1

MEMORANDUM

FROM: Lisa Hanle, U.S. EPA, Climate Change Division

TO: Docket EPA-HQ-OAR-2011-0147, 2011 Technical Corrections, Clarifying and Other 

Amendments to Certain Provisions of the Mandatory Greenhouse Gas Reporting Rule.

DATE: May 12, 2011

SUBJECT: Summary of questions raised on various subparts of the final Mandatory

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

addressed in the proposed 2011 Technical Corrections, Clarifying and Other 

Amendments to Certain Provisions of the Mandatory Reporting of Greenhouse Gases 

Rule.

1.0 INTRODUCTION

The 2009 final GHG reporting rule (2009 final rule) was signed by EPA Administrator Lisa 

Jackson on September 22, 2009 and published in the Federal Register on October 30, 2009 (74 FR 

56260, October 30, 2009). The 2009 final rule, which became effective on December 29, 2009, 

included reporting of GHGs from various facilities and suppliers, consistent with the 2008 

Consolidated Appropriations Act. Subsequent notices were published in 2010 finalizing the 

requirements for subparts FF, II, and TT (75 FR 39736, July 12, 2010), subpart W (75 FR 74458, 

November 20, 2010), subpart DD (75 FR 74774, December 1, 2010), and subpart RR (75 FR 75060, 

December 1, 2010). Subpart OO, which was promulgated as part of the 2009 final rule was also 

revised in 2010 (75 FR 79092, December 17, 2010). These requirements are contained in 40 CFR part 

98.The rule does not require control of GHGs, rather it only requires that sources above certain 

threshold levels monitor and report emissions and other related data.

Since promulgation of the rule, the Administrator has identified a number of technical issues 

that need to be corrected and specific portions of the Mandatory Greenhouse Gases Reporting Rule 

(hereafter referred to as “Part 98”) that need to be clarified. EPA is proposing to amend specific 

provisions in Part 98 to correct those technical and editorial errors that have been identified since 

promulgation and to propose clarifying or other amendments to certain provisions that have been the 

subject of questions from reporting entities. 

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

98 and to summarize the questions that have been raised during EPA’s outreach activities that are 

being addressed by some of the proposed amendments. 

2.0 SUMMARY OF EPA OUTREACH ACTIVITIES

EPA has conducted an extensive outreach program for the Mandatory GHG Reporting Rule, 

including meetings with trade associations and individual businesses, on-line web-based seminars 

(webinars), and training sessions for EPA Regional Offices. The following table lists those meetings 
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and webinars that EPA has conducted to date, along with the month and year of the activity. When 

available, the table also includes the approximate attendance for the meeting or webinar.

POST-SIGNATURE MEETINGS AND WEBINARS

Month and Year of Information Meeting or Webinar

Organization or Location (estimated attendance, if available) 

Sept 2009

EPA Regional Offices Briefing (100)

Agriculture community teleconference (100)

State and Local Agencies teleconference (100)

Clean Energy Group Meeting (about 40)

State of Washington (2)

Business Council (73)

Call with Massachusetts on data system (2)

Overview webinar (293)

US Climate Action Partnership (20)

Overview webinar (284)

National Cooperative Refinery Association, and Van Arsdall & Associates

Oct 2009

Oil and Gas Compact (30)

Detailed webinar (326)

Portland Cement Assoc. (20)

CENSARA(50)

Overview webinar (217)

Applicability Tool Demonstration (84)

National Lime Assoc. (3)

Detailed webinar (252)

EEI (80)

NACAA (75)

Nitric Acid and Ammonia Assoc.(30)

TFI, AISI, SMA

Overview webinar (176)

Detailed webinar (208)

Air Program Managers and staff (25)

Detailed webinar (206)

Aluminum Industry 

Steel Manufacturers Assoc.

Natural Gas Star 

Overview webinar (133)

Carolina Air Pollution Control Assoc. (400)

Applicability Tool Demonstration (238)

Waste Management and Equipment Companies (25)

Ohio Manure Storage 

Overview webinar (251)

Corporate Climate Regulation, Chicago, IL

Midwest Transportation & Air Quality Conference 

Detailed webinar (333)
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POST-SIGNATURE MEETINGS AND WEBINARS

Month and Year of Information Meeting or Webinar

Organization or Location (estimated attendance, if available) 

TCR/CAA (90)

Environmental Groups (10)

API 

NOV 2009

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

Northeast Gas Assoc. 

Ecology and Environment, Inc. (2)

Detailed webinar (253)

TCR 

Tribal Air Coordinators (50)

GHG data exchange discussion with New Mexico (8)

API (20)

ABA (100)

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

State-EPA Dialogue - DC (80)

Treated Wood Council (60)

Detailed webinar (172)

MAPI (Manufacturing Alliance) (15)

Environmental Services Corporation (150)

Western Climate Initiative partner meeting – Santa Fe (50)

Detailed webinar (171)

Regional Climate sub-leads (40)

Air Products (5)

Waste Management and others (10)

Detailed webinar (96)

DEC 2009

AWMA-EPA- RTP (100)

Envirosys (4)

Detailed webinar (50)

ACC (5)

National Grid 

Detailed webinar (91)

Utilitpoint and Allegro (115)

CARB 

NPRA and API

Golder and Associates

Anadarko (10)

Kinder Morgan 

EEI 

SWANA- LFGTE 

Thermo Fisher Scientific 

EPA Region 4 Training (100)

Waste Management and others (8)

Air Products (5)
4

POST-SIGNATURE MEETINGS AND WEBINARS

Month and Year of Information Meeting or Webinar

Organization or Location (estimated attendance, if available) 

The Fertilizer Institute

ADM (8)

JAN 2010

Detailed webinar (83)

Air Products 

National Emissions Inventory (30)

OECA- Regional offices (30)

National Grid

Alliance of Automobile Manufacturers (9)

Detailed webinar (100)

NRPA (300)

Feb 2010

Dedicated webinar for American Colleges and Universities (220)

EPA Regional Inventory, Enforcement (23)

University Challenge

State webinar (200)

Webinar (182)

Iowa Landfill operators (125), Asphalt Paving Association of Iowa (70), and the Iowa Chapter of AMWA (60).

