Results you can rely on

Why Methane Matters

Gary T. Hunt

Vice President and 

Principal Scientist

TRC Corporation

Lowell, MA 01854

Oil & Gas Environmental 

Compliance Conference

Washington, PA

May 13-14, 2014
Results you can rely on

Topics of Discussion

• Atmospheric Science

• Sources of Methane

• Regulatory Climate – Natural Gas Production 

(Unconventional or Shale)

• White House Strategy to Reduce Emissions

• European Perspective

• Colorado Air Regulations

• Debate and Controversy

• Significant Field Studies

• Closing Thoughts

• References

• Questions

2
Results you can rely on

Why Methane Matters!!

•

3
Results you can rely on

Why Methane Matters? 

Atmospheric Science [1,5,10]

4

20 – 25 Times > GWP of CO2 over next 100-year term

72 Times > GWP of CO2 in first 20 years

Atmospheric lifetime of 10-12 years 

Oxidizes to CO2 and water via reaction with OH-Radical

Concentrations have risen 250% over the period 1750 – 2011 

(700 ppb and 1874 / 1758 ppb)

Background now 1.9 ppm (v/v) (200 Times < CO2)

OH-Radical Levels Decreasing

CH4 Levels highest in past 420,000 years
Results you can rely on

Global Warming Potentials and

Atmospheric Lifetimes (Years) [4]

Gas Atmospheric Lifetime GWPa

CO2 50-200 1

CH4 12±3 21

N2O 120 310

HFC-23 264 11,700

HFC-32 5.6 650

HFC-125 32.6 2,800

CF4 50,000 6,500

C2F6 10,000 9,200

SF6 3,200 23,900

5

 Source: (IPCC 1996)

a100-year time horizon

The GWP of CH4 incudes the direct effects and those indirect effects due to the production of tropospheric ozone 

 and stratospheric water vapor. The indirect effect due to the production of CO2 is not included.
Results you can rely on

Sources of Methane Emissions in the 

United States, 2011 [3]

6

*37% of NG Emissions associated with production or 8.9% of Total
Results you can rely on

CH4 Emissions U.S. Regulatory Climate

7

CH4 specifically not regulated historically

Not typically classified as a volatile organic (VOC)

VOC typically defined as Non-Methane Hydrocarbons (NMHC)

CH4 not addressed in final rule NSPS Subpart 0000 (April 2012)

Excluded from NSPS and NESHAPS Shale Gas Production Wells 

(77 CFR, 49, 490, August 2012)

States Debate – “Sue and Settle” Controversy

White House Methane Reduction Strategy (March 2014)

Colorado Air Rules (Feb 2014)

40 CFR Part 98 Subpart W – (March 10, 2014)
Results you can rely on

Civil Strife – State Rivalry!!!

EPA Regulation of CH4 Emissions from 

Oil/Gas Operations Under NSPS

PRO* CON**

New York*** Alabama Ohio

Connecticut Arizona Oklahoma

Delaware Indiana South Dakota

Maryland Kansas Texas 

Rhode Island Montana West Virginia

Vermont Nebraska Wyoming

Massachusetts North Dakota

8

 *NE States informed EPA of their intent to sue EPA 12/11/2012. Notice of Intent to Sue.

**Signed May 2, 2013 letter cautioning EPA regarding “friendly” negotiations between Agency and 

 NE States (“Sue and Settle”).

***Moratorium currently in place
Results you can rely on

Colorado Air Regulations [16] 

(Adopted 2/23/14)

• First rule to classify methane and ethane as regulated 

pollutants

• Rules passed with little consideration of industry 

comments (Colorado O&G Association)

• Regulate hydrocarbon emissions from storage tanks, 

well production facilities, and compressor stations

• Compliance deadlines as early as May 2014

• NSPS 0000 enforcement now at state level

• “Ripple” effect concerns – influencing other state 

programs

9
Results you can rely on

Colorado Rule – Some Key Features

• De minimis thresholds for all non-criteria reportable 

pollutants set at 250 lbs/year and Air Pollution Emission 

Notice (APEN) now required.

• Auto igniters required on all emissions control combustion 

devices both existing and new.

• LDAR programs for well production facilities and compressor 

stations.

• Storage Tank Emissions Management (STEM).

• Creates Approved Instrument Monitoring Methods (AIMM) 

and inspection schedules.

• AIMM includes IR camera, EPA Method 21 and AVO (Audio, 

Visual and Olfactory)

10
Results you can rely on

11

White House Strategy to Reduce Methane Emissions 

(March 2014) Relevance to NG Production [14]

Some Features

• Executive Orders – no 

congressional legislation !!!

• Interior department 

standards to reduce venting 

and flaring of methane from 

O&G production on public 

lands.

• Improved methane 

measurements –

atmospheric concentrations, 

emissions measurement and 

inventories.
Results you can rely on

White House Strategy to Reduce Methane Emissions 

(March 2014) Relevance to NG Production [14]

• Working with states – DOE/EPA provide technical 

assistance to support policy to reduce emissions.

