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DOI:10.3155/1047-3289.61.8.834 ABSTRACT In 2009, the U.S. Environmental Protection Agency (EPA) executed a year-long field study at a refinery in Corpus Christi, TX, to evaluate the use of passive diffusive sampling [...]

In 2006, the U.S. Environmental Protection Agency posted a new test method on its website called Other Test Method 10 (OTM 10) which describes direct measurement of pollutant mass emission flux from area sources using ground-based optical remote sensing. The method has validated application to relatively small bounded area sources but additional guidance is needed for large area sources, such as landfills, where the emission zone can exceed the size of optical configuration leading to difficulties in relating measured fluxes to emissions per unit area. This paper presents the findings of a series of tracer-release experiments designed to improve the understanding of OTM 10 in landfill applications. OTM 10 plume capture efficiency data acquired at a variety of landfill sites under a range of meteorological conditions and measurement configurations are presented. Experiments indicate an overall capture efficiency factor of 0.81 with a standard deviation of 0.33. Lower capture efficiencies from side slope releases are noted (0.69). The combined data set is analyzed for factors influencing capture efficiency. A multiple linear regression is used to model the capture efficiency as a function of primary parameters including distance of the tracer release from the observing plane and wind speed. A simplified model based on the regression analysis is described and its use for approximating the area contributing to flux is presented. DOI: 10.1061/(ASCE)EE.1943-7870.0000157 CE Database subject headings: Landfills; Methane; Emissions; Remote sensing; Environmental Protection Agency; Internet. Author keywords: Landfill; Methane; Fugitive emission; Optical remote sensing; EPA OTM 10; Area source; Tunable diode laser.

ABSTRACT There is a need for robust and accurate techniques for the measurement of ammonia ([NH.sub.3]) and other atmospheric pollutant emissions from poultry production facilities. Reasonable estimates of [NH.sub.3] emission [...]

ABSTRACT Assessment of near-road air quality is challenging in urban environments that have roadside structures, elevated road sections, or depressed roads that may impact the dispersion of traffic emissions. Vehicles [...]

ABSTRACT Understanding motor vehicle emissions, near-roadway pollutant dispersion, and their potential impact to near-roadway populations is an area of growing environmental interest. As part of ongoing U.S. Environmental Protection Agency [...]

ABSTRACT Air pollutant emission from unconfined sources is an increasingly important environmental issue. The U.S. Environmental Protection Agency (EPA) has developed a ground-based optical remote-sensing method that enables direct measurement [...]

A pilot study was conducted in application of the U.S. Environmental Protection Agency (EPA) Methods 325A/B variant for monitoring volatile organic compounds (VOCs) near two oil and natural gas (ONG) production well pads in the Texas Barnett Shale formation and Colorado Denver–Julesburg Basin (DJB), along with a traffic-dominated site in downtown Denver, CO. As indicated in the EPA method, VOC concentrations were measured for 14-day sampling periods using passive-diffusive tube samplers with Carbopack X sorbent at fenceline perimeter and other locations. VOCs were significantly higher at the DJB well pad versus the Barnett well pad and were likely due to higher production levels at the DJB well pad during the study. Benzene and toluene were significantly higher at the DJB well pad versus downtown Denver. Except for perchloroethylene, VOCs measured at passive sampler locations (PSs) along the perimeter of the Barnett well pad were significantly higher than PSs farther away. At the DJB well pad, most VOC concentrations, except perchloroethylene, were significantly higher prior to operational changes than after these changes were made. Though limited, the results suggest passive samplers are precise (duplicate precision usually ≤10%) and that they can be useful to assess spatial gradients and operational conditions at well pad locations over time-integrated periods. Implications: Recently enacted EPA Methods 325A/B use passive-diffusive tube samplers to measure benzene at multiple fenceline locations at petrochemical refineries. This pilot study presents initial data demonstrating the utility of Methods 325A/B for monitoring at ONG facilities. Measurements revealed elevated concentrations reflective of production levels and spatial gradients of VOCs relative to source proximity at the Barnett well pad, as well as operational changes at the DJB well pad. Though limited, these findings indicate that Methods 325A/B can be useful in application to characterize VOCs at well pad boundaries. [ABSTRACT FROM PUBLISHER]