NH3 Monitoring in the Upper Green River Basin, 

John V. Molenar1

H. James Sewell2

Jeffrey Collett3

Cassie Archuleta1

Mark Tigges1

Florian M. Schwandner3

Suresh Raja3

1 Air Resource Specialists, Inc

2 Shell Exploration & Production Company

3 Department of Atmospheric Science, Colorado State University

Background image courtesy of: Dave Bell Photos • PO Box 1738 • Pinedale, WY 82941 ww.davebellph
• Background: oil & gas develop

Background: oil & gas develop

in Upper Green River Basin

• Monitoring & Laboratory Proce• Results & Interpretation
Upper Green River Valley

Nestled between the high peaks of western Wyoming's Wind River, Gros Ventre and Wyoming Ranges, the valley is home to: More than 100,000 big game animals Largest mule deer herd in U.S. Continental America's longest big game migration route and a crucial link to the Greater Yellowstone Ecosystem (GYE) Ecosystem (GYE)Largest publicly-owned big game winter range in the GYE One of the west's last best sage grouse habitats and a world-class fishery One of the largest natural gas reserves in the U.S. 
Uncoln 

County 

Tecon County r---=----:- Sub,.,. County 

Brldget' eton Na;tiol1at.Forest 

Sublett.e County 

Upper Green River Valley 

Oil & Gas Development 

Ftwnont County 

N 

Public Land Ownership County 

Btxeau of Indian AffaU's + 

Bt.reBU ot Land Managem"E!nt 

BU"eau ot Reclamation 

USDA Forest ServiC@ 

State 0 5 10 15 

' 

Miles 


1986
1999
2007
Oil & Gas Emissions

Particulates – roads & disturbed landVOCs – drilling fluids, separation, deh

y ,p ,g dration, produced water, gas 

venting, gas compressionNO

x

– diesel drilling rigs gas diesel drilling rigs, gas

compression, vehicles, flaring
WRAP BART CALPUFF Modeling WRAP BART CALPUFF Modeling

Th I t W k Ai Q lit M d li (IWAQThe In

teragency 

Wor

kgroup on Air 

Quality 

M

o

d

eling (IWAQ

recommends three background values for CALPUFF mode

05 bf f t dl d 0.5 pp

b

for 

fores

t

e

d lan

ds;

1.0 ppb for arid lands; and10 ppb for grasslands.

Most of the western U.S. Class I areas are characterized b

forested lands, qy conse

quentl

y a 1.0 pp g b back

ground amm

was selected for the WRAP RMC BART CALPUFF modeli
WRAP BART CALPUFF Modeling WRAP BART CALPUFF Modeling

The com

plex non-linear sulfate-nitrate-ammonia s

y g

stem is hi

gh

on availability of ammonia - NH

3(g)

SO

2(g) 

↔

H

2SO

4(g)

NH

3(g)+ H

2SO

4(g) 

↔ (NH

4

)

2SO

4(p)

NO

2(g) 

↔ HNO

3(g)

NH

3(g) + HNO

3(g) 

↔ NH

4NO

3(p)
Monitorin

g Plan
Objectives of the Upper Green River 

A i Ai M it i P j Ammonia Air 

Monitoring 

Projec

• measure background ammonia (NH

measure background ammonia (NH

concentration for one year for use in 

visibility analyses visibility analyses

• measure concentrations of other rela

gases and particles to provide informgases and particles to provide inform

about the local nitrogen budget

• att t t id tif th i ttemp

t

to identify the source region

attributable to these gases and parti
Monitoring Constraints Monitoring Constraints

• sam

p gg le at existin

g monitorin

g 

• desire to use well known and 

accept d li d l 

t

e

d sampling an

d analy

protocols

• a priori assumption that NH3 would be at low concentration• cost
lo 

• 

Legend 

,L AT Monilor ·+ --lllbjor Roads 

r -. -.....: ;.....;H-i • O&G Wells 

T Compressor Sta1ion 

• 
Monitoring: Instrumentati

• URG dual annular denuder system (Model 3000

mounted at a sample height of 1.5 meters

• A dual channel URG denuder/filter pack sample

to collect samples of ambient trace gas (ammonacid d it t ) d PM id, and nitrate) and PM l i( 

