New Optical Gas-Imaging Technology for Quantifying Fugitive-Emission Rates

The U.S. Environmental Protection Agency (EPA) has promulgated regulations governing the detection and repair of equipment leaks that cause fugitive emissions of volatile organic compounds (VOC). These regulations are embedded in various emission standards and are generally referred to as Leak Detection and Repair (LDAR) programs. The primary method used currently in the U.S. to detect leaks is EPA Method 21.1 Method 21 requires operators to use portable instruments, typically a Flame Ionization Detector (FID) or a Photon Ionization Detector (PID), to "sniff" around the circumference of individual equipment components (e.g., valves, flanges, pump seals, etc.)2. If the detector reading (parts per million or PPM) is higher than target thresholds, the component is deemed to be leaking and it must be repaired within a certain time. Fugitive VOC emissions from a facility are calculated based upon the PPM readings (referred to as screening values or SVs) and empirical correlations between SVs and mass emission rates.2 Because the leak check is performed on each individual component basis, the implementation of a Method 21 based LDAR program is tedious, labor intensive, and prone to errors. Optical gas imaging (OGI) technology has been developed and can be used to detect VOC leaks from process equipment. The OGI technology allows operators to use a specially designed Infrared (IR) video camera to see VOC plumes leaking from components that are not visible to the naked eye. Detecting VOC leaks using OGI is more efficient than Method 21 because leak checking using OGI is visual, making detection faster, and can be performed over an area instead of component-by-component. The OGI method allows operators to detect larger leaks easily and more frequently, achieving the same environmental benefit with a lower cost. For this reason, the OGI method is also referred to as "Smart LDAR". In December 2008, U.S. EPA promulgated the "Alternative Work Practice" (AWP) rule allowing operators to use OGI for LDAR compliance.3 However, the AWP rule requires operators to continue to perform leak checks using Method 21 at least once a year. Although OGI can be very effective in detecting leaks, it does not provide a quantitative measure of leak rate. This has been one of the shortcomings of OGI from a regulatory perspective, thereby hindering its adoption as a true alternative to Method 21. This paper describes development of quantitative OGI (QOGI) technology. Existing OGI camera technology is the basis the new GOCI technology. If an OGI camera detects a leak, then, the operator can apply the new QOGI technology quantify the mass leak rate from the captured video images.

Aquatic herbicides are commonly used to control a wide variety of algae and plants, but they also have the potential to contaminate and affect nontarget organisms. However, the impacts of low-level 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide exposure on larval fish are not well understood. We conducted a series of experiments to determine the effects of low concentrations (0.05, 0.50, and 2.00 ppm) of 2 commercial 2,4-D amine salt herbicide formulations (Weedestroy® AM40 [WAM40] and DMA® 4 IVM [DMA4]) and pure 2,4-D on the development and survival of fathead minnows (Pimephales promelas) at various life cycle stages. Larval survival (30 d post hatch [dph]) was decreased following exposure of eggs and larvae to pure 2,4-D (0.50 ppm; p ≤ 0.001), as well as to WAM40 (0.50 and 2.00 ppm; p ≤ 0.001, p ≤ 0.001) and DMA4 (0.50 and 2.00 ppm; p ≤ 0.001, p ≤ 0.001). The results also narrowed the critical window of exposure for effects on survival to the period between fertilization and 14 dph. Development was not negatively altered by any of the compounds tested, although the commercial formulations increased larval total length and mass at 2.00 ppm. Altogether, the results indicate that the use of 2,4-D herbicides for weed control in aquatic ecosystems at current recommended concentrations (<2 ppm whole lake; <4 ppm spot treatment) could present risks to fathead minnow larval survival. Environ Toxicol Chem 2018;37:2550–2559. © 2018 SETAC

