Impact of emissions from natural gas production facilities on ambient air quality in the Barnett Shale area: A pilot study

Figures & data

Figure 1. Map of Shale Creek community sampling sites. Markers with black dots inside indicate sites with both passive (NO_x, SO₂, speciated VOCs) and active filter samplers. Other sites had only passive samplers.

Figure 2. Star Shell Road source sample collection site: aerial view showing monitoring site locations. Symbols used are same as Figure 1.

Table 1. Passive sampler types used for saturation monitoring

Manufacturer	Medium Type	Target Pollutants	Analysis Method
Ogawa	PS-124/134	NO2/NOx	Colorimetry for nitrite
Ogawa	PS-144	SO2	Ion chromatography
Radiello	141	HCs C4–C5, CS2	Thermal desorption/GC/MS
Radiello	145	HCs C6–C8	Thermal desorption/GC/MS
Radiello	165	Aldehydes	HPLC/UV

Table 2. VOC source profiles used for CMB receptor modeling

Profile Name	Emission Source Represented	Origin
TANK_VENT	Condensate tank fugitive emissions	Phase 1 of this project
NG	Residential natural gas	1998 Central Texas On-Road Hydrocarbon Study^a
LDGV	Light-duty gasoline vehicle exhaust	NREL/DOE Van Nuys Tunnel Study—Los Angeles, 2010^b
HDD	Heavy-duty diesel exhaust	EC Diesel Study^c
HWY_MIXED	Mixed-fleet highway emissions	Phase 1 of this project
LAWNMWR	Small 2-stroke gas engines	Phase 1 of this project

Notes: ^aCommercial natural gas samples were collected from residential gas lines into 3-L stainless steel canisters. The profile is a composite of two samples from Lone Star Gas Company and Southern Union Gas Company (Fujita, et al., 1999). ^bFujita et al. (2012). ^cLev-On, et al. (2002).

Figure 3. Composition of hydrocarbons in source samples collected during Phase 1. Compounds are divided into two groups: (a) C2–C5 and (b) C6–C10, to show detail. Percentages shown are volumetric.

Figure 4. Composition of carbonyl compounds in source samples collected during Phase 1. Percentages shown are volumetric.

Figure 5. VOC gradient downwind of a well with condensate tank emissions. (a) Aromatics and cycloalkanes (linear scale); (b) aliphatic hydrocarbons (log scale). Concentrations are background subtracted 7-day averages for the week of May 13, 2010.

Figure 6. The concentration gradient downwind of a well with condensate tank emissions. Values are 7-day averages for the week of May 13, 2010 (week 4), normalized to the concentration nearest the well.

Figure 7. Aldehyde gradient downwind of a well with condensate tank emissions. Concentrations are background-subtracted averages.

Table 3. Weekly mean of meteorology parameters from data collected at site PSSV01

	Temperature	Relative Humidity	Wind Speed	Easterly Wind Vector	Northerly Wind Vector
Week	(°C)	(%)	(m/sec)	(m/sec)	(m/sec)	RWD
April 22–April 29	18.0	58.7	1.0	−0.09	−0.34	SSE
April 29–May 6	20.1	61.3	1.1	0.00	−0.68	S
May 6–May 13	22.5	62.9	2.0	0.53	−1.31	SSE
May 13–May 20	21.9	77.9	0.7	0.25	−0.09	ESE

Notes: RWD = resultant wind direction. Negative wind vectors indicate prevailing wind from opposite direction.

Figure 8. Average (a) benzene and (b) n-pentane concentrations at Shale Creek community sites over 21 days, ordered from left to right according to increased distance from the compressor station. PSSV11: W side of compressor station; PSSV09: SE corner of compressor station, PSSSV08: NE of compressor station; PSSV01–PSSV07: residential sites in Shale Creek community; PSSV10: County Line Road; PSSV12: 1 mile S. Corresponding data from TCEQ autoGC sites are included for comparison.

Figure 9. Mean NO and NO₂ concentrations over sampling period. PSSV11: W side of compressor station; PSSV09: SE corner of compressor station, PSSV08: NE of compressor station; PSSV01–PSSV07: residential sites in Shale Creek community; PSSV10: County Line Road; PSSV12: 1 mile S. Sites are ordered according to increased distance from the compressor station. Corresponding data from a monitoring station in Fort Worth are also shown for comparison.

Figure 10. Composition of PM_2.5 mass for all 4 weeks of sampling at Shale Creek sites. Error bars indicate the uncertainty of the gravimetric mass measurement.

Figure 11. Average PAH concentrations at Shale Creek community sites (PSSV01–PSSV06) and Star Shell Road site (PSSV14).

Figure 12. Mean relative source contribution estimates of four source categories to (a) total hydrocarbons, (b) benzene, and (c) pentane for each monitoring site.

Fujita, E.M., R.E. Keislar, J.L. Bowen, W. Goliff, F. Zhang, L.H. Sheetz, M.D. Keith, J.C. Sagebiel, and B. Zielinska. 1999. 1998 Central Texas On-Road Hydrocarbon Study. Final report prepared for the Texas Department of Transportation, Austin, TX.

 Google Scholar

Fujita, E.M., D.E. Campbell, B. Zielinska, J.C. Chow, C.E. Lindhjem, A. DenBleyker, G.A. Bishop, B.G. Schuchmann, D.H. Stedman, and D.R. Lawson. 2012. Comparison of the MOVES2010a, MOBILE6.2, and EMFAC2007 mobile source emission models with on-road traffic tunnel and remote sensing measurements. J. Air Waste Manage. Assoc. 62: 1134–1149. doi:10.1080/10962247.2012.699016

 Web of Science ®Google Scholar

Lev-On, M., C. LeTavec, J. Uihlein, K. Kimura, T.L. Alleman, D.R. Lawson, K. Vertin, M. Gautam, G.J. Thompson, W.S. Wayne, N. Clark, R. Okamoto, P. Rieger, G. Yee, B. Zielinska, J. Sagebiel, S. Chatterjee, and K. Hallstrom. 2002. Speciation of Organic Compounds from the Exhaust of Trucks and Buses: Effect of Fuel and After-Treatment on Vehicle Emission Profiles. Society of Automotive Engineers, I., Paper No. 2002-01-2873. Paper from the Society of Automotive Engineers (SAE) Powertrain and Fluid Systems Conference and Exhibition, October 2002, San Diego, California. Warrendale, PA: Society of Automotive Engineers, Inc.

 Google Scholar