the January 10, 2012 proposed rule regarding confidentiality

determinations. Nonetheless, we share similar concerns with 3M in that reporting and subsequent 

release of some of the data under Subpart L could give competitors insight into our 

manufacturing process and thereby allow them to duplicate our process without incurring 

research and development costs. This would place us at a distinct competitive disadvantage. 

We have previously raised concerns with the confidentiality of “emission data” required to be 

reported under Subpart L (see our Comments on Proposed Confidentiality Determinations for 

Data Required Under the Mandatory Greenhouse Gas Reporting Rule and Proposed Amendment 

to Special Rules Governing Certain Information Obtained Under the Clean Air Act and the 

Proposed Confidentiality Determinations for Data Required Under the Mandatory Greenhouse 

Gas Reporting Rule, Docket ID No. EPA-HQ-OAR-2009-0924). 

Most concerning for us is data required to be reported under 40 CFR 98.126(a)(3) and (a)(4). 40 

CFR 98.126(a)(3) requires reporting of, “The chemical identities of the contents of the stream(s) 
40

(including process, emissions, and destroyed streams) analyzed under the initial scoping 

speciation of fluorinated GHG at §98.124(a), by process.” 40 CFR 98.126(a)(4) requires 

reporting of, “The location and function of the stream(s) (including process streams, emissions 

streams, and destroyed streams) that were analyzed under the initial scoping speciation of 

fluorinated GHG at §98.124(a), by process.” EPA has proposed that the data required to be 

reported under 40 CFR 98.126(a)(4) be considered confidential because it is in the ‘‘Unit/Process 

‘Static’ Characteristics That are Not Inputs to Emission Equations’’ data category. EPA states 

that this data is a basic facility-specific characteristic that does not vary with time or with the 

operations of the process and is not an input to an emission equation (77 FR 1442). Mexichem 

supports the EPAs proposal with respect to this data element and believes that the data required 

to be reported under 40 CFR 98.126(a)(3) should be afforded the same consideration. For the 

reasons stated above, and as the EPA has acknowledged with respect to the data to be reported 

under 40 CFR 98.126(a)(4), these data elements “could provide insight into the manufacturing 

process and the configuration of the facility, such as which process equipment is sending streams 

to which process equipment. This could reveal information about configuration efficiencies that 

the reporter has developed, generally at great expense and time investment, to minimize 

manufacturing cost and to maximize the manufacturing rate. If a competitor could review such 

information on configuration, the competitor would be able to adopt the reporter’s efficiency

practices with less development time and expense and would gain competitive advantage at the 

expense of the reporter’s competitive advantage.”

Response: The commenter appears to be responding to our proposed confidentiality

determinations for subpart L (77 FR 1434, January 10, 2012). Although we proposed 

confidentiality determinations for the subpart L data elements listed in 40 CFR 98.126(a)(3) and 

(a)(4), we are not making final determinations regarding these data elements at this time. We 

plan to address confidentiality determinations for these subpart L data elements through a 

separate future rulemaking. As part of this action, however, the EPA is deferring the reporting 

deadline for the following data elements: 40 CFR 98.3(c)(4)(iii), 98.126(a)(2)-(4), 98.126(a)(6), 

and 98.126(b)-(h) until the later of March 31, 2014 or the date set forth for that data element at 

§98.3(c)(4)(vii) and Table A-7 of Subpart A . The data elements mentioned by the commenter 

(40 CFR 98.126(a)(3) and (4)) are among those whose reporting is affected by today’s action. 

Deferring the reporting deadline for data elements 40 CFR 98.126(a)(3) and (4) addresses the 

commenter’s concerns in the short term and allows the EPA additional time to consider 

stakeholder concerns regarding the disclosure of subpart L data elements. Please see the 

response to comment EPA-HQ-OAR-2011-0147-0044, excerpt 1 above.