2.5 aerosol species (am

nitrate, and sulfate)

• The prepared denuder/filter pack set is shipped 

The prepared denuder/filter pack set is shipped 

operator on a weekly basis, who installs it into thsampler according to a defined twice-weekly sch

results in alternating 3 results in alternating 3-day and 4 day and 4-day integrated 

day integrated 

• The spent denuder/filter pack is shipped to the 

atmospheric science laboratory at CSU. atmospheric science laboratory at CSU.
Ai Q lit St ti

Air Temperature

Air Quality Station

Ammonia Sampler

Air Temperature

Controlle

Temperature-Controlled Housing for Denuders and Filters

Ship

for Denuders and Filters

Controller Housing

PM2.5 Size-Selective Inlets
Laboratory Analyses Laboratory Analyses

• The denuders are extracted immediatel

y 

 

arrival at CSU and the extracts are refrigeuntil further analysis

• The filters are also unloaded immediately 

stored frozen until extraction and analysis

• Samples are analyzed by ion chromatogr

on a monthly basis

• Data is validated according to EPA protoc

and consist of concentrations in and consist of concentrations in

μg/m3 an

g/m3 an

for gases
QCALITY ASSURANCE PROJECT PLAX 

BOCLDER Al\li\IONIA AIR ::\ IONITORi~G PROJECT 

BOU.DER, WYO::\llNG 

Prepared for 

SHELL EXPLOR-\TION & PRODt:CTIO:oi CO:\IPA!'IY 

At1n: H. ].,.. ~well 

4582 Sooth Uh1er Street Parkway, Suite 500 

Denver. CO 80237 

Prepared by 

1g()1 p PoW'It Onvt SUitt E 

Fon Collins. CO 60~~5 

rhone: 7~ ~1 

www.air-rescuroe.cotn 

April 200S 
R lt esu

s
2.0

NHS

1.01.5

ntration / ug m-3

0.00.5

5

22

29

/529

26

/2

/96

23

/2

/96

23

30

/63

20

27

/418

25

/1

/85

22

29

/63

20

27

/307

24

31

/74

21

28

/529

26

/2

/9

conce

n

12/1

12/

2

12/21/

1/1

1/1

1/

22/ 2/

2/1

2/

23/ 3/

3/1

3/2

3/34/

4/1

4/

2

4/25/

5/1

5/1

5/

26/ 6/

6/1

6/

2

6/27/

7/1

7/

2

7/28/

8/1

8/1

8/

2

8/39/

9/1

9/

2

9/2

10/

10/1

10/1

10/

2

11/

11/

date 2006-2008

gas-particle partitioning NH4 + (

123

ug m-3

NH4 + (SO4 2- HNO3 (

PM

-1

0

d

concentration / 

GAS

-2

12/15

12/29

1/12

1/26

2/9

2/23

3/9

3/23

4/6

4/20

5/4

5/18

6/1

6/15

6/29

7/13

7/27

8/10

8/24

9/7

9/21

10/5

10/19

11/2

11/16

start date
Monthly Average Concentrations 

12 

1.1 -- N03' (p) 

--SO/'(p) 

1.0 - NH;(p) 

0.9 - HN03 (g) 

- NH, (g) ppb 

0.8 

0.7 

0.6 

0.5 

OA 

0.3 

02 

0.1 

t · 

Dec06 J3n07 Feb o7 Mar07 Apr07 May07 Jun07 Jul 07 Aug07 Sep07 Oct07 Nov 07 Dec07 JanOS Feb08 Maroa 
2.0 == 20 NH nt ly stat istics------------------------------~::stde ~ annual average: -

0.24 ± 0.31 ppbv (min: 0, max: 1.55) 

- •mean -
Neutralization

• Convert mass to molar values Convert mass to molar values• Ratio [NH

+] / [NO

-] + 2[SO 2+

• Ratio [NH

]

4

]

/ [NO

3

]

+ 2[SO

4

]

• Then:

ratio = 1 fully neutralized

ratio < 1 acidic < 0.5 very ratio > 1 excess NH

4

+ ratio

>

1 excess NH

4
Monthly Average Ion Concentrations (

μmole/m

3

)

0 0250.030

NO3

- (p)

SO42- (p)

es/m3 0.015

0.0200.025 SO4 (p)

NH4

+ (p)