Mar 2010

Inst. Of Clean Air Companies (23)

SWANA (200)

EPA AFS Compliance Meeting 

Second Nature (Colleges/Universities) Panel (20)

ECOS (50)

PCA 

Training- EPA Regions 5 and 7 (180)

Iowa Landfills (50)

April 2010

Arkansas Environmental Federation, Little Rock (160)

NACAA Emissions and Modeling Committee (30)

Webinar (75)

Central TX AWMA (50)

Chicago Exchange Meeting

Exchange Network National Meeting (50)

EPA Air Division Directors (20)

National Assoc. of Clean Water Agencies

Pepsico-Frito Lay (150)

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

May 2010

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

ESC Users Group (150)

NCASI 

EPRI CEMUG (150)

June 2010

Webinar: Q&A Session (54)
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POST-SIGNATURE MEETINGS AND WEBINARS

Month and Year of Information Meeting or Webinar

Organization or Location (estimated attendance, if available) 

October 2010

e-GGRT Training (748)

e-GGRT Training (566)

November 2010

e-GGRT Training (521)

Webinar: Subpart FF (44)

General Stakeholder Call: Subparts RR and UU (88)

December 2010

EPA Regional Offices Briefing (20)

NACAA (50)

Webinar: Subpart I (71)

Webinar: Subpart W (481)

Webinar: Subparts RR and UU (77)

Webinar: e-GGRT and OTAQREG Training (386)

Webinar: Subpart W (130)

January 2011

Webinar: Subpart W (138)

Webinar: e-GGRT Training (512)

February 2011

Webinar: Overview (98)

EEI: Subpart RR

May 2011

Webinar: Overview

Webinar: Subpart OO

June 2011

Webinar: Overview

3.0 SUMMARY OF QUESTIONS FROM THE EPA HELPLINE AND TRADE

ASSOCIATIONS BEING ADDRESSED BY PROPOSED AMENDMENTS

EPA has maintained a web-based helpline that allows individuals to submit questions about

Part 98, including the additional subparts and rule amendments promulgated in 2010. So far, EPA has 

resolved approximately 2,300 inquiries on Part 98. Most of those inquiries have been resolved by 

providing further guidance to reporting entities through a web-based list of answers to frequently 

asked questions. However, several additional questions would be resolved through the 2011 proposed 

amendments to Part 98.

The EPA has also held meetings with several trade associations for industries affected by Part 

98, and many questions were presented by those trade associations that would be resolved through the 

2011 proposed amendments to Part 98.

The following table summarizes the questions that have been raised from the EPA helpline and 

trade associations on various subparts of Part 98 which are being addressed by the proposed 2011

technical corrections, clarifying and other amendments. Not all of the technical corrections and other 
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amendments correspond directly to questions that were raised by reporters. The need for some 

corrections and other amendments were identified as a result of internal EPA review stemming from 

reporter questions and may not be reflected in the following table. Any specific identifying

information from the incoming questions has been removed from the table below. 
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Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

Subpart A – General Provisions

Clarification under 98.5 

regarding which 

communications can be 

submitted through the 

electronic greenhouse gas 

reporting tool and what 

communications can be 

submitted through the 

mail to the Director of 

the Climate Change 

Division.

We have received an inquiry from a state regarding where to send reports 

required under Part 98 as companies are sending reports to our state agency. 

The State will hold any reports received until they have further instructions. 

There is not a designated contact on our Point of Contact list for the region.

At least 4

individuals

Helpline

To where and how is the Certificate of Representation sent? At 98.5 it says 

that it is to be submitted electronically. 98.9 only gives a mailing address.

Helpline

Under §98.5 of the GHG Rule it says that the Certificate of Representation is 

to be submitted electronically. Where and how is this to be done? The Final 

GHG Report is also to be submitted electronically, will facilities be notified of 

the procedures to follow for submission of the required information?

Helpline

What is the development status of EPA's electronic submission tool for the 

Part 98 greenhouse gas mandatory reporting rule (GHG MRR) [98.5]? When 

does EPA expect to have a version of reporting tool available for industry 

review? Will the tool include functionality to submit the "certification of 

representation" as described in 98.4(i)? Will the tool include functionality to 

submit the "notice of delegation" as described in 98.4(m)? Will the tool allow 

importing of data from spreadsheet templates or will it only accept data via 

manual population of web forms?

Helpline

An EPA regional representative received the attached report from a facility in 

the region for the GHG Reporting Rule. They must have not reviewed 98.9. 

Please let me know if this e-mail box is the correct location to send this to. 

Helpline

Which address should be used to submit a letter of notification of cessation 

of operations in accordance with 40 CFR 98.2(i)(3)?

Helpline
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Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

Amend the definition of 

"blowdown vent stack 

emissions" in 98.6 to add

the phrase “emissions 

from emergency events 

are not included”

The blowdown vent stack source category is defined in 98.6 as venting due 

to "maintenance and/or blowdown operations including compressor 

blowdown and emergency shut-down (ESD) system testing", all of which can 

be considered related to the process. Please confirm that venting due to 

actual emergency shutdowns [not due to ESD system testing] is not included 

in the blowdown vent stack source category.

At least 1 

individual

Helpline

Amend the definition of 

"supplier" in 98.6 to refer 

to those source categories 

listed in Table A-5 to 

subpart A of part 98.

The applicability of 40 CFR 98 is unclear. It appears as though a facility in 

the chemical industry, for example, might import to and export from their 

U.S. facilities products not included in the definition of supplier. The 

products are not intended for combustion. 

For example, a facility could produce plastic resins that are classified under 

NAIC code 325211. It may import materials that could be classified in the 

“Miscellaneous Products” category of the “Petrochemicals Feedstocks” 

grouping in Table MM-1. However, the sole purpose of importing these 

materials to their facility is to use them as raw materials in the production of 

plastic polymers. In the course of producing plastic polymers, a by-product 

may be created that can be used as raw material for manufacturing a product 

outside the U.S.

It appears that the definition of supplier is key for this facility. The definition 

of supplier in §98.6 is “Supplier means a producer, importer, or exporter of a 

fossil fuel or an industrial greenhouse gas.” Materials these members import 

are intended for use as raw materials in production and materials that they 

export are intended for use as raw materials in other petrochemical based 

processes, not for combustion, and therefore these materials do not meet the 

definition of “Fossil Fuels”, which is: “Fossil fuel means natural gas, 

petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from 

such material, including for example, consumer products that are derived 

from such materials and are combusted.” Emphasis added. Thus, we believe 

At least 2

individuals

Helpline
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Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

that such a facility does not meet the definition of supplier.

Subpart A at §98.2(a) establishes who must report; “The GHG reporting 

requirements...apply to...any supplier that meets the requirements of 

paragraph (a)(4).” Because this facility is not a supplier, as defined in the rule, 

we believe that it does not have to evaluate the requirements of paragraph 

(a)(4). It is the provisions of that paragraph §98.2(a)(4) that bring you to 

Subpart MM. Thus, Subpart MM does not apply.

Amend the definition of 

"supplier" in 98.6 to refer 

to those source categories 

listed in Table A-5 to 

subpart A of part 98.

The GHG Reporting Rule applies to facility owners and operators, and

suppliers. 40 CFR 98.2. The term "supplier" is defined at 40 CFR 98.6 as,

among other things, an importer or exporter of "fossil fuel." EPA

discussed the definitions of supplier and fossil fuel in an August 11,

2010 rule amendment proposal, and proposed to amend the definition of

fossil fuel in Section 98.6 to clarify that it applies to substances

derived from natural gas, petroleum or coal "for the purpose of creating

useful heat." EPA adopted this change in a final rule amendment, an

advance publication copy of which EPA has posted to its website.

