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) emissions 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 requires reporters to monitor 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 performed 

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, the EPA tasked ARI 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 shafts. The assessment included a review of MSHA sampling and reporting 

procedures, 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 greenhouse 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 

occurred, 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 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 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 

methods or sampling locations outlined in the MSHA Coal Mine Safety and Health General Inspection 

Procedures Handbook1. 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 reporting 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 underground 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 States with total air throughput greater 

than 1 million cubic feet per minute. In general, MSHA mandates that maximum CH4 concentrations in 

a mine ventilation shaft not exceed 1 percent, except for high concentration “bleeder” shafts (nonman/material shafts) which can operate at up to 2 percent CH4. 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.pdf
3

low in ventilation shafts, the sheer volume of air flow through the shafts results 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 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) emissions to EPA’s Greenhouse Gas Reporting 

Program (GHGRP) under 40 Code of Federal Regulations (CFR) Part 98. The Greenhouse Gas Reporting 

Rule was promulgated in response to the FY2008 Consolidated Appropriations Act (H.R. 2764; Public 

Law 110-161) which requires reporting of greenhouse gas (GHG) data and 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 reporting 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), and 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, 20093in 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 Administration (MSHA) 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 public comment period, the EPA included a third monitoring 

option in the final rule published on July 12, 20105- Continuous Emissions Monitoring Systems (CEMS). 

Table 1 shows the breakdown of monitoring options chosen by Subpart FF reporters since reporting 

began.

 

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 98.324
4

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 on

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 2015
5

Table 2: Example of quarterly emissions data supplied by MSHA

Sample Data from 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 differences 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 methane 

liberation from mine ventilation shafts. 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 most significantly. Several 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 sampling procedures

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 measurements capture methane (CH4) 

concentration and volumetric flow in approaches to exhaust shafts, and, in some cases, measurements 

are taken at intake shafts. Inspectors take CH4 concentration measurements following a published 

MSHA protocol (MSHA Coal Mine Safety 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 this 

may include roadways, belt conveyor entries, and/or other areas where air leaves the mine.”10 Air 

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 for five gases: CH4, carbon dioxide (CO2), oxygen (O2), 

ethane (C2H6), and nitrogen (N2). Inspector use 10-milliliter (ml) air sample bottles or ‘vac-u-tainers®’ 

to collect the samples. Air flow measurements are taken with hand-held anemometers or pitot tubes. 

For vertical exhaust shafts (a.k.a., upcast shafts ), MSHA inspectors take the measurements in 

approaches. Approaches are underground roadways leading to an upcast exhaust shaft, and an exhaust 

shaft may have multiple approaches. Although the MSHA 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. 

Measurements 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 per day may be considered a mine with 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 mine operators may be notified if there are potential safety 

concerns. The report will show each approach or intake shaft measured during the quarter, and for 

each approach or intake shaft:

o Date of measurement

o Bottle number for the CH4 sample

o CH4 concentration the air flow measurement in cubic feet per minute

o Cubic feet of methane in a 24 hour period based on the CH4 concentration and air flow 

measurements.

MSHA may increase the frequency of inspections 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 

measurement frequency is quarterly. 

*Note - Total methane liberation calculated 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 CH4 concentrations reach levels of concern or when total methane liberated by the mine meets 

certain benchmarks. However, MSHA will provide the quarterly report should the operator request it. 

5.0 Potential problems with use of MSHA data for reporting 

greenhouse gas 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 have 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 concerns with 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 presented 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. Therefore, 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 approaches 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 confusion and uncertainty to the review 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 monitoring points in the GHGRP reports do not match up 

exactly with the MSHA quarterly 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 CH4% 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 CH4

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 instances, 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 problems 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 from 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. In 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 analysis 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, beyond the potential variation in the MSHA 
9

reports, we found that some mines misinterpret 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 reports using MSHA data, we emphasize 

that our concerns over use of MSHA data are not concerns about the accuracy of the MSHA sampling 

methods 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 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. 