μmol

0.0050.0100.015

Dec 06 Jan 07 Feb o7 Mar 07 Apr 07 May 07 Jun 07 Jul 07 Aug 07 Sep 07 Oct 07 Nov 07 Dec 07 Jan 08 

0.000

1.2

O3

- 

+ 2SO4

-2) 

1.01.1

Other Ammonium 

Salts?

o: NH4

+ / ( NO

0 70.80.9

Acidic Sulfate

Othe

of N

Dec 06 Jan 07 Feb o7 Mar 07 Apr 07 May 07 Jun 07 Jul 07 Aug 07 Sep 07 Oct 07 Nov 07 Dec 07 Jan 08 

ratio

0.60.7 Acidic Sulfate 

Episode ?

Acidic Sulfate

All ions Episode ?

very low
05 ,---------------------------------------------------------~~-----------------. 

Boulder, Wyoming Particulate Ions ~ole/m 

-- No3·(p) 

0.04 --so;

2

(p) 

--T- NH.' (p) 

0.03 

0.00 

D J an 07 Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J an 08 Feb Mar Apr 

.,. 1.8 0 

(f) 

N 1.6 

+ 

M 1.4 

0 

6 12 ............ .... .......... . . . . . . . . . . . . ...... . ... 

- 1.0 .,. ............ I 

z 0.8 

0 0.6 ~ 

0::: 0.4 ~ 

ro 

0 02 ~ D J an 07 Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J an 08 Feb Mar Apr 
May, 2007 Sulfate Episode

907080 hourly bsp

hourly rhAverage Sulfate Ion

rh (%) 50

6070

bsp (Mm-1) or 

304050102030

May 10 May 11 May 12 May 13 May 14 May 15 May 16 May 17 May 18 May 19 Ma

10 

Neutralization = 0.94 Neutralization = 0.34 Neutralizatio
-- NH3 (g) 

0.04 -- HN0 3 (g) 

0.03 

0.02 

0.01 

0.00 

D Jan 07 Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan 08 Feb Mar Apr 

.,. 1.8 0 

(f) 

N 1.6 

+ 

M 1.4 

0 

6 12 ............ .... .......... . . . . . . . . . . . . ...... . ... 

- 1.0 .,. ............ I 

z 0.8 

0 0.6 ~ 

0::: 0.4 ~ 

ro 

0 02 ~ D Jan 07 Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan 08 Feb Mar Apr 
Source Regions
Residence Time Analys

Residence Time Analys

• Ammonia weighted back trajectories were used to identify th

geographic source areas most likely to contribute to the highgeographic source areas most likely to contribute to the high

measured ammonia days. 

• Trajectories were generated using the Hybrid-Single Particle 

I t t d T j t (HYSPLIT) d l d l d b th N In

tegra

t

e

d

Trajec

tory (HYSPLIT) mo

d

el develope

d

by the 

N

Oceanic and Atmospheric Administration’s (NOAA) Air ResoLaboratory (ARL). Detailed information regarding the trajecand these data sets can be found on NOAA’s Web site 

(htt // l / d /h lit4 ht l http://www.arl.noaa.gov

/rea

d

y/hysplit4.ht

ml).

• Three back trajectories were generated per day, including e

0400, g 

 1200 and 2000 MST and end hei

ghts of 100 m. Each 

along a 72-hour back trajectory paths was weighted with meammonia concentration corresponding to the end date of eatrajectory. The ammonia values associated with each hourlthen summed and normalized into 1/4 de

g g ree horizontal 

grid 

latitude and longitude. 
• 

I 

Boulder, WY 

2007 

NH3 Weighted 

Residence Time (%) 

< 0.01 

0.01 -0.02 

0.02-0.04 

0.04-0.08 

• 0.08-0.16 

• 0.16-0.32 

• >0.32 

Conclusions

• NH

3 concentrations are highly seaso

concentrations are highly seaso

dependent. Ranging from near deteclimits Dec-Feb, to peak values of 1.5 

d i th ur ng the summer.

• 2007 average NH 2007 average NH

3 was 0 24 ppb was

0.24 ppb

• Residence time anal

ysis indicates th

transported into the region primarily west along the Snake River Valley anSouthwest along the Wasatch front. Southwest along the Wasatch front.