EPA’s discussion in the proposed rule amendment indicated that the change

to the fossil fuel definition would ensure that fossil fuel is defined

clearly to refer to materials produced for the purpose of creating useful

heat. 75 Fed. Reg. 48744, 48754 (August 11, 2010). When EPA issued the

final rule change, it also indicated in the preamble that it did not

intend to have any impact on the coverage of greenhouse gases under the

GHG reporting program. Prepublication Copy, p. 69.

Given that (i) EPA has stated that the term “fossil fuel” is intended to

be construed as natural gas, petroleum, coal, or substances derived from

these products, for the purpose of creating useful heat, (ii) 40 CFR 98.2

At least 2

individuals

Helpline
10

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

states that Part 98 is applicable to owners and operators of certain

facilities and to suppliers, (iii) the term “supplier” is defined as a

producer, importer, or exporter of a fossil fuel or an industrial

greenhouse gas, and (iv) EPA seems to indicate that its definitional

change is not intended to alter the original meaning of the rule, is it

accurate to conclude that the reporting rule sections applicable to

suppliers are intended to apply only to those who produce, import or

export natural gas, petroleum, coal, or substances derived from these

products, for the purpose of creating useful heat? Stated another way,

would a company that imports or exports chemicals for use in a

manufacturing process (e.g., to manufacture another chemical) and not for

use as a heat or energy source not be considered to be a “supplier” and

therefore not be subject to Subpart MM?

Amend 40 CFR 98.2(d) 

and (e) to clarify that that 

the applicability 

determination for 

importers should be 

assessed separately from 

the applicability 

determination for 

exporters

I have two questions regarding import/export that I am sure have been 

answered many times. I have multiple manufacturing facilities under the same 

corporate owner. Each facility may import or export HFC containing 

equipment and closed cell foam....

3. If only the exporting threshold is exceeded are we still required to report 

imports or do you only report for the activity for which the threshold is 

exceeded?

At least 4

individuals

Helpline

In the reporting applicability thresholds in 40 CFR 98.2(a)(4)(ii) for Subpart 

MM, are the reporting categories for refineries, importers greater than 25,000 

tonnes CO2e/yr, and exporters greater than 25,000 tonnes CO2e/yr 

independent of each other?

Helpline

If only the exporting threshold is exceeded are we still required to report 

imports or do you only report for the activity for which the threshold is 

exceeded?

Helpline

If a facility triggers the 25,000 threshold for exports, do they also need to 

report imports even though imports have not exceeded the 25,000 threshold?

Helpline
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Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

Clarifying Table A-5 to 

state that coverage and 

the applicability 

determination for 

importers and exporters 

under subpart MM 

includes suppliers of 

natural gas liquids.

Also related to amending

the definition of 

"supplier" in 98.6 to refer 

to those source categories 

listed in Table A-5 to 

subpart A of part 98.

Does 40 CFR 98, Subpart MM, apply to petroleum products being 

imported/exported to/from chemical plants? ExxonMobil has several chemical

plants that import/export Petrochemical Feedstocks and/or Natural Gas 

Liquids (as listed in Table MM-1) to support our chemical manufacturing 

processes. However, chemical plants do not meet the definition of "Supplier", 

as found in §98.6:

Supplier means a producer, importer, or exporter of a fossil fuel or an 

industrial greenhouse gas. Fossil fuel means natural gas, petroleum, coal, or 

any form of solid,liquid, or gaseous fuel derived from such material, including 

for example, consumer products that are derived from such materials and are 

combusted. Industrial greenhouse gases means nitrous oxide or any 

fluorinated greenhouse gas.

The petrochemical feedstocks and/or natural gas liquids being 

imported/exported by ExxonMobil chemical plants are not "Fossil fuels" (as 

defined above) because they are not used for combustion, nor are they 

Industrial greenhouse gases. Therefore, it appears that chemical plants do not 

meet the definition of Supplier and, consequently, Subpart MM should not 

apply to these entities. Please clarify EPA's intent regarding applicability of 

Subpart MM to chemical plants.

At least 1 

individual

Helpline

Amend the definition of 

"United States parent 

company(s)" in 40 CFR 

98.6 to replace the term 

“reporting entity” with 

the term “facility or 

supplier.”

Section 98.3(c)(11) requires reporting of information on the U.S. parent 

company of the "reporting entity." Part 98 does not define "reporting entity." 

Section § 98.3 states that the reporting requirements apply to the "owners and 

operators of any facility" that meets the applicability provisions of that 

section. Similarly, Subparts C and D state that "you" must report and § 98.2 

defines "you" as "an owner or operator" subject to Part 98. However, in the 

proposed and final rules on parent company reporting, EPA describes the rule 

as requiring reporting by "facilities" and "suppliers" and refers to the 

"reporting entity" as the "facility or supplier," and not as the "owner and 

At least 1 

individual

Helpline
12

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

operator" of the facility or supplier. See, e.g., 75 Fed. Reg. at 18457; 75 Fed. 

Reg. at 57676. As a result, it appears that EPA intends the reporting of parent 

company information under § 98.3(c)(11) to be limited to the owner of the 

facility. Please confirm that the rule does not require, and the reporting format 

(which has not been released) will not require, reporting of parent company 

information on the "operator" of a facility where the operator is not also the 

owner. If EPA intends reporting of parent company information on both, 

please explain where that is reflected in the proposed and final parent 

company rule and how EPA will ensure that reporting will not result in 

double-counting of reported GHGs at the parent company level.

Clarify threshold for 

electrical transmission 

and distribution 

equipment use in Table 

A-3.

Our site contains electrical transmission and distribution equipment that 

distributes power throughout the site. Within in this equipment are 

several sealed circuit breakers, containing a total of 1,740 pounds of 

SF6.

Originally we had determined that we did not meet the definition of a 

"facility" in relation to an electrical power system defined in §98.308. 

Recently it came to our attention that we do meet the definition of a 

"facility" and as a result meet the definition of the "electrical 

transmission and distribution use" source category (subpart DD). Since 

the "electrical transmission and distribution use" source category is a 

source listed on table A-3 of 40 CFR 98, subpart A, our site would 

automatically be subject to reporting emissions from 2011.

Since our electrical transmission and distribution equipment contains 

only "sealed" circuit breakers, containing a total of 1,740 pounds of 

SF6, the site would be under the 17,820 pound threshold for having to 

report emissions from the "electrical transmission and distribution" 

At least 2 

individuals

Helpline
13

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

source category. While the site would not have to report emissions 

from this source category we would still be subject to reporting due to 

having a source listed on the "all-in" table (table A-3). The only source 

category that would be reported then would be the "General Stationary

Combustion Sources" source category with emissions of approximately

9k metric tons (MT) CO2e.