• Enhanced partnerships and stakeholders 

engagement – e.g., DOE roundtable discussions 

(industry, states, academia, non government 

organizations and labor).

• EPA bolster voluntary NG Star Program – identify 

cost-effective technologies and practices that reduce or 

avoid CH4 emissions.

12
Results you can rely on

White House Strategy to Reduce Methane Emissions 

(March 2014) Relevance to NG Production [14]

• DOE will support development of new technologies.

• Identify policy recommendations for emissions 

reduction from energy infrastructure - (gas 

production, transmission, storage and distribution of 

supply chain).

• Prioritize pipeline safety - (PHMSA) - state program 

survey – replace old cast iron pipes with new 

technology.

13
Results you can rely on

European Perspective (October 2013)

Shale Gas Production [9]

Europe considering a Methane Emissions 

Ceiling under EU Law. Revised National 

Emissions Ceilings Directive (NECD)

Shale Gas Companies in Europe will have 

to monitor and account for methane 

emissions at drill sites or face regulations, 

(Joseph Delbeke, EU Climate Head)

“Companies are going to put it on the table 

or a regulation is going to come..... we 

must know what the methane emissions 

are going to be.” (J.Delbeke)

14
Results you can rely on

U.S. Industry and Shale Gas

Advocates Perspective

EPA NSPS Rules have been proven effective “EPA got it right”

Additional NSPS to address CH4 not warranted. Current NSPS and 

NESHAPS are resulting in CH4 emissions reduction (control/capture) [6]

30% of US NG currently attributable to fracturing of shale 

formations; 50% by 2040 [7]

Use of NG versus coal/oil provides net GHG benefit 

(CO2 Reduction)

15
Results you can rely on

Shale Gas vs Coal GHG Impacts

Comparison and Controversy

16

GHG advantage disappears if 1% of 

CH4 is lost during NG production [7]

GHG advantage lost at 3-4% fugitive 

emissions [8]

Shale Gas footprint 20-200% (2 times) 

> than coal over 20-year term [11]

Footprints comparable over 

100-year term [11]
Results you can rely on

Fugitive CH4 Emissions Comparison of Estimates

(Expressed as % of CH4 Produced over Well Lifetime)

Study/Source

Type

Results

In % Comments Reference

EPA 2011 GHG 

Inventory 0.47 Relies on engineering calculations. USEPA Feb. 2013 [3]

UT/EDF 2013 0.42 Field measurements small population 

of sources.

PNAS 2013 Allen, 

et al [6]

Cornell/Howarth 1.7-6.0 Conventional Gas Wells only 

(0.01% well completion)

Howarth, et al 

2011 [11]

Cornell/Howarth 3.6-7.9 Shale Gas Wells only (1.9% well

completion) Conservative (Author)

Howarth, et al

2011 [11]

NOAA Utah 6.2-11.7

Based on hourly gas production rate 

from a single well on one day. 

Aircraft measurements with positive 

bias likely from non-well sources.

NOAA [13]

17
Results you can rely on

UTEXAS/EDF Study CH4 Emissions

Shale Gas Production [6]

18

Some Features/Findings

 Direct field measurements at production sites.

 Well completion emissions far below prior EPA 

estimates.

 NSPS/NESHAPS regulated sources showed most 

dramatic reductions.

 EPA NSPS and “Green Completion” control 

technology credited.

 Emissions beyond well site > EPA estimates 

(unregulated sources).
Results you can rely on

National Emission Estimates for the

Natural Gas Production Sector [6]

Category

2011 EPA GHG

Inventory Net Emissions,

*Gg of Methane/yr

Emission estimates from UT 

PNAS Report Gg of 

Methane/yr

Completion flowbacks from 

wells with hydraulic fracturing 654 18 (5-27)

Chemical pumps 34 68 (35-100)

Pneumatic controllers 355 580 (518 – 826)

Equipment Leaks 172 - 211 291 (186-396)

Subtotal, Natural Emissions

(All Above Categories) 1215 - 1254 957 ± 200

19

Total methane, Gg

Methane emissions, *% [percent 

of gross gas production]

2,545

0.47% [0.59%]

2,300

0.42% [0.53%]
Results you can rely on

UTEXAS/EDF Study [6]

The Critics Point of View “Frackademia”

 Sample population too small (only 150 Shale Production Sites) 

[12]

 Not representative on industry-wide basis (489 wells vs 446,745 

in EPA 2011 GHG Inventory) [2,3]

 Extrapolation of data industry wide not valid [12]

 Sites selected by petroleum industry sponsors 

(9 drilling companies) [7,12]

 90% funds provided by petroleum companies [12]

 “Best Case” emissions scenario (Howarth/Cornell)

 Study authors career ties to oil industry.

20
Results you can rely on

CH4 Emissions From Shale Gas Development 

Marcellus Region of SW Penn - April 2014 PNAS [15]

• Purdue and Cornell researchers

• “Top Down” approach – aircraft measures gas levels in air above 

well

• Wells found with high emissions were in “drilling” stage (<1% of 

total # in region)

• Drilling (pre-production) not well represented in current inventories

• Regional CH4 flux (2.0 – 14 g/skm2) statistically equivalent to EPA 

“bottom up” inventory (2.3 - 4.6 g/skm2)

• Seven (7) well pads (drilling stage) 34 g/s emission rate represents 

4-30% of regional flux

• EPA “bottom up” estimates for drilling releases range from 0.04 –

0.30 g/s (100-1,000 times lower)

21
Results you can rely on

• Develop cost-effective CH4 sensing technology.

