Jeff CollettDepartment of Atmospheric Science

Colorado State University

People• CSU Atmos Sci: Arsineh Hecobian, Tony Prenni, Yi Li, Andrea

Clements, Ashley Evanoski, Jeff Pierce, Brad Wells, KiraShonkwiler, Landan MacDonald, Florian Schwandner, Suresh Raja

• CSU Soil and Crop Science: Jay Ham

• NPS/CIRA: Bret Schichtel, Jenny Hand, Derek Day, Bill Malm

• ARS: Mark Tigges, Stephen Holcomb, Cassie Archuleta, Lincoln Sherman, Bryan Bibeau

• Shell: Jim Sewell, Angela Zivkovich

Funding• Garfield County

• CDPHE

• National Park Service

• Shell, Encana, WPX Energy, Bill Barrett Corp., Ursa Resources

While natural gas offers a

cleaner-burning alternative

to combustion of other fossil

fuels, air emissions are

associated with its

production and distribution

Criteria Pollutants

• O3 (VOC + NOx + sunlight)

• PM2.5

Hazardous Air Pollutants

/ Air toxics

• Diesel particulate matter

• Benzene, toluene,

ethylbenzene, xylenes

Climate• CH4

• Black carbon

Source: U.S. Energy Information Administration (EIA)

• Characterization of source specific air toxics, ozone precursors, and CH4

emissions and their near-field dispersion– Garfield County, CO

– North Front Range

• Local-to-regional

scale impacts on air

quality, including PM

formation and haze– Boulder, WY

– Bakken, ND W. Malm

Garfield County Study(2012-2015)

Front Range Study(2013-2016)

Source: http://pubs.usgs.gov/dds/dds-069/dds-069-p/REPORTS/69_P_CH_2.pdfSource: COGCC

Characterize emissions and downwind

dispersion of

• air toxics (e.g., benzene, toluene, ethylbenzene and

xylenes (BTEX)

• ozone precursors (VOCs and NOx)

• methane

Cooperate with industry to gain

• full site access

• activity information

Focus on

• new wells in Garfield County

• new wells and production emissions(Front Range)

Preparation of Well

Pad

Well Drilling

Hydraulic

Fracturing

Well Completion

Flowback

Objectives

• Quantify emissions of chemical

compounds (air toxics, ozone

precursors, NOx, and methane) during

new well development

• Characterize how these compounds are

dispersed in the atmosphere downwind

of the site

• Produce a peer-reviewed, public

dataset of high quality emissions data

Source of Figures: http://lingo.cast.uark.edu/LINGOPUBLIC/natgas/wellprep/index.htm

Study team

• Colorado State University

Jeff Collett, PI

Jay Ham, co-PI

• Air Resource Specialists, Inc.

Technical Advisory Committee

• Representatives from industry, CDPHE,

USEPA, NCAR, BLM

Operations Committee

Sponsors

• Garfield County

• Encana, WPX Energy, Bill Barrett Corp.,

and Ursa Resources

Emissions determined using tracer ratio method

Combination of time-integrated and continuous measurements to observe temporal and spatial variability

Mobile and fixed sampling platforms

Mo

bil

e 4

WD

Plu

me

Tra

ck

er • C2H2

• CH4

• Met

• GPS

CS

U M

ob

ile

La

b • VOCs

• NOX

• CO

• WD & WS data

Inte

gra

ted

Me

asu

rem

en

ts • VOCs

• C2H2

Me

teo

rolo

gic

al

Me

asu

rem

en

ts • Temp.

• RH

• Wind Direction

• Wind Speed

Tracer (acetylene)

released at a known rate

• Must co-locate with source

Measurements

• Real Time: Cavity Ring

Down Spectroscopy

Acetylene and Methane

• Offline: Canister

VOC/tracer ratio at each

point provides an

independent emission

estimate

Multiple models to be used• System for Atmospheric Modeling (research model)

• AERMOD (regulatory model)

Use measured emissions and meteorology to model

concentration field downwind• Compare against field measurements to test model accuracy

Several field deployments completed at

multiple locations• More field work, data analysis, and modeling in 2014/15

Peer-reviewed findings will be released and

available to use in subsequent health impact

assessments, regional air quality assessments,

etc….

