1



### Date: November 13, 2015

To: Cate Hight,

U.S. Environmental Protection Agency

From: Clark Talkington,

Vice President Advanced Resources International, Inc.

Subject: Use of inspection data from the Mine Safety Health Administration for

reporting quarterly methane liberation from mine ventilation shafts



## Summary

Since 2011, active underground coal mines liberating at least 36,500,000 actual cubic feet of methane (CH4) per year from mine ventilation shafts and/or degasification systems have been required to submit annual reports of their greenhouse gas (GHG) emissi ons to EPA’s Greenhouse Gas Reporting Program (GHGRP) under 40 Code of Federal Regulations (CFR) Part 98. Subpart FF of Part 98 outlines the annual greenhouse gas reporting requirements for Underground Coal Mines.

The GHGRP require s reporters to monit or methane emissions from mine ventilation shafts using
one of three options: (i) to take grab samples at the same location as the U.S. Mine Safety & Health Administration (MSHA) inspection samples are taken; (ii) to obtain results of quarterly testing p erformed by MSHA ; or (iii) Continuous Emissions Monitoring Systems (CEMS). Since reporting began in 2011, the number of reporters using grab samples and MSHA data have been roughly equal with slight variance from year to year

. In 2013, t he EPA tasked AR I to conduct a detailed review of the data and data sources for the GHGRP with a specific focus on MSHA quarterly reports for reporting methane liberation
from mine ventilation shaft s . The assessment included a review of MSHA sampling and reporting procedu res, several discussions with MSHA personnel and a review of MSHA data

.

We have concluded that MSHA reports can vary to a degree on a case by case basis that, while appropriate for mine safety regulation, makes them inappropriate for a more robust greenho use gas (GHG) emissions monitoring and reporting program.2

Our principal concerns with MSHA data are changes in the sampling locations from quarter to quarter at some mines, the difficulty in clearly identifying the specific shaft where the sampling

occu rred, and differences between data included in the MSHA reports and data presented by some GHGRP reporters using the MSHA data. These problems have made it very difficult to: (1) clearly define the number of shafts reporting to the GHGRP; (2) verify the quantity of methane liberated from each mine ventilation shaft at certain mines; and (3) develop more accurate estimates of total emissions from particular mines and of nationwide emissions for the underground coal sector.

We believe the appropriate sol ution is to remove use of MSHA data as an approved monitoring method for reporting methane liberated from ventilation systems. We understand that this would present an additional burden to approximately 50% of the reporting mines that now use the MSHA dat a, but believe that limiting the monitoring options to grab samples and CEMS will provide the EPA, the U.S.
Government and the public with more consistent and reliable data from which to formulate policy options for greenhouse gas reporting and management at coal mines.

While we encountered inconsistencies in some GHGRP reports using MSHA data, we emphasize
that the concerns over use of MSHA data are not concerns about the accuracy of the MSHA sampling
method s or sampling locations outlined in the MSHA C oal Mine Safety and Health General Inspection
Procedures Handbook 1 . On the contrary, we believe that the MSHA sampling methods achieve MSHA’s principal objective of assuring the health and safety of mine workers. These methods are sufficient for GHG rep orting where applied and reported consistently ; therefore, we recommend that the EPA continue to reference the MSHA Inspection Handbook as the appropriate guidance for taking grab samples under Subpart FF

.



## 2.0 Mine ventilation systems

All active und erground coal mines maintain high volume ventilation systems to bring fresh air into the mine and to dilute and disperse hazardous gases in underground mine entries

. The quantity of fresh air required is substantial. There are shafts in the United State s with total air throughput greater than 1 million cubic feet per minute. In general, MSHA mandates that maximum CH 4 concentrations in

a mine ventilation shaft not exceed 1 percent, except for high concentration “bleeder” shaft s (non

man/material shafts) which can operate at up to 2 percent CH 4 . Although methane concentrations are

1 MSHA (2013) Sampling locations should include all locations where air leaves the mine

. Coal Mine Safety and Health General Inspection Procedures Handbook: Handbook Number PH13

- V

- 1 . U.S. Department of Labor, Mine Safety and Health Administration. Office of Coal Mine Safety & Health. Washington, D.C.

