scholarly journals Air quality measurements in the western Eagle Ford Shale

Elem Sci Anth ◽  
2020 ◽  
Vol 8 ◽  
Author(s):  
Geoffrey S. Roest ◽  
Gunnar W. Schade
Keyword(s):  
Air Quality ◽  
Oil And Gas ◽  
Ambient Air ◽  
Trace Gas ◽  
Ambient Air Quality ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Mixing Ratios ◽  
Trace Gas Emissions ◽  
The Us

The Eagle Ford Shale in southern Texas remains one of the most productive oil and gas regions in the US. Like the Permian Basin and Bakken Shale, ubiquitous natural gas flaring serves as an uncertain source of trace gas emissions within the Eagle Ford. A lack of ambient air quality data, especially in the western shale, impedes a thorough understanding of trace gas emissions within the shale and the subsequent local/regional air quality impacts. Meteorological and trace gas instrumentation was deployed to Shape Ranch in southwestern Dimmit County, near the US/Mexico border, from April to November of 2015. Mixing ratios of CO, NOx, O3, and VOCs did not exceed ambient air quality standards and were generally lower than mixing ratios measured in US cities, with the exception of alkanes. A non-negative matrix factorization demonstrated the dominance of oil and gas-sector emission sources in local trace gas variability, with combustion processes and transport of continental air also present. An analysis of NOx/CO and NOx/CO2 ratios during periods of O3 titration, identified by the ambient NOx/O3 ratio, suggested that combustion and biospheric sources contributed to emissions of NOx, CO, and CO2. In-plume NOx/CO2 ratios indicated relatively low-temperature combustion sources, with median NOx/CO2 ratios close to that expected for natural gas flaring (0.54 ppb/ppm), and much lower than emission ratios for internal combustion engines (>10 ppb/ppm). However, the NOx/CO2 ratio within these plumes exhibited a large variability, spanning more than an order of magnitude. Future research should focus on improving flaring emission factors and flaring volume estimates such that their air quality impacts can be better understood.

Potential Impacts of Integrated Oil and Gas Plant on Ambient Air Quality

2009 ◽  
Vol 20 (3) ◽  
pp. 331-344 ◽  
Author(s):  
Jacob Ademola Sonibare ◽  
Precious Nwobidi Ede
Keyword(s):  
Air Quality ◽  
Oil And Gas ◽  
Ambient Air ◽  
Ambient Air Quality

scholarly journals Changes in summertime ozone in Colorado during 2000–2015

Elem Sci Anth ◽  
2018 ◽  
Vol 6 ◽  
Author(s):  
Tanja Bien ◽  
Detlev Helmig
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Oil And Gas ◽  
Ambient Air ◽  
Quality Standard ◽  
P Value ◽  
Nox Emissions ◽  
Mixing Ratios ◽  
June July ◽  
Surface O3

In 2016, the Denver Metro Area (DMA)/Northern Colorado Front Range (NCFR) was reclassified from a Marginal to a Moderate O3 Non-Attainment Area due to the prevalence of high summer ozone (O3) occurrences. Hourly surface O3 data collected during 2000–2015 from a total of 80 monitoring sites in the State of Colorado were investigated for geographical features in O3 behavior and O3 changes over time. We particularly focus on summer O3 (June, July, August), which is the time when most exceedances of the O3 National Ambient Air Quality Standard (NAAQS) have been recorded. Variables investigated include the statistical (5th, 50th (median), and 95th percentile) distribution of O3 mixing ratios, diurnal amplitudes, and their trends. Trend analyses were conducted for 20 site records that had at least ten years of data. The majority of Colorado ozone monitoring sites show an increase of the 5th (16 total; 11 of these are statistically significant (p-value ≤ 0.05) trends) and 50th (15 total; 4 statistically significant trends) percentile values. Changes for the 95th percentile values were smaller and less consistent. One site showed a statistically significant declining trend, and one site an increasing trend; the majority of other sites had slightly negative, albeit not statistically significant declining O3. Ozone changes at the two highest elevations sites (>2500 m asl) are all negative, contrasting increasing O3 at U.S. West Coast sites. NCFR urban sites do not show the rate of decreasing higher percentile O3 as seen for the majority of urban areas across the U.S. during the past 1–2 decades. The amplitudes of diurnal O3 cycles were studied as a proxy for nitrogen oxides (NOx) emissions and the diurnal O3 production chemistry. The majority of sites show a decrease in the median summer O3 diurnal amplitude (19 total/10 statistically significant). This is mostly driven by the increase in nighttime O3 minima, which is most likely a sign for a declining rate of nighttime O3 loss from titration with nitric oxide (NO), indicating a change in O3 behavior from declining NOx emissions. Since median and upper percentile surface O3 values in the DMA have not declined at the rates seen in other western U.S. regions, thus far the reduction in NOx has had a more pronounced effect on the lower percentile O3 distribution than on high O3 occurrences that primarily determine air quality. An assessment of the influence of oil and gas emissions on Colorado, and in particular DMA O3, is hampered by the sparsity of monitoring within oil and gas basins. Continuous, long-term, high quality, and co-located O3, NOx, and VOC monitoring are recommended for elucidating the geographical heterogeneity of O3 precursors, their changing emissions, and for evaluation of the effectiveness of O3 air quality regulations.

Application of Electron Optics to Characterization of Particulate Pollutants

1972 ◽  
Vol 30 ◽  
pp. 364-365
Author(s):  
J. B. Moran ◽  
J. L. Miller
Keyword(s):  
Air Quality ◽  
Quality Standards ◽  
Ambient Air ◽  
Hazardous Substances ◽  
Fuel Additives ◽  
Ambient Air Quality ◽  
Air Quality Standards ◽  
Emission Standards ◽  
Stationary Sources ◽  
Ambient Air Quality Standards

The Clean Air Act Amendments of 1970 provide the basis for a dramatic change in Federal air quality programs. The Act establishes new standards for motor vehicles and requires EPA to establish national ambient air quality standards, standards of performance for new stationary sources of pollution, and standards for stationary sources emitting hazardous substances. Further, it establishes procedures which allow states to set emission standards for existing sources in order to achieve national ambient air quality standards. The Act also permits the Administrator of EPA to register fuels and fuel additives and to regulate the use of motor vehicle fuels or fuel additives which pose a hazard to public health or welfare.National air quality standards for particulate matter have been established. Asbestos, mercury, and beryllium have been designated as hazardous air pollutants for which Federal emission standards have been proposed.

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