With emissions of approximately 9k MT of CO2e, we feel that we are 

not the "big-hitter" facility that was intended to be subject to this 

reporting requirement. We believe that the "electrical transmission and 

distribution use" source category as listed on table A-3 should include 

the 17,820 pound threshold just as the "municipal solid waste landfills" 

source category, as listed on table A-3, is only an "all-in" source if the 

emissions are 25k MT CO2e.

I have a question about how EPA interprets the phrase in 98.2(a) that 

states: "the annual GHG report must cover stationary fuel combustion 

sources (subpart C of this part), miscellaneous use of carbonates (subpart 

U of this part), and all applicable source categories listed in Table A3 and 

Table A4 of this subpart." I assume that this phrase means that I must 

evaluate each category to see if I qualify and, if so, must report for that 

category. However, the language raises the following questions:

1) does the specific mention of "carbonates" mean that I must report 

CO2e from carbonates even if I don't qualify for subpart U?

2) the calculation methodology in 98.2(b) states I must consider 

fluorinated gases. If I am in a category that does not consider these gases, 

do I need to consider them as a result of 98.2? For example, if I am a 

general industrial source, but have a transformer that could leak 

SF6, must I include SF6 emissions even though I don't meet the 

Helpline
14

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

requirements of an electrical distribution system?

Subpart W – Petroleum and Natural Gas

Definition of gas well In the published version of Subpart W, you define gas wells in 98.238 as 

follows: "Gas well means a well completed for production of natural gas from 

one or more gas zones or reservoirs. Such wells contain no completions for 

the production of crude oil." This definition appears to exclude any gasproducing well that also was completed to produce any amount of crude oil. 

We assume, therefore, that any well that produces crude oil, no matter 

whether it produces gas to sales, is excluded from reporting under the 

following source categories in Subpart W: (5) Gas well venting during well 

completions without hydraulic fracturing. (6) Gas well venting during well 

completions with hydraulic fracturing. (7) Gas well venting during well 

workovers without hydraulic fracturing. (8) Gas well venting during well 

workovers with hydraulic fracturing. Please confirm that our interpretation is 

correct. We assume that gas wells that also produce hydrocarbon condensate 

are INCLUDED in these categories (since condensate is not crude oil). But oil 

wells that produce gas are excluded.

At least 4

individuals

Helpline

For 98.232(c), Onshore Production, source categories (5)-(8): Do these 4 

source categories ONLY pertain to natural gas wells, OR to both oil and gas 

wells? If they only pertain to gas wells, please explain the definition of a 

"Gas Well." In section 98.238, the Rule defines a "Gas Well" as "a well 

completed for production of natural gas from one or more gas zones or 

reservoirs. Such wells contain no completions for the production of crude oil." 

Helpline
15

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

This definition is unclear - does this mean the gas well has to produce dry gas 

only? What if it produces condensate or light oils with the gas - can this be 

differentiated from crude oil in the Rule's definition?

Sections 98.233(g) and 98.233(h) require that "gas well" venting during 

completions and workovers from hydraulic fraction and "gas well" venting 

during completions and workovers without hydraulic fraction, respectively, be 

estimated. Section 98.238 provides the following definition for "gas well": 

means a well completed for production of natural gas from one or more gas 

zones or reservoirs. Such wells contain no completions for the production of 

crude oil. This definition appears to exclude "oil wells" from reporting under 

Sections 98.238(g) and (h). Can EPA confirm then, that crude oil producing 

wells are not required to report venting emissions associated with well 

completions and workovers (with or without hydraulic fracturing) and that 

EPA's intent was to only have wells meeting the provided definition of "gas 

well" report these vented emissions?

Helpline

For 40 CFR 98 Subpart W, is there any guidance on how to classify a well as 

a "gas well" and as an "oil well" other than the definitions in 40 CFR 98.237? 

Can we use the gas-to-oil ratio (GOR) of the well to classify the well as a "gas 

well" or as an "oil well"? Some operators and petroleum engineers use the 

following criteria for oil versus gas wells: For wells with a GOR of <10,000 

standard cubic feet per barrel, the well is classified as an oil well. For wells 

with a GOR of >10,000 standard cubic feet per barrel, the well is classified as 

an gas well.

Helpline

Clarifying the 25 MMscf 

throughput threshold for 

the onshore natural gas 

processing industry 

segment to state that the 

throughput threshold is 

based on an annual 

As I interpret the recently finalized Subpart W, gas processing facilities that 

do not process more than 25 mmScf/day are not subject to reporting under 

Subpart W regardless of whether they are subject to reporting under Subpart 

C. Can you please provide more guidance on how this threshold should be 

calculated? Is it an average daily throughput based on the entire reporting 

year?

At least 5

individuals

Helpline
16

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

average throughput.

Section 98.230(a)(3)(ii) states that "All processing facilities that do not 

fractionate with throughput of 25 MMscfd per day or greater." are included in 

the source category. Please specify the basis for the 25 MMscf per day 

throughput - is this based on annual average daily flow or max design 

capacity?

Helpline

25 mmscf/day is design capacity for a processing plant or the actual in the 

following definition in 98.230(a)(3):

Onshore natural gas processing. Natural gas processing separates and recovers 

natural gas liquids (NGLs) and/ or other non-methane gases and liquids from 

a stream of produced natural gas using equipment performing one or more of 

the following processes: oil and condensate removal, water removal, 

separation of natural gas liquids, sulfur and carbon dioxide removal, 

fractionation of NGLs, or other processes, and also the capture of CO2

separated from natural gas streams. This segment also includes all residue gas 

compression equipment owned or operated by the natural gas processing 

facility, whether inside or outside the processing facility fence. This source 

category does not include reporting of emissions from gathering lines and 

boosting stations. This source category includes:

(i) All processing facilities that fractionate.

(ii) All processing facilities that do not fractionate with throughput of 25 

MMscf per day or greater

Per this definition, we understand that if a booster processes 25 or more 

mmscf/day gas and generates condensate or produced water, it is considered 

Natural gas processing per this quoted definition. Please verify. 

Helpline
17

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

98.230(3) – Onshore natural gas processing. The regulation specifies that all 

processing facilities that do not fractionate but have a throughput of 

25MMSCF/day or greater is required to report. Our clients expect that this 

would be based on actual annual average since this is an annual report of 

actual emissions. Please confirm.

Helpline

Clarifying the throughput 

threshold for glycol 

dehydrators to state that 

the throughput threshold 

is based on an annual 

average throughput.

98.233(e) – Dehydrator vents. The regulation requires producers and 

processors to identify which dehydrators have a throughput less than 0.4 

MMscf/day. Our clients expect that this would be based on actual annual 

average since this is an annual report of actual emissions. Please confirm.

At least 2

individuals

Helpline

How should the daily throughput be determined for dehydrators in 98.233(e) 

to compare to the threshold of 0.4 MMscf/day? Is it based on design capacity, 

maximum daily throughput, or annual average actual daily throughput? Is the 

throughput re-evaluated annually?