Methane (CH 4 ) is the dominant constituent of natural gas and plays a significant role in climate change as a powerful greenhouse gas. CH 4 lingers 30 times more than CO 2 in the atmosphere and has a greater potency in trapping heat. Human activities such as Oil and Gas production, underground mining, and landfill activities contribute to 25% to 33% of global warming worldwide. Traditional methods often lack real-time and accurate monitoring capabilities. To reduce the effect of methane emissions on global warming, several research works have demonstrated the efficiency of Passive Infrared Optical Gas Imaging in methane detection and quantification, which is widely used in Leak Detection and Repair programs (LDAR) as a non-destructive and non-invasive method. The combination of Machine Learning procedures such as Faster Region Convolutional Neural Network (Faster R-CNN) along with thermal infrared cameras was proven to be effective for methane detection and quantification. However, challenges remain in accurately determining emission rates. Recent studies have also revealed that methane emissions estimates provided by agencies like the Environmental Protection Agency (EPA) are often significantly underestimated. Recently, several detection projects demonstrated that the estimates the Environment Protection Agency (EPA) provided are underestimated. This paper explores the integration of machine learning models with optical gas imaging, examining methodologies, results, and limitations in methane detection across the petroleum industry, underground mining, and landfill sectors. Future research directions include improving detection algorithms to enhance accuracy under varying environmental conditions, developing lower-cost sensor technologies for widespread deployment, and addressing regulatory challenges to ensure consistent and reliable methane reporting practices. This addition outlines promising future research areas and emphasizes key technical and regulatory challenges that must be addressed to advance methane monitoring capabilities. Keywords: Greenhouse gas emissions, methane detection and quantification, Optical Gas Imaging, Infrared Technology, Faster R-CNN. DOI : 10.7176/JETP/14-3-05 Publication date : October 30th 2024

Most volatile organic compounds are considered potentially harmful air pollutants to the environment and most importantly human health. The present work investigated the concentrations of 72 volatile organic compounds commonly emitted from the vehicular exhausts at a hospital parking garage. The objective was set to assess the associated health risk due to inhalation of these compounds during weekdays versus weekends. Carcinogenic and non-carcinogenic health risks were assessed using the US Environmental Protection Agency conventional approach. A total of 112 air samples were collected inside the hospital parking garage using six-liter evacuated Silonite™-coated polished stainless steel canisters. Triplicate sampling was used for quality assurance/quality control purposes. The air samples were analyzed using the gas chromatography with flame ionization detection system, which followed the US Environmental Protection Agency TO-15 Method. The overall 24-h concentrations of benzene, toluene, ethylbenzene, and xylenes were 6.78, 31.14, 11.35, and 27.85 μg/m3, respectively. These values were comparable to values reported in Europe, North America, and Asia. The weekend concentrations were lower than the weekday ones. Halogenated compounds had the highest contribution of volatile organic compounds groups to total concentrations in both weekday and weekend. The weekday and weekend concentrations temporal cycles were characterized, and they were correlated with the traffic activity inside the parking garage. Two of the measured compounds (i.e., tetrachloromethane and 1,2-dibromoethane) were discovered to pose definite cancer risk. To our knowledge, this is the first study in the region which looks at volatile organic compound levels in a parking garage and the associated health risks.