• Improve US greenhouse gas inventory methodology –

(calculations, emission factors, higher quality data 

reporting).

• Expand national methane ambient monitoring network 

(NOAA).

• Improve local/regional emissions modeling – DOE 

sponsored measurement programs in Marcellus region 

of Penn (Penn State and Carnegie Mellon).

22

White House Strategy to Reduce Methane Emissions 

Methane Measurement Action Plan [14]
Results you can rely on

Emissions Estimates in Pennsylvania Marcellus 

Region – Using Atmospheric Inversion

Some Features

 DOE sponsorship

 Jointly conducted by Penn State and NOAA

 Quantify fugitive CH4 emissions from Marcellus 

shale gas production region (2014-2016)

 Multiple measurement platforms (aircraft, fixed 

towers and ground vehicles)

 Use of carbon isotopic signatures and tracer gas to 

differentiate CH4 sources

23
Results you can rely on

Emissions Estimates in Pennsylvania Marcellus 

Region – Using Atmospheric Inversion

• Use of IR based laser diode (Cavity Ring Down 

Spectroscopy).

• “Top down” approach based upon ambient 

measurements in combination with meso-scale 

atmospheric inversion modeling.

• Source specific data collected to develop CH4

emissions map “bottom-up”.

• Develop refined emission factors (EF) for use in new 

inventories and for comparison to existing EF and 

inventories.

24
Results you can rely on

25

The Methane Matter!!!

Some Closing Thoughts

Debate and controversy continue

The regulatory climate has “heated up”

Much needed field measurements now available or in progress; and 

more planned

Fugitive CH4 = lost $

Consider voluntary self audits of gas production sites

Actual industry-wide emissions somewhere between 0.42 and 7.9%

Further CH4 regulations imminent, both federal and in certain states 

(Colorado Copy Cats !!!!)

Watch out for White House Executive Orders inviting EPA actions
Results you can rely on

Thank You For Your Attention !

26

Contact Information:

Gary Hunt, Vice President and Principal Scientist

TRC Corporation

650 Suffolk Street

Lowell, MA 01854

978.656.3551 (w)

ghunt@trcsolutions.com
Results you can rely on

References

1) Leveraging Natural Gas to Reduce GHG Emissions, Center for Climate and 

Energy Solutions, June 2013.

2) USEPA, Draft U.S. Greenhouse Gas Inventory Report, 2013; 

http://www.epa.gov/climatechange/ghgemissions/usinventoryreport.html 

3) Draft Inventory of U.S. Greenhouse Gas Emissions and Sinks: USEPA, 

1990 – 2011, February 11, 2013.

4) IPCC (1996) Climate Change 1995: The Science of Climate Change 

Intergovernmental Panel on Climate Change. J.T. Houghton, et al. Cambridge 

University Press, Cambridge, U.K.

5) Methane Hydrates and Contemporary Climate Change, Nature Education 

Knowledge, 3(10):29, Carolyn Ruppel, 2011.

6) Measurements of Methane Emissions at Natural Gas Production Sites in the 

U.S., D.T. Allen, et al. Proceedings of the National Academy of Science (PNAS), 

USA, 2013, DOI: 10.1073/PNAS 1304880110.

27
Results you can rely on

References (cont’d)

7) “Chasing Methane” Chemical and Engineering News, September 30, 2013, 

Volume 91, Number 39, page 24.

8) New York Times, September 16, 2013, “Gas Leaks in Fracking Disputed in 

Study.”

9) Euractiv (www.Euractiv.com), October 8, 2013.

10)Recent Greenhouse Gas Concentrations, DOI: 10.3334/CDIA/ATG.032, 

February 2013, T.J. Blasing, U.S.DOE and Oakridge National Laboratory.

11)“Methane and the Greenhouse Gas Footprint of Natural Gas from Shale 

Formations”, R.W. Howarth et al., Climatic Change DOI: 10.1007/S10584-

011-0661-5, 2011.

12)“Frackademia”: The People and Money Behind The EDF Methane Emissions 

Study, September 17, 2013. www.commondreams.org

13) NOAA’s One Day of Data Falls to Quiet Critics, August 7, 2013. 

http://theenergycollective.com/

28
Results you can rely on

References (cont’d)

14) White House “Climate Action Plan – Strategy to Reduce Methane Emissions” 

March 2014.

15) “Toward a Better Understanding and Quantification of Methane Emissions 

from Shale Gas Development” Carlton, Shepson et al. (Purdue, Cornell, 

NOAA, U Colorado and Penn State) Proceedings of the National Academy of 

Science April 14, 2014.

16) Revisions to Regulations 3, 6 and 7 (February 23, 2014) Colorado Air Quality 

Control Commission.

29