, February 2013. http://www.msha.gov/Readroom/HANDBOOK/PH13

- V

- 1.pdf3

low in ventilation shafts, the sheer volume of air flow through the shafts result s in significant methane emissions. In the United States, ventilation shafts account for about two

- thirds of total methane emissions from underground mines or 36.9 million tons CO2e in 2014. 2



## 3 .0 Background

Since 2011, active underground coal mines liber ating at least 36,500,000 actual cubic feet of methane (CH4) per year from mine ventilation shafts and/or degasification systems have been required to submit annual reports of their greenhouse gas (GHG) emissions to EPA’s Greenhouse Gas Reporting Program ( GHGRP) under 40 Code of Federal Regulations (CFR) Part 98. The Greenhouse Gas Reporting
R ule was promulgated i n response to the FY2008 Consolidated Appropriations Act ( H.R. 2764; Public
Law 110

- 161) which requires reporting of greenhouse gas (GHG) data a nd other relevant information from large sources and suppliers in the United States. The purpose of the rule is to collect accurate and timely GHG data to inform future policy decisions.

Subpart FF of Part 98 outlines the annual greenhouse gas reportin g requirements for Underground Coal Mines. This sector comprises underground coal mines categorized by the Mine Safety and Health Administration (MSHA) as active (where coal is currently being produced or has been produced within the previous 90 days), an d underground mines under development that have operational pre

- mining degasification systems. Abandoned (closed) mines, surface coal mines, and
post

- coal mining activities are not included in the GHGRP

.
Proposed rules were published on April 10, 2009 3 in the Federal Register with Monitoring and QA/QC Requirements set forth in 40 CFR 98.324

. 4 The EPA proposed requiring reporters to monitor
methane emissions from mine ventilation shafts using one of two options: (i) to take grab samples at
the same location as the U.S. Mine Safety & Health Administrati o n ( MS HA) inspection samples are taken; or (ii) to obtain results of quarterly testing performed by MSHA

. In response to comments received on the proposed rule during the publi c comment period, the EPA included a third monitoring option in the f inal rule published on July 12, 2010 5

- Continuous Emissions Monitoring Systems (CEMS). Table 1 shows the breakdown of monitoring options chosen by Subpart FF reporters since reporting
b egan.

2 GHGRP 2014

3 Federal Register (FR). Vol 74, No. 68. Washington, D.C. April 10, 2009.

4 FR. Vol. 74. No. 68. Page 16698.

5 FR. Vol. 75, No. 132. Washington, D.C.. July 12, 2010. Pages 39736

- 39777 and 40 CFR Part 98.3244

Table 1: Ventilation monitoring option chosen by Subpart FF reporters

Year Number of

Reporting
Facilities 98.234(b)(1)

Grab Samples 98.234(b)(2)

MSHA Quarterly Reports 98.234(b)(3)

CEMS No Method

Reported

2011 114 40% 53% 0% 7%

2012 115 44% 48% 0% 8%

2013 126 48% 44 % 0% 7%

2014 128 45% 50 % 0% 5% *”N/A”

– Facilities did not report specific monitoring method

In addition to the GHGRP, the U.S. Environmental Protection Agency also produces the annual Inventory of U.S. Greenhouse Gas Emissions and Sinks (Inventory). 6 The Inventory includes annual
methane emissions for the U.S. coal sector, but its scope is much broader than the GHGRP as it includes methane emissions from surface mines, abandoned mines, and post

- mining operations (i.e., storage, processing and transportation of coal). In addition