Reporting requirements 

for blowdown vent stacks

Section 98.233(i)(3) states that one should "calculate the total annual

venting emissions for each equipment type using Equation W-14 of this 

section." The parameter Vv is defined as the total volume of blowdown 

equipment chambers (including pipelines, compressors and vessels) between 

isolation valves in cubic feet, therefore the equation calculates the emissions 

for all the equipment between isolation valves which could include different 

types of equipment. However, the reporting section 98.236(c)(7)(i) states that 

emissions should be reported by individual equipment type. How should a 

facility report the emissions if there is more than one type of equipment 

between isolation valves for Equation W-14?

At least 1

individual

Helpline
18

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

Clarifying the throughput 

threshold for onshore 

production storage tanks 

to state that the 

throughput threshold is 

based on an annual 

average throughput.

98.233(j) – Onshore production storage tanks. The regulation stipulates that 

calculation methodologies for onshore production storage tanks depends on 

whether the separator has a throughput greater than or equal to 10 barrels per 

day. Our clients expect that this would be based on actual annual average 

since this is an annual report of actual emissions. Please confirm.

At least 3

individuals

Helpline

The various methodologies for onshore production storage tanks in 98.233(j) 

are based on whether the daily oil throughput is greater than or less than 10 

barrels/day. How should the daily oil throughput be calculated? Is it the 

annual throughput divided by the number of days that the well produced 

during the year? Or the annual throughput divided by the number of days in 

the calendar year (i.e, 365 or 366)? Or some other method?

Helpline

How should the daily oil throughput be determined for onshore 

production storage tanks in 98.233(j) to compare to the threshold of 10 

barrels/day? Is it based on design capacity, maximum daily throughput, 

or annual average actual daily throughput? Is the throughput reevaluated annually?

Clarify that N2O , CH4, 

and CO2 must be 

reported under the natural 

gas processing industry 

segment in 98.232(d) .

I wanted to confirm that for flares at onshore natural gas production facilities, 

CO2, CH4 and N2O should be reported; while at onshore natural gas 

processing facilities, only CO2 and CH4 should be reported. Is this correct?

At least 1 

individual

Helpline
19

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

Clarify the definition of 

GHGi in Equation W-1

For pneumatic devices, how and at what frequency should GHGi in Equation 

W-1 be determined for onshore petroleum and natural gas production 

facilities? Note that the equation does not refer to 98.233(u), so it is not clear 

how GHGi should be determined and at what frequency.

For pneumatic devices at facilities specified in 98.230(a)(3) through (a)(8),

Equation W-1 says GHGi equals 1, but it is not clear which species you are 

referring to. Do you mean GHGi equals 1 mole fraction of CH4? Do you 

mean GHG equals 1 mole fraction of CO2? Am I supposed to 

assume it equals 1 mole fraction of CH4 and CO2? Please clarify exactly 

which GHG species you are referring to in Equation W-1.

At least 5

individuals

Helpline

Equation W-1, legend entry for GHGi includes reference to facilities listed in 

98.230(a)(3) through (a)(8). However, reporting for this source (pneumatic 

device venting) is required only for onshore production (which is specifically 

mentioned earlier in this legend item), and NG transmission compression and 

underground NG storage, which are 98.230(a)(4) and (a)(5) respectively. I 

recommend changing this reference in the legend to reference only (a)(4) and 

(a)(5), to avoid confusion.

Regarding Equation W-1:

In legend,

GHGi = For onshore petroleum and natural gas production facilities, 

concentration of GHG i, CH4 or CO2, in produced natural gas; for facilities 

listed in §98.230(a)(3) through(a)(8), GHGi equals 1. Why include 

98.230(a)(3) through (a)(8), given that, of these segments, reporting of 

emissions from pneumatic device venting is required only for NG 

transmission compression [98.230(a)(4)] and underground NG storage 

[98.230(a)(5)], in addition to onshore production facilities which are specified 

in first phrase.
20

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

For pneumatic devices, how and at what frequency should GHGi in Equation 

W-1 be determined? Similarly for Equation W-31. Note, these equations do 

not refer to 98.233(u).

Helpline

In 98.233(a), Eq W-1 has the parameter: "GHGi = For onshore petroleum and 

natural gas production facilities, concentration of GHG i, CH4 or CO2, in 

produced natural gas; for facilities listed in §98.230(a)(3) through (a)(8), 

GHGi equals 1." However, for facilities listed in 98.230(a)(3) through (a)(8), it 

is not realistic or reasonable for GHGito equal 1 for both CH4 and CO2. Did 

EPA intend to provide a GHGi for both CH4 and CO2? For example, in 

98.233(q), Eq W-30 has: "GHGi = For onshore natural gas processing 

facilities, concentration of GHGi, CH4 or CO2, in the total hydrocarbon of the 

feed natural gas; for other facilities listed in 98.230(a)(4) through (a)(8), 

GHGi equals 1 for CH4 and 1.1 × 10-2 for CO2." OR, did EPA intend that 

only CH4 emissions should be calculated for natural gas pneumatic device 

venting for facilities listed in 98.230(a)(3) through (a)(8)?

Helpline

Clarify the definition of 

GHGi in Equation W-2 to 

include a reference to 

paragraph 98.233(u)(2)(i)

For natural gas driven pneumatic pumps, how and at what frequency should 

GHGi in Equation W-2 be determined for onshore petroleum and natural gas 

production facilities? Note that the equation does not refer to 98.233(u), so it 

is not clear how GHGi should be determined and at what frequency.

At least 1 

individual

Helpline

Amend 98.233(d) to 

clarify calculation 

methods for acid gas 

removal vents.

Assume that a facility which receives and fractionates a natural gas liquids 

stream is subject to Subpart W, and the facility has an acid gas removal unit 

but cannot comply with Methodology #1 or #2 for acid gas removal units. 

This facility does not have a continuous gas analyzer on the gas stream out of 

the AGR unit and does not take quarterly samples of the gas stream out of the 

AGR unit. Therefore, the facility would prefer to use 98.233(d)(8)(iii) to 

determine the volume fraction of CO2 content in the gas stream out of the 

AGR unit. However, what would be the sales line quality specification for 

CO2 in "natural gas" for this facility, as the facility does not process or sell a 

At least 1 

individual

Helpline
21

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

natural gas stream? Would this be the CO2 specification for the outlet gas 

stream for the AGR unit?

Clarification of 98.233(e) 

for the calculation of 

emissions from 

dehydrator vents.

Subpart W 98.233(e)(1)(xi)(A) (related to dehydrator wet natural gas 

sampling) reads, "Use the wet natural gas composition as defined in paragraph 

(u)(2)(i) of this section." Is it correct that this is meant to only reference 

(u)(2)(i) which is only applicable to Onshore Petroleum and natural Gas

Production Facilities? Or, is it supposed to reference all of (u)(2), which 

would include other source categories as well ?