 

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

shaft/monitoring point Quarter Date of measurement flow rate (acfm) concentration (%)

150FT INBY MAIN FAN - RETURN 1 2/22/2012 748,295.00 0.45

15 EAST - IMMEDIATE RETURN - TAILGATE XC 25 2 4/3/2012 21,262.00 0.04

14 EAST - 2% POINT - UPPER - ENTRY 2 2 4/9/2012 117,420.00 2.13

14 EAST - LOWER - 2% POINT - ENTRY 1 2 4/9/2012 113,825.00 2.06

16 EAST - MMU 004 - IMMEDIATE RETURN 2 4/9/2012 50,723.00 0.01

MAINS - IMMEDIATE RETURN 2 4/10/2012 57,888.00 0.33

17 EAST - IMMEDIATE RETURN 2 4/10/2012 51,408.00 0.13

150FT INBY MAIN MINE FAN 2 4/12/2012 685,990.00 0.72

78 XC - NORTH MAINS - 13 1/2 EAST - 2% POINT 2 4/30/2012 172,260.00 2.41

79 XC - NORTH MAINS - 13 1/2 EAST - 2% POINT 2 4/30/2012 48,938.00 2.31

2% POINT @ XC 78 - RT RETURN - N-MAINS 2 4/5/2012 210,210.00 1.74

15TH E - 2% POINT - LOWES SIDE 2 4/24/2012 46,400.00 2.04

RETURN ENTRY - 9 1/2 EAST SECTION 3 7/17/2012 62,900.00 0.02

150' INBY MAIN FAN - RETURN 3 7/17/2012 741,000.00 0.33

RETURN ENTRY - 10 EAST SECTION 3 7/17/2012 60,800.00 0.02

17 EAST IMM RETURN 3 8/1/2012 38,080.00 0.06

13 1/2 EAST STRAIGHT 2% POINT 3 8/16/2012 173,320.00 1.76

13 1/2 EAST XC #1 2% POINT 3 8/16/2012 858.00 1.1

11 EAST SECTION IMM RETURN 3 8/16/2012 44,250.00 0.03

STRAIGHT 2% POINT 13 1/2 EAST 3 8/29/2012 144,200.00 2

Main return aircourse - 150' inby main fan. 4 10/10/2012 721,427.00 0.49

!st West Mains Section Return Entry 4 10/18/2012 43,500.00 0

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 CH4 liberation from mine ventilation systems and MSHA data in 

the same reporting year at Mine B 

Mine B

GHGRP Report for Reporting Year X

Date Vent Monitoring Point CH4%

Volumetric Air Flow

(cfm)

2/6/2012 RETURN SHAFT - NORTH 0.10 28,044 

2/6/2012 RETURN SHAFT - WEST 0.10 34,483 

3/23/2012 BLEEDER SHAFT 0.43 240,360 

3/23/2012 SLOPE 0.01 119,800 

3/25/2012 BELT BLEEDER 0.21 59,160 

4/16/2012 BLEEDER SHAFT 0.34 328,200 

4/25/2012 SLOPE 0.09 103,275 

5/8/2012 BELT BLEEDER 0.13 63,063 

5/8/2012 RETURN SHAFT - NORTH 0.13 6,560 

5/8/2012 RETURN SHAFT - WEST 0.13 6,560 

7/16/2012 BELT BLEEDER 0.20 58,865 

7/16/2012 BLEEDER SHAFT 0.23 136,032 

7/16/2012 RETURN SHAFT - NORTH 0.12 10,200 

7/16/2012 RETURN SHAFT - WEST 0.12 12,600 

7/19/2012 SLOPE 0.11 70,362 

9/10/2012 BLEEDER SHAFT 0.11 136,032 

9/19/2012 SLOPE 0.10 99,600 

10/10/2012 RETURN SHAFT - NORTH 0.14 14,014 

10/10/2012 RETURN SHAFT - WEST 0.15 13,048 

12/4/2012 BELT BLEEDER 0.03 34,144 

MSHA Reports for Reporting Year X

Date Vent Monitoring Point CH4%

Volumetric Air Flow

(cfm)