<p>The Danish voluntary methane monitoring programme for agricultural biogas producing facilities was launched by the Danish Biogas Association in autumn, 2016. The Danish Biogas Association had set a san overall goal of reducing the total methane loss from Danish biogas and upgrading plants on a national level to less than 1% of production by 2020.</p><p>The Danish Government has allocated approximately 1.3 million € to monitor and reduce methane emissions from the biogas sector in the period 2019-2020, based on previous experiences. The funds are used to administer this new programme, method testing, validation of measurement service providers and to provide partial funding for the participation of biogas plants. Also, the project includes recommendations to the Danish Energy Agency regarding use of measurements in regulation based on the results of the programme. The programme includes agricultural biogas plants (both farm-scale and centralized plants), industrial biogas plants and biogas plants treating sludge from wastewater treatment. The biogas plants provide partial funding. Three levels of own-funding are used depending on the magnitude of gas production. Large biogas plants pay a larger fraction of expenses than smaller plants. This was chosen to ensure participation of smaller facilities.</p><p>At each biogas plant, two or more of the following actions are performed:</p><p>1. Initial agreement on services and expectations</p><p>2. Development of self-monitoring programme</p><p>3. Leakage search and mitigation recommendations</p><p>4. Quantification of methane loss using remote sensing</p><p>5. Draft project of emission reduction initiatives</p><p>Actions 1 and 4 are mandatory for the participating biogas plants. The leakage search (Action 3) is performed using Optical Gas Imaging (OGI). Here, a measurement technician uses OGI to identify leakages both outdoors on tanks, pipes etc., and indoors. The report lists and illustrates leakages (through video documentation) and provides advise on mitigation actions were applicable. Even though OGI is not used quantitatively, the leaks are categorized as low, medium and high emission rates based on the operator’s assessment from the OGI videos.</p><p>Quantification of the biogas plants total methane emission (Action 4) is done using a tracer gas dispersion method. This remote sensing method includes the controlled, continuous release of a tracer gas (C<sub>2</sub>H<sub>2</sub> in this case) combined with downwind, cross-plume measurements of methane and tracer gas. This method is described in Scheutz and Fredenslund (2019). It has been used to quantify emissions from biogas plants in the previous voluntary programme as well as to measure fugitive emissions from other area sources such as landfills, composting facilities and wastewater treatment plants.</p><p>About 60 plants have signed up and measurement and consultation activities are currently ongoing. The plants include about 35 manure-based biogas plants, 2 industrial biogas plants and 22 wastewater treatment plants. All activities are to be completed by the end of February, 2021.</p><p>This presentation will include a short introduction to the programme, observed emission rates and emission factors, typical sources of methane emission, mitigation options, recommendations regarding regulation and economic factors such as expenses for the monitoring activities.</p><p><strong>Reference</strong></p><p>Scheutz, C., Fredenslund, A.M. 2019. Total methane emission rates and losses from 23 biogas plants. Waste Management, 97, 38-46.</p>

Hydrocarbon leaks in large scale LNG and gas processing and handling facilities present a risk to health and safety, as well as a negative impact on the environment. Existing autonomous leak detection systems rely primarily on point and path detection. This technology requires dispersed gas to physically contact the point sensors or move between two path detectors. Manual leak checks are also performed periodically by checking one component at a time using a flame ionization detector (FID) or optical gas imager, however the size and complexity of these facilities means that smaller leaks may go undetected for extended periods of time and unintended releases may occur when plant personnel are not present. ExxonMobil Research Qatar Ltd. and Providence Photonics LLC have developed the IntelliRed™ Remote Gas Detection system that integrates computer vision algorithms and infrared (IR) optical gas imaging technology to autonomously scan for and identify leaks. The IntelliRed™ system utilizes a unique mid-wave IR (MWIR) imager and a computer vision algorithm that analyzes the video output from the IR imager to determine the presence of hydrocarbon plumes. Most hydrocarbons have strong absorbance peaks in a narrow MWIR region. The algorithm takes advantage of the difference in contrast between a hydrocarbon plume and the background in an IR imager. The algorithm compares sequentially collected IR images and uses a multi-stage confirmation process to model the behavior of the plume and confirm the detection. It has multiple filters that mitigate interferences such as humans, vehicles, and trees. After extended pilot deployments, the IntelliRed™ technology has been qualified and is commercially available for leak detection and environmental applications. An innovative differential infrared (DIR) camera design now offers the possibility of lower detection limits and higher immunity to false alarms for the IntelliRed™ system. The design employs two cooled MWIR sensors with a common optical path. The infrared energy from the scene is divided using a beam splitter, focusing a spatially registered image on each sensor. The spectral filtering for the two sensors is chosen so that one sensor can visualize a hydrocarbon plume while the second sensor cannot. A synchronized system clock for the two sensors ensures that the frames are temporally aligned. The result is a camera which produces both spatially and temporally aligned frames with the plume present in one frame but absent in the other. A differential image is produced by comparing the two sensors frame by frame, providing a robust filter for common interferences such as steam and dust plumes. The DIR camera design requires new computer vision techniques to exploit the information provided by the reference sensor. Results are compared to other autonomous hydrocarbon detection technologies, including single sensor IntelliRed™ technology. New applications enabled by the DIR camera design are discussed, including aerial pipeline surveys. The technology is currently being qualified with DIR based IntelliRed™ pilot deployments underway in Qatar and the United States.