Study emphasis is on• Emissions for drilling, fracking, and flowback

• Downwind plume dispersion and concentrations

• Air toxics, ozone precursors, and methane

CSU under contract with State of Colorado

Technical advisory panel finalizing study scope

and measurement priorities• Study methods similar to Garfield County study

• Study scope will include new wells and production emissions

Field measurements to begin in spring 2014

with study completion in late 2016

Industry cooperators and additional funding

being sought

• Nitric acid production• NO + O3 NO2 + O2

• NO2 + OH HNO3

• Ammonium nitrate production– NH3(g) + HNO3(g) <=> NH4NO3(p)

– Particles favored at low T, high RH

• Ammonium nitrate particles– ~200-600 nm– Several days atmospheric

lifetime– Important cause of haze

Natl. Parks Conservation Assn.

Long-term measurements of the NHx-NOx-

SOx system in Boulder, WY

CSU, Air Resource Specialists, Shell

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

HNO3(b)1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

Con

cent

ratio

n (

µg/m

3 )

NH3(a)

2.0

1.5

1.0

0.5

0.0

Con

cent

ratio

n (

µg/m

3 )

NH4+(c) 3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0

NO3-(d)

2.5

2.0

1.5

1.0

0.5

0.0

Con

cent

ratio

n (

µg/m

3 )

SO42-(e) 0.25

0.20

0.15

0.10

0.05

0.00

K+(f)

1.2

1.0

0.8

0.6

0.4

0.2

0.0Ja

n

Feb

Mar

Apr

May Jun

Jul

Aug

Sep Oct

Nov

Dec

N(+V)(h)2.0

1.5

1.0

0.5

0.0

Con

cent

ratio

n (

µgN

/m3 )

Jan

Feb

Mar

Apr

May Jun

Jul

Aug

Sep Oct

Nov

Dec

N(-III)(g)

Ammonia shows typical

summer max

Nitric acid/nitrate shows

unusual winter max tied to

winter photochemical smogLi et al., Atmos. Env., 2013

NH3(g) + NH4+(p) HNO3(g) + NO3

-(p)

3.0

2.0

1.0

0.01.6

1.2

0.8

0.4

0.0

1/1/07 7/1/07 1/1/08 7/1/08 1/1/09 7/1/09 1/1/10 7/1/10 1/1/11 7/1/11 1/1/12Date

2.0

1.5

1.0

0.5

0.0

0.20

0.15

0.10

0.05

0.00

HNO3 (g) NO3- (p)

NH3 (g) NH4+ (p)

Con

cent

ratio

n (µ

g/m

3 )

2007 2008 2009 2010

(a)

(b)

2011

(c) SO42-

K+

K+ C

once

ntra

tion

(µg/

m3 )

Li et al., Atmos. Env., 2013

• Winter fine particle nitrate formation limited by ammonia

availability

• Annual average NH3 mixing ratio = 0.30 ppbv

https://www.dmr.nd.gov/oilgas/

Oil Production in North Dakota

From Jenny Hand, NPS/CIRA

05

101520 Knife River (KNRI)

05

101520

Medicine Lake (MELA)

Bakken Fine Particle ConcentrationsC

on

cen

trat

ion

(µ

g m

-3)

Sampling Date

Episode 1 Episode 2

0

5

10

15

20 Theodore Roosevelt North Unit (THRO-N)Nitrite Chloride Sodium Potassium Magnesium Calcium Ammonium Nitrate Sulfate

05

101520 Fort Union (FOUN)

PM Precursor Gas Concentrations: All SitesC

on

ce

ntr

ati

on

(µ

g m

-3)

Sampling Date

0

5 Fort Union (FOUN)

0

5 Knife River (KNRI)

0

5 Medicine Lake (MELA)

0

5Theodore Roosevelt North Unit (THRO-N)

Sulfur Dioxide Nitric Acid Ammonia

• Ammonia nearly depleted in Theodore Roosevelt

North during episode 1, but not episode 2

• Excess ammonia always available at Fort Union• HNO3 currently limits NH4NO3 formation

1 2

Work underway to measure emissions of air toxics, ozone

precursors, and methane in Colorado

• Emissions quantified for individual processes

Air toxics, ozone precursors, and methane

With operator information about activity during emissions measurement

• Complementary to other “top-down” emission estimates

CSU work in WY and ND focused on oil and gas impacts on

fine particle and haze formation

• NOx controls in Wyoming and limited ammonia prevent large fine

particle/haze episodes

• Bakken pilot study observed sufficient ammonia to permit

substantial NH4NO3 formation

Increased NOx emissions could increase PM and haze formation