At least 1 

individual

Helpline

Amend 98.233(e)(1) to 

clarify that 0.4 mscf/day 

throughput threshold is 

determined using annual 

average daily throughput.

For emissions under §98.233(e)(1), emissions must be calculated from 

dehydrator vents with throughput greater than or equal to 0.4 million standard 

cubic feet per day. Is this throughput specific to vent throughput or dehydrator 

throughput?

At least 2 

individuals

Helpline

The selection of the two methodologies for dehydrator vents in 98.233(e) is 

based on whether the daily throughput is greater than or less than 0.4 

MMscf/day. How should the daily throughput be calculated? Is it the annual 

throughput divided by the number of days that the dehydrator operated? Or 

the annual throughput divided by the number of days in the calendar year (i.e, 

365 or 366)? Or some other method?

Helpline

Amend 98.233(f) and 

Equation W-8 to state 

that calculation 

methodology 2 is to be 

used to calculate the total 

emissions for well 

There appear to be several issues with equations W-8 and W-9.

The equations include a pressure correction, but not a temperature 

correction The emission term that results from the equations is labeled as 

actual cubic feet, but the conversions really result in standard cubic feet due to 

the pressure correction The equations then reference equation W-33 which 

At least 1 

individual

Helpline
22

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

venting for liquids 

unloading.

Amend Equation W-9 

converts from actual to standard conditions, essentially double correcting for 

pressure. The units in the second part of the equations are not clear. If HR is 

an annual value (sales flow rate/hr per year), than subtracting 1 hour or 30 

minutes from annual hours is meaningless. If HR is on an event basis or daily 

basis, then the equations are missing a summation.

Amend Equation W-13 to 

correct parameter 

definitions.

Equation W-10 is mentioned under Completions and Workovers with 

hydraulic fracturing, but the equation itself only mentions completions. 

Equation W-13, under completions and workovers without fracturing, some 

equation terms reference walkovers and others reference completions. Please 

clarify the terms associated with these equations in their use for both 

workovers and completions.

At least 1 

individual

Helpline

The emission factor applied in Equation W-13 is already on a CH4 basis, but 

the rule treats the output from Equation W-13 as if it is on a total gas basis. 

Equation W-13 is also expressed at actual conditions, but the emission factor 

applied is based on standard conditions of 60 °F and 14.7 psia.

At least 1 

individual

Helpline

Clarify that the parameter 

“Vv” in Equation W-14 

is the actual physical 

volume of the blowdown 

equipment.

The calculation methodology for blowdown vent stacks indicates that natural 

gas volumetric emissions at standard conditions (calculated using Eq. W-14) 

are to be converted to GHG mass emissions using the methodology in 

98.233(v). Unless the blowdown stream was a pure CH4 or CO2 stream, 

natural gas volumetric emissions cannot be converted directly to GHG mass 

emissions. Before volumetric natural gas emissions can be converted to GHG 

mass emissions, the volumetric natural gas emissions must first be converted 

to GHG volumetric emissions. Please confirm that emissions for 

blowdown vent stacks should be calculated using the following approach: 

volumetric natural gas emissions at standard conditions [98.233(i), Eq. W-14], 

convert to GHG volumetric emissions (CH4 and CO2) at standard conditions 

[98.233(u), Eq. W-35], convert to GHG mass emissions at 

standard conditions [98.233(v), Eq. W-36].

At least 2 

individuals

Helpline

The preamble to Subpart W discusses that total physical volumes of 50 cubic 

feet or less are exempt from reporting. However, the regulation states that 
23

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

total volume of 50 standard cubic feet or less are exempt from reporting. 

Standard cubic feet may differ greatly from physical cubic feet.

Amendments to 

parameter “En” and 

removal of parameter 

“Et” of Equation W-16 

I am not understanding Equation W-16 (98.233(j)(8)) that is to be used when 

a dump valve on a separator fails to close. The confusion involves En and Et. 

The first part of the equation is to calculate emissions when the dump valve is 

stuck open and includes a correction factor (5.37 for gas condensate 

production) that is multiplied by En and the hours the valve was stuck open. 

En is supposed to tank emissions during Tn, which is when the valve is stuck 

open. Methodologies 1,2, or 5 does not give you the emissions when the valve 

is stuck open - it gives an emission estimate off the oil tank under normal 

operations. What is the correction factor for if En is supposed to be the 

emission rate during the malfunctioning valve? It would make more sense to 

me if En and Et were the same - whatever is calculated in Methodologies 1 - 5 

converted to a scf per hour. Then the correction factor would be used to 

increase the emissions (by 5.37 times) during the hours that the valve was 

malfunctioning. Unless En and Et are the same, I don't see how the EPA's 

equation will work. ow do you determine En? How is it different from Et? 

How do you determine Et?

At least 1 

individual

Helpline

Clarify 98.233(k)(4)(ii) 

to state that the flare 

stack calculations are to 

be used for emissions 

that are sent to a flare and 

not from a flare.

Under §98.232(e), emissions from flares are not a required source for 

calculation and reporting. Under section §98.233(o)(9), however, emissions 

from flares associated with centrifugal compressors must be reported. There 

are multiple cases throughout Subpart W where these confusions exist (i.e. 

section §98.233(k)(4), which is specific to the transmission compression 

industry segment). Please clarify which section of the rule is the correct 

guiding action.

At least 1 

individual

Helpline

Clarifying the density 

parameter in Equation 

W-36

Section 98.233(v) GHG mass emissions Eq. W 36 in Subpart W, uses a 

density of 0.0538 kg/ft3for CO2 and 0.0196 kg/ft3for CH4 at 68°F. It uses 

0.0530 kg/ft3for CO2 and 0.0193 kg/ft3for CH4 at 60°F. Are these values 

correct, I would expect the gas to be denser at a lower temperature?

At least 1

individual

Helpline
24

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

Amend 98.233(z) for 

determining combustion 

emissions from both the 

onshore petroleum and 

natural gas production 

and natural gas 

distribution industry 

segments.

98.233(z) directs onshore petroleum and natural gas production and natural 

gas distribution to calculate CO2, CH4, and N2O emissions from combustion 

sources. Calculation approaches are clearly defined for CO2 and N2O, but are 

not clearly defined for CH4. 98.233(z)(1) indicates that if the fuel combusted 

is listed in Table C-1 (or is a blend of fuels in Table C-1) then the Tier 1 

calculation methodology in Subpart C must be used. Please confirm that the 

use of the Tier 1 approach applies to the calculation of both CO2 and CH4

emissions. Please also indicate how CH4 emissions are to be calculated for 

sources that combust field or process vent gas.

At least 3

individuals

Helpline

98.233(z) says to use Eq. W-39 to calculate "GHG emissions". But doesn't 

that equation yield only CO2 emissions? How are CH4 emissions to be 

calculated? Also, the explanation of the HHV parameter in Eq. W-40 (for 

calculating N2O emissions) refers to "paragraphs (z)(8)(i), (z)(8)(ii), 

or(z)(8)(iii)". I believe the references should be to (z)(6) instead of

(z)(8) as there is no (z)(8).