1/11/2012 NORTH BLEEDER SHAFT - EAST 0.74 191,100

1/11/2012 SOUTH BLEEDER SHAFT - EAST 0.75 40,725

1/11/2012 NORTH BLEEDER SHAFT - WEST 0.25 121,800

1/26/2012 SLOPE 0.08 162,620

1/26/2012 UPCAST - RETURN AIR SHAFT - NORTH SIDE 0.1 54,112

1/26/2012 UPCAST - RETURN AIR SHAFT - WEST SIDE 0.11 54,720

4/11/2012 NORTH BLEEDER SHAFT - EAST APPROACH 0.29 287,378

4/11/2012 NORTH BLEEDER SHAFT - WEST APPROACH 0.21 96,648

4/17/2012 RETURN SHAFT - WEST APPROACH 0.09 990

4/17/2012 RETURN SHAFT - NORTH APPROACH 0.1 12,478

8/6/2012 UPCAST SHAFT BOTTOM NORTH SIDE 10AM 0.11 13,940

8/6/2012 UPCAST SHAFT BOTTOM WEST SIDE 10:05AM 0.11 16,485

8/6/2012 HG 5 BELT FAN WEST SIDE 0940AM 0.16 24,480

8/6/2012 HG 5 BELT FAN EAST SIDE 0930AM 0.14 48,195

8/8/2012 NORTH SHAFT UPCAST EAST SIDE 1005 HOURS 0.74 235,690

8/8/2012 NORTH SHAFT UPCAST WEST SIDE 0950 HOURS 0.18 83,160

10/10/2012 North Shaft East EP 0.73 247,940

10/10/2012 North Shaft West EP 0.16 81,480

10/12/2012 Long Wall #5 Belt Upcast Shaft, Outby side. 0.07 24,368

10/12/2012 Long Wall #5 Belt Upcast Shaft, Inby side. 0.03 39,169

10/12/2012 Main Upcast Fan, North Side. 0.14 18,860

10/12/2012 Main Upcast Fan, West Side. 0.14 18,840

10/12/2012 Slope Entry, 50 feet in from collar. 0.04 33,000

Names are similar but

still do not match up 

exactly to MSHA report

CH4% and Air Flow do 

not match up to MSHA 

report
12

Figure 3: Comparison of data submitted for CH4 liberation from mine ventilation systems and MSHA 

data in the same reporting year at Mine C

Mine C

GHGRP Report for Reporting Year X

Date Vent Monitoring Point CH4%

Volumetric Air Flow

(cfm)

1/10/2012 PORTAL #2 UPCAST NORTH SIDE 0.22 266,688

7/10/2012 PORTAL #2 UPCAST NORTH SIDE 0.22 313,038

MSHA Reports for Reporting Year X

Date Vent Monitoring Point CH4%

Volumetric Air Flow

(cfm)

3/30/2015 PORTAL #1 UPCAST - TOTAL LIBERATION - SOUTH SIDE 0.31 252,495

3/30/2012 PORTAL #2 UPCAST - TOTAL LIB - WEST SIDE 0.31 205,100

3/30/2012 PORTAL #1 UPCAST - TOTAL LIBERATION - WEST SIDE 0.24 211,248

3/30/2012 PORTAL #2 UPCAST - TOTAL LIB - NORTH SIDE 0.24 238,275

3/30/2012 PORTAL #2 UPCAST - TOTAL LIB - SOUTH SIDE 0.44 158,895

7/10/2012 PORTAL #2 - UPCAST -WEST SIDE (RETURN) 0.25 329,040

7/10/2012 PORTAL #2 - UPCAST - NORTH SIDE (RETURN) 0.22 313,038

7/10/2012 PORTAL #2 - UPCAST - SOUTH SIDE (RETURN) 0.31 198,585

7/11/2012 PORTAL #1 WEST SIDE UPCAST 0.06 179,488

7/11/2012 PORTAL #1 SOUTH SIDE UPCAST 0.09 223,525

10/3/2012 Portal #2 North Side Return 0.24 379,916

10/3/2012 Portal #1 South Side 0.08 421,867

10/3/2012 Portal #1 West Side 0.07 210,184

10/3/2012 Portal #2 West Side Return 0.30 283,920

10/3/2012 Portal #2 South Side Return 0.25 249,501

Only 2 measements

reported to the GHGRP

For Q3 monitoring 2 

approaches left out of 

GHGRP Report