, the Inventory includes emissions from underground coal mines that fall below the GHGRP reporting threshold. 7 In 2013, for example, the Inventory included
ventilation emissions from 205 mines whereas 126 mines reported to the GHGRP. 8

To produce the annual Inventory of coal mine methane emissions, EPA has historically relied o n annual summaries of quarterly MSHA data to develop estimates of methane emissions from ventilation systems. The data is presented in “ finished ” form rather than as raw data. Table 2 presents the level of detail in year

- end summaries provided by MSHA. The finished data is compiled from the more detailed
MSHA quarterly reports that include volumetric flow in cubic feet per hour and methane concentration on the date of sampling events. Figures 1

- 3 at the end of this memorandum present examples of the detail included in MSHA reports.

6 Environmental Protection Agency (EPA 2015). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990

- 2013. EPA 430

- R

- 15

- 004 . Washington, D.C. April 15, 2015. http://www3.epa.gov/climatechange/ghgemissions/usinventoryreport.html

7 In 2013, the U.S. Inventory included emissions from over 200 active underground mines compared to the GHGRP which included emissions from 126 active underground mines.

8 EPA 20155

Table 2 : Example of quarterly emissions data supplied by MSHA



## Sample Data fro m MSHA

MINE ID DISTRICT MINE NAME 1st QUARTER LIBERATION (mmcf/d) 2nd

QUARTER LIBERATION (mmcf/d) 3rd

QUARTER LIBERATION (mmcf/d) 4th

QUARTER LIBERATION (mmcf/d) AVERAGE

METHANE LIBERATION (mmcf/d)

000000 C02 Mine X 9,537,936 7,338,161 6,370,048 10,940,964 8,546,777

Reviewing the emission totals from the Inventory and the GHGRP for 2011 and 2012 revealed substantial differences between the two, even considering the differen ces in the data sets noted previously. This led the EPA to task subpart FF contractor ARI, supported by GHG Inventory contractor Ruby Canyon Engineering, to conduct a detailed review of the data and data sources for the Inventory
and the GHGRP in 2013 and 2014 with a specific focus on MSHA quarterly reports for reporting metha ne liberation from mine ventilation shaft s

. The assessment included a review of MSHA sampling and reporting procedures, several discussions with MSHA personnel and a review of MSHA reports from a
subset of mines where MSHA data and GHGRP data differed mo st significantly. S everal potential problems were identified with the use of MSHA data for GHG emission reporting based on this analysis.
This memo further elaborates on those concerns in Section 5 .0.



## 4 .0 MSHA ventilation s ampling p rocedures

MSHA conducts safety inspections at all underground mines on a quarterly basis . As part of the inspection, MSHA inspectors take air samples and air flow measurements in the roadways and shafts underground to ensure safe working conditions. The measuremen ts capture methane (CH 4 ) concentration and volumetric flow in approach es to exhaust shaft s , and , in some cases, measurements are taken at intake shafts. Inspectors take CH 4 concentration measurements following a published MSHA protocol (MSHA Coal Mine Saf ety and Health General Inspection Procedures Handbook:
Handbook Number PH13

- V

- 1) 9

. The Handbook specifies that samples be taken “ At all locations where air leaves the mine (to determine total mine methane liberation). On blowing ventilation systems thi s may include roadways, belt conveyor entries, and/or other areas where air leaves the mine .” 10 A ir samples are taken using vacuum sealed test tubes that are sent to MSHA laboratories for gas analysis.

9 MSHA (2013)

10 MSHA (2013)6

Air samples sent to the lab are routinely analyzed fo r five gases: CH 4 , carbon dioxide (CO 2 ), oxygen (O 2 ), ethane (C2H6), and nitrogen (N2). Inspector use 10

- milliliter (ml) air sample bottles or ‘vac

- u

- tainers®’
to collect the sample s

. Air flow m easurements are taken with hand

- held anemometers or pito t tubes

. For vertical exhaust shafts (a.k.a., upcast shafts ) , MSHA i nspectors take the measurements in approaches. Approaches are underground roadways leading to a n upcast exhaust shaft, and an exhaust
shaft may have multiple approaches

. Although the M SHA Inspection Handbook allows for taking air flow measurements in fan tubing and main fan ducts, experience in reviewing quarterly inspection reports indicates that methane samples are taken in the approaches. Inspectors are directed to collect samples during normal production times for accuracy.