Helpline

Reporters are required to estimate CO2, CH4, and N2O emissions from 

combustion sources under paragraph (z) of Subpart W. If a reporter combusts 

a common fuel, emissions of CO2 and CH4 are estimated using Tier 1 in 

Subpart C while N2O emissions are estimated using equation W-40. If a 

reporter combusts a solid or liquid fuel not listed in Table C-1, emissions 

should be estimated using Tier 2 of Subpart C. Reporters that combust field 

gas or process vent gas (neither listed in Table C-1) estimate emissions of 

CO2 using equation W-39 and emission of N2O using equation W-40. How 

should CH4 emissions be estimated? Equation W-39 assumes all CH4 is 

converted to CO2 during combustion.

Helpline

Revised Equation W-40 

to account for an 

incorrect exponent.

Equation W-40: In the equation, the conversion factor from kg to metric tons 

is given as 1 x 103; the conversion factor should be 1 x 10-3, as given in the 

legend.

At least 3

individuals

Helpline

Equation W-40 has a factor (1 x 103) that should be 1 x 10-3). Helpline

Regarding Equation W-40: Helpline
25

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

Equation is given as: N2O = (1 x 103) x Fuel x HHV x EF (Eq. W-40)

Legend includes:

EF = Use 1.0 × 10-4kg N2O/mmBtu.

1 × 10-3= Conversion factor from kilograms to metric tons.

HHV = High heat value of the fuel from paragraphs (z)(8)(i), (z)(8)(ii) or 

(z)(8)(iii) of this section (units must be consistent with Fuel).

Q: Shouldn't the factor in the equation include the -3 exponent instead of +3, 

for correct conversion from kg to metric tons?

Q: Paragraphs referenced by HHV legend do not exist; reference should 

probably be to (z)(6) rather than (z)(8).

Insert missing variables 

in Equation W-41.

Equation W-41: The legend is missing the terms "a" and "b". At least 2

individuals

Helpline

Regarding Equation W-41: Legend is missing terms "a" and "b". Helpline

Revise emission factors 

for high bleed, low bleed, 

and intermittent bleed 

pneumatic devices on a 

total hydrocarbon basis.

The derivation provided in the TSD for the high bleed, low bleed, and 

intermittent bleed pneumatic device emission factors provided in Table W-1a 

introduces an error. The derivation incorrectly divides by the CH4 weight 

fraction (e.g. D=0.788). 

At least 1

individual

Helpline

Subpart FF – Underground Coal Mines
26

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

Amending Table A-3 to 

revise applicability to 

mines liberating 

36,500,000 acf of CH4 or 

more per year from their 

ventilation systems

My question concerns interpretation of the applicability of reporting for 

underground coal mines under Subpart FF. The July 12, 2010 rule states 

active mines that are monitored quarterly by MSHA must report, whereas all 

other facilities have a 25,000 metric ton threshold. The May 26, 2010 (revised 

June 29, 2010) Technical Support Document for Underground Coal Mining 

states that only 19% of mines will need to report with emissions estimated to 

be about 15,000 metric tons CO2e or more. Are all active mines that have 

MSHA quarterly monitoring (or more frequent) required to report or only 

those with emissions of 15,000 metric tons or more?

At least 2

individuals

Helpline

In 40 CFR part 98, subpart FF the term(s)"MSHA threshold" appears but it is 

not elsewhere defined. Could you please cite a reference or provide me with a 

definition of that term.

Helpline

Placement and timing of 

sampling for moisture 

content

If we are taking dry samples, how are we supposed to get moisture content 

readings from dry samples? Is there a sampling method or certain type of 

equipment that we use to get these readings/values? The rule states that 

moisture content readings should be taken quarterly for vent systems and 

weekly for degas systems.

At least 2

individuals

Helpline

What apparatuses have been approved to record methane, moisture content, 

air flow, barometric pressure, and temperature to satisfy 40 CFR Part 98?

Helpline

Clarification of how to 

measure for moisture 

content and amendment 

of Equations FF-1 and 

FF-3

One of the requirements for the testing of both ventilation air and degas 

system samples is moisture content in %. Is this the atmospheric moisture 

content or the moisture content of the gas sample?

At least 3

individuals

Helpline

If we are taking dry samples, how are we supposed to get moisture content 

readings from dry samples? Is there a sampling method or certain type of 

equipment that we use to get these readings/values? The rule states that 

moisture content readings should be taken quarterly for vent systems and 

weekly for degas systems.

Helpline

Can you please share the appropriate methodology and equipment for 

collecting quarterly grab samples for methane, flow, temperature, and 

Helpline
27

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

pressure in ventilation shafts of underground mines?

Use of MSHA data to 

calculate emissions

Two mines have monitored for methane to satisfy quarterly MSHA 

requirements. MSHA lab analyses of bag samples have consistently shown 

zero methane concentration (0.000 %) in the mine ventilation air. I believe air 

flow rates at the ventilation air intake and exhaust points are currently 

estimated from fan performance curves. My question: do these mines need to 

invest in more precise air flow measurement technology as long as they 

continue to show zero methane, or can they simply use the data from their 

MSHA reports to complete the GHG emissions report?

At least 3

individuals

Helpline

Can you please share the appropriate methodology and equipment for 

collecting quarterly grab samples for methane, flow, temperature, and 

pressure in ventilation shafts of underground mines? I have looked at the 

reference section of the regulations but it is not clear to me which methods are 

the appropriate methods to use. It is my understanding that MSHA does not 

monitor pressure and their instrumentation does not correct for pressure.

Helpline

Under Subpart FF, underground coal mines must report emissions from 

ventilation systems. Section 98.324(b)(2) indicates that the data could be 

obtained from "the quarterly (or more frequent) testing performed by MSHA." 

The concern is that MSHA has never reported temperature and pressure data 

in the past, and these are required to calculate emissions in equation FF-1. 

Have arrangements been made for MSHA to collect this REQUIRED data? If 

not, what default values can the mines use? Or, if not, will the mines be 

required to supplement the MSHA reported data by taking their own 

temperature and pressure readings in each quarter and at all of the same 

locations where MSHA samples?

Helpline

Clarification of 

monitoring equipment 

required

What apparatuses have been approved to record methane, moisture content, 

air flow, barometric pressure, and temperature to satisfy 40 CFR Part 98?

At least 2

individuals

Helpline

Can you please share the appropriate methodology and equipment for 

collecting quarterly grab samples for methane, flow, temperature, and 

pressure in ventilation shafts of underground mines? I have looked at the 

Helpline
28

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

reference section of the regulations but it is not clear to me which methods are 

the appropriate methods to use. It is my understanding that MSHA does not 

monitor pressure and their instrumentation does not correct for pressure.