This monitoring plan provides the information necessary to perform routine organic air emissions monitoring at the Waste Storage Facilities located at the Transuranic Storage Area of the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory. The Waste Storage Facilities include both the Type I and II Waste Storage Modules. The plan implements a dual method approach where two dissimilar analytical methodologies, Open-Path Fourier Transform Infrared Spectroscopy (OP-FTIR) and ancillary SUMMA{reg_sign} canister sampling, following the US Environmental Protection Agency (EPA) analytical method TO-14, will be used to provide qualitative and quantitative volatile organic concentration data. The Open-Path Fourier Transform Infrared Spectroscopy will provide in situ, real time monitoring of volatile organic compound concentrations in the ambient air of the Waste Storage Facilities. To supplement the OP-FTIR data, air samples will be collected using SUMMA{reg_sign}, passivated, stainless steel canisters, following the EPA Method TO-14. These samples will be analyzed for volatile organic compounds with gas chromatograph/mass spectrometry analysis. The sampling strategy, procedures, and schedules are included in this monitoring plan. The development of this monitoring plan is driven by regulatory compliance to the Resource Conservation and Recovery Act, State of Idaho Toxic Air Pollutant increments, Occupational Safety and Health Administration. The various state and federal regulations address the characterization of the volatile organic compounds and the resultant ambient air emissions that may originate from facilities involved in industrial production and/or waste management activities.

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The US Environmental Protection Agency (EPA) estimates on-road vehicles emissions using the Motor Vehicle Emission Simulator (MOVES). We developed updated ammonia emission rates for MOVES based on road-side exhaust emission measurements of light-duty gasoline and heavy-duty diesel vehicles. The resulting nationwide on-road vehicle ammonia emissions are 1.8, 2.1, 1.8, and 1.6 times higher than the MOVES3 estimates for calendar years 2010, 2017, 2024, and 2035, respectively, primarily due to an increase in light-duty gasoline vehicle NH3 emission rates. We conducted an air quality simulation using the Community Multi-Scale Air Quality (CMAQv5.3.2) model to evaluate the sensitivity of modeled ammonia and fine particulate matter (PM2.5) concentrations in calendar year 2017 using the updated on-road vehicle ammonia emissions. The average monthly urban ammonia ambient concentrations increased by up to 2.3 ppbv in January and 3.0 ppbv in July. The updated on-road NH3 emission rates resulted in better agreement of modeled ammonia concentrations with 2017 annual average ambient ammonia measurements, reducing model bias by 5.8 % in the Northeast region. Modeled average winter PM2.5 concentrations increased in urban areas, including enhancements of up to 0.5 μg/m3 in the northeast United States. The updated ammonia emission rates have been incorporated in MOVES4 and will be used in future versions of the NEI and EPA's modeling platforms.