M easurements taken during an inspection also provide MSHA with an assessment of total methane liberation (TL) at the mine in cubic feet per day. Generally, any mine liberating more than 100,000 cubic feet pe r day may be considered a mine wi th excessive methane liberation triggering additional inspection and oversight due to the greater potential for health and safety risk of fires, explosions, and air displacement.

After the bottle samples are taken, inspectors send the sample bottles and air flow

measurements to MSHA’s Gas Laboratory in Mount Hope , WV for analysis

. Results are provided to the regional office and inspectors, and m ine operators may be notified if there are potential safety

concerns

. The report w ill show e ach approach or intake shaft measured during the quarter, and for each approach or intake shaft :

o Date of measurement

o Bottle number for the CH 4 sample

o CH 4 concentration the air flow measu rement in cubic feet per minute

o Cubic feet of methane in a 24 hour period based on the CH 4 concentration and air flow

measurements.

MSHA may increase the frequency of inspect ions and sampling at its discretion. Based on consultations with MSHA, mining companies, and industry experts, we understand that inspections and sampling have occurred on a monthly and even weekly basis in some instances. However the default

measureme nt frequency is quarterly. *Note

- Total methane liberation calcu lated by MSHA is intended for safety purposes, not greenhouse gas emissions monitoring.7

The results are not provided to the mine operator automatically. Operators may be notified
when CH 4 concentrations reach levels of concern or when total methane liberated by the mine meets certain benchmarks. However, MSHA w ill provide the quarterly report should the operator request it.



## 5 .0 Potential problems with use of MSHA data for reporting
g reenhouse g as emissions monitoring

The stated purpose of the Act that created the GHGRP is to collect accurate and timely GHG data to inform future policy decisions. Through the 2014 reporting year, we have reviewed and verified 483 Subpart FF reports over four reporting years. Based on the analysis begun in 2013 and on four years of experience reviewing reported data, we hav e concluded that MSHA data as submitted by Subpart FF Reporters does not achieve the desired level of accuracy and consistency to effectively inform policy decisions by the EPA on monitoring and management of greenhouse gases

.

Our principal concern s wi th MSHA data are the change in the sampling locations from quarter to quarter at some mines, the difficulty in always clearly identifying the specific shaft where the sampling occurred, and differences between data included in the MSHA reports and that pre sented by some GHGRP reporters using the MSHA data. These are elaborated on in more detail below:

 Change in sampling locations by MSHA As noted previously, the objective of MSHA’s sampling program is to support its worker safety regulatory mandate. Ther efore, from quarter to quarter, the MSHA reports show that MSHA may change the shafts and approaches where samples are taken resulting in data gaps for the GHGRP reports. (see Figure 1)

 The names of approaches at a particular mine where measurements are taken may change in
MSHA reports from quarter to quarter

. MSHA inspectors , not the mine operator, name each approach where samples are taken for their inspection reports. Thus one or more a pproaches to a shaft at a mine may be named differently from quarter to quarter since a different inspector may conduct the inspection each
quarter

. However, there is no record to clarify the name change from report to report, so it
adds con fusion and uncertainty to the r evi ew of GHGRP reports

. (see Figure 1)

 Labeling of shafts in the GHGRP annual reports and the MSHA quarterly reports do not always match up.8

We found that at some mines, the m onitoring points in the GHGRP reports do not match up exactly with the MSHA qua rterly reports making verification of the GHGRP report more difficult