Subpart II– Industrial Wastewater Treatment

Replace the term “landfill 

gas” with “biogas” in 

98.352(d)

In the final rule published on July 12, 2010, in paragraph 98.352(d) of Subpart 

II, Industrial Wastewater Treatment, reference is made to landfill gas 

destruction device. I believe this is an error since it has no relation to the 

Subpart.

At least 1 

individual

Helpline

Error in Equation II-6 We have identified an error in Equation II-6 of Subpart II (industrial 

wastewater treatment) for calculating methane emissions from a wastewater 

treatment operation where some of the generated methane is captured and 

destroyed. 

The equation will return erroneously high results for methane emissions in 

many scenarios. The correct form of the equation is:

CH4En = CH4Ln + Rn (1− [ (DE1 ∗ fDest_1 )+ (DE2 ∗ fDest_2)])

At least 2

individuals

Helpline

Eq. II-6 in Subpart II for industrial wastewater treatment appears to have an 

error. Since Rn is the total methane recovered and that value is the multiplier 

for each destruction device, it ends up double counting

emissions since the primary and back-up device emissions are added. 

Essentially the total methane Rn is first multiplied by the efficiency of the 

first device and then you take the entire methane value again and multiply it 

by the back-up device efficiency and then add the two values. The equation 

results in more methane being emitted than is recovered.

Subpart TT – Industrial Waste Landfills
29

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

Determining 

waste-specific 

DOC values for 

closed landfills

The preamble for Industrial waste landfills indicates EPA's desire to not require 

reporting for landfills that only received inert or inorganic waste. 98.460(c)(2) 

includes a list of specific wastes that are considered inert, along with other 

criteria in 98.460(c)(2)(xii) – volatile solids concentration of less than 0.5%. It 

seems that per 98.464 that in order to claim the waste is less than 0.5% volatile 

solids that sampling and testing are required. Our company has some landfills 

that only accepted inert wastes, such as waste from magnesium metal production, 

and magnesium hydrate. The facilities have since shutdown and the landfills are 

closed, so obtaining a sample cannot be done. These wastes contain no carbon. Is 

it possible to use process knowledge to determine that a material is inert or has a 

volatile solids content of less than 0.5%? Solid waste regulations allow for the 

use of process knowledge during waste characterization. If not, this will require 

extensive effort to over report emissions that we know do not exist. Since the 

material cannot be sampled, the values in Table TT-1 for "other industrial waste" 

would need to be used, resulting in a waste that does not contain carbon reporting 

the same emissions as waste from the pulp and paper industry.

At least 1 

individual

Helpline

Delete Equation 

TT-7 and amend 

Equation TT-8 for 

determining 

volatile solids and 

DOC values

The second error is in regard to the method presented for calculating a wastespecific DOCx value for waste streams using Equation TT-8 in Section 

98.364(b)(4). The key to Equation 8 states that the result of the calculation 

(DOCx) is "degradable organic content of waste stream in Year X (weight 

fraction, wet basis)." However, the equation as provided would return a DOCx 

value on a dry basis.

At least 1 

individual

Helpline

In 40 CFR 

98.463(a)(2), 

revise “January 1, 

1980” to be 

“January 1, 1960”

Based on the preamble text and the wording of § 98.463(a)(2), it would appear 

that EPA requires calculation and reporting of GHG only from waste

placed in landfills on or after January 1, 1980. However, definitions for terms in 

Equations TT-2 and TT-4 refer to calendar year 1960, not 1980, as

the earliest start date for landfill operation. Is the date 1960 that appears at 

Equations TT-1 and TT-4 a typographical error that should be 1980?

At least 11

individuals

Helpline
30

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

The text of Subpart TT indicates that the waste quantities to be used in the 

calculation of annual (methane) greenhouse gas are those that have been 

deposited in the landfill beginning on January 1, 1980. While the definition

for Start Year of equations TT-1 and TT-4 indicates that the owner or operator is 

to use 1960 as the start year. Which is correct?? 

Helpline

Are facilities required to calculate emissions beginning in 1960 or 1980? Eq. TT1 specifies that emission calculations are to begin in 1960 (or the opening year of 

the landfill if later), but 40 CFR 98.463(a)(2) specifies that annual waste 

quantities are to be determined beginning in 1980 (or the year the landfill first 

accepted waste).

Helpline

Clarify that only 

descriptions of 

waste streams 

disposed of in the 

landfill and used in 

Equation TT-1 

must be reported 

What is the reporting threshold for GHG emissions for Industrial Landfills under 

Subpart TT (since they do not fall under HH)"? What if they accept 60% ash at 

the landfills? Do we calculate only 40% of the emissions and report that 

number?

At least 1 

individual

Helpline

Definition of 

“construction and 

demolition waste 

landfill”

Under Subpart TT Industrial Waste Landfills, would a construction 

and demolition (C&D) landfill that accepts site clearance waste in addition to 

construction waste be exempt under 98.460(c)(1)? In the recent Oct 28, 2010 

amendment to subpart HH for Municipal Solid Waste Landfills, references to 

"dedicated C&D landfills" were removed and a new definition was added for 

"C&D waste landfill" that clearly references site clearance waste as a typical 

C&D waste. Did EPA intend for site clearance waste to be a typical waste 

received by dedicated C&D landfills under subpart TT?

At least 1 

individual

Helpline
31

Summary Of Questions And Issues From The EPA Helpline And Trade Associations Being Resolved By The Proposed Technical 

Corrections And Other Amendments

Technical Issue Question Submitted to EPA

Type and 

approximate 

number of 

submittals

Reference 

(Helpline or 

Trade 

Association 

materials)

Definition of 

“design capacity” 

in 98.468

What is the definition of "design capacity"? If the design capacity is greater than 

300,000 metric tons (MT), but the total facility is below 25,000 MT of CO2e per 

year (taking into account the inert material in the landfill), do they report?

At least 2 

individuals

Helpline

How is design capacity calculated when dealing with landfills that are not 

engineered landfills with a defined capacity? Is there some way to eliminate 

small landfills without going through an involved calculation process? The rule 

does not address this issue.

Helpline

Amend Table TT1 - revise the 

description of 

“Inert Waste”

In Table TT-1 of Subpart TT (Default DOC and Decay Rate Values for Industrial 

Waste Landfills), it refers to inert waste listed in section 98.460(b)(3). However, 

there is no (3) under 98.460(b). Should it read 98.460(c)(2)?

At least 2 

individuals

Helpline

In Table TT-1 it lists "Inert Waste [i.e., wastes listed in §98.460(b)(3)]." 

However, that reference is not in the rule, it only goes to §98.460(b)(2) then 

progresses to §98.460(c) which I suspect is the intended list but that is not what 

the table says. Then, when reviewing the list, the numbering goes from v to vii 

with no vi. I would think the correct reference would be to §98.460(c) - both (1) 

and (2).

Helpline