. (see Figure 2)

 Incorrect interpretation of MSHA data

o Total methane liberated in a ventilation shaft should be the sum of methane liberated in all approaches leading to that shaft in a particular quarter . Where reporters have aggregated data from multiple approaches to report CH 4 % and air flow for a single shaft,

we found that in some cases air flows have been averaged rather than summed

, significantly reducing the total air flow that should be used in equation FF

- 1 and thus
total methane liberated from the shaft

.

o The review also found cases where reporters aggregating data from multiple approaches for a single shaft, use a simple mathematical average of the CH 4 concentrations rather than the weighted average which is what should be used

. Depending on the air flow in each approach, this can have a neutral impact but can also incorrectly increase or decrease reported methane liberation rates providing inaccurate
data.

o In some instanc es, reporters have chosen a single approach to a shaft as representative of the methane liberated by that shaft, even though a shaft may have multiple approaches. This can significantly undercount methane emissions at that shaft. (see Figure 3)

These pr oblems make it very difficult to: (1) clearly define the number of shafts reporting to the GHGRP; (2) verify the quantity of methane liberated from each mine ventilation shaft at certain mines; and (3) develop more accurate estimates of total emissions fr om particular mines and of nationwide emissions for the underground coal sector.



## 6.0 Conclusions

For many years, the EPA has used MSHA quarterly ventilation data to estimate methane emissions from active underground coal mines for the U.S. Inventory . I n the development of the Greenhouse Gas Reporting Rule , the EPA believed that the MSHA reports could provide reliable data for emissions monitoring while reducing the burden on reporters. Following four years of data collection, however, through this anal ysis we have concluded that MSHA reports can vary to a degree that, while appropriate for mine safety regulation, makes them inappropriate for a robust greenhouse gas emissions monitoring and reporting program

. Furthermore, b eyond the potential variation in the MSHA9

reports , we found that some mines misint erpret the data and incorrectly report to the GHGRP

. Finally,

we note that reporters intending to use MSHA data have stated in a very limited number of cases that they have been unable to obtain the quarterly data from MSHA , and this has delayed submission of their
reports

. 11

We believe the appropriate solution is to remove use of MSHA data as an approved monitoring
method for reporting methane liberated from ventilation systems. We understand that this would present an additional burden to approximately 50% of the reporting mines that now use the MSHA data, but believe limiting the monitoring options to grab samples and CEMS will provide the EPA, the U.S.
Government and the public with more consistent and reliable data from which to formulate policy options for greenhouse gas reporting and management from coal mines.

While we encountered inconsistencies in some GHGRP report s using MSHA data, we emphasize
that our concerns over use of MSHA data are not concerns about the accuracy of the MSHA sampling
method s or sampling locations outlined in the MSHA Coal Mine Safety and Health General Inspection
Procedures Handbook . On the contrary, we believe that the MSHA sampling methods set forth in the Inspection Handbook achieve MSHA’s principal objective of assuring the health and safety of mine
workers. These methods are sufficient for GHG reporting where applied and reported consi stently ; therefore, we recommend that the EPA continue to reference the MSHA Inspection Handbook as the appropriate guidance for taking grab samples under Subpart FF.

11 Designated Representatives for 2 unverified reports in 2014 have made this claim.10

Figure 1: Summary of MSHA data for Mine A based on quarterly reports submitted

Note that there are a different number of measurements in each quarter. There is little consistency between quarters. Q1 has one measurement, Q2

- 11, Q3

– 8, Q4

– 2. Also, the labeling of the shafts/monitoring points do not appear to relate to one another , and
cannot be linked without assistance from the mine.11 Figure 2 : Comparison of data submitted for CH 4 liberation from mine ventilation systems and MSHA data in the same reporting year at Mine B12

Figure 3 : Comparison of data submitted for CH 4 liberation from mine ventilation systems and MSHA

data in the same reporting year at Mine C