Received for publication September 11, 2000, and accepted for publication September 10, 2001. Abbreviations: CDC, US Centers for Disease Control and Prevention; EPA, US Environmental Protection Agency; FDA, US Food and Drug Administration; NRC, National Research Council. From the US Environmental Protection Agency, Washington, DC. Correspondence to Dr. Lynn Goldman, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Suite W8511, Baltimore, MD 21205 (e-mail: lgoldman@jhsph.edu). While epidemiologic evidence and, particularly, results of individual studies is often highly controversial, epidemiologic findings often play a significant role in the development of many environmental standards and regulations. This prominence reflects the direct relevance of epidemiologic evidence to public health, which was a focus for new policy initiatives over the first 5 years of the Clinton administration. Federal environmental statutes state that protection of human health is a major goal in ensuring, for example, clean water, clean air, and responsible management of waste. At times in the past, however, there was less focus on public health and greater reliance on projections of theoretical tools, such as modeling and risk assessment as the basis for selecting among policy options. With the implementation of the Government Performance and Results Act of 1993 (1), a government-wide effort began to identify ways for measuring and tracking outcomes of governmental efforts, including those of the US Environmental Protection Agency (EPA) and other regulatory agencies. At the same time, there is increased appreciation of the relevance of epidemiology in the public policy arena (2). A demand for more surveillance and other epidemiologic data can be anticipated. There are numerous other forces that have pushed regulatory agencies in the direction of relying more on epidemiology. Industry has questioned the applicability of animal toxicology data to human health risk and has wanted human data to be used to validate this practice. Public health advocates have pushed regulatory agencies to look beyond cancer and other diseases that are more readily assessed using animal models to include other diseases (e.g., reproductive, neurologic, and respiratory) where epidemiology studies have indicated there may be additional risks. The National Toxicology Program has recently begun to incorporate more epidemiology information into its cancer assessments for the Report on Carcinogens. Epidemiologists and the findings of epidemiologic studies will probably play a more significant role in environmental regulation in the future. This presentation offers the perspective of a physicianepidemiologist on the role of epidemiologic evidence in the regulatory arena. It draws on selected examples and experiences of the author as a basis for general considerations on epidemiology and regulation. While the presentation is thus based around a particular era of one administration, it offers more general lessons concerning epidemiology and policy. It is hoped that these perspectives will help to promote a greater understanding of the policy process among epidemiologists, and how their data are likely to be used (and misused). It is also hoped to promote a greater understanding and appreciation of the need to incorporate epidemiology among risk assessors (who predominantly are toxicologists).

To evaluate the possible impact that the BP Deepwater Horizon Gulf oil spill might have had on pollution levels in the State of Mississippi, the Mississippi Department of Environmental Quality (MDEQ), and the US Environmental Protection Agency (EPA) analyzed surface water and ambient air quality pollutant data taken from MDEQ and EPA monitoring sites on the Mississippi Gulf Coast. The data were compared with acute, chronic, and human health air and water quality standards to determine whether the pollutant levels occurring during the oil spill could cause ecological and/or human health effects. The water quality data indicated levels of nickel, vanadium, volatile organic compounds (VOCs), and semivolatile organic compounds analyzed remained below acute and chronic levels for both aquatic life and human health. The air quality sampling data showed that the levels of VOCs and polycyclic aromatic hydrocarbons associated with the oil spill were well below EPA chronic and human health screening levels. A comparison of the air quality monitoring data taken before and after the oil spill showed that the concentrations of ozone and fine particulate matter were elevated for brief periods but remained below actionable levels.

Development and validation of a method for air-quality and nuisance odors monitoring of volatile organic compounds using multi-sorbent adsorption and gas chromatography/mass spectrometry thermal desorption system

In this study, a leak detection and repair program was conducted on five pharmaceutical factories in China to analyze the volatile organic compounds (VOCs) emission characteristics of leaking equipment. The results indicated that the monitored components were mainly flanges, accounting for 70.23% of the total, and open-ended lines were the components most prone to leaks. The overall percentage of VOCs emissions reduction after the repair was 20.50%, and flanges were the most repairable components, with an average emission reduction of 47.5 kg/a for each flange. In addition, atmospheric predictions were conducted for the VOCs emissions before and after the repair of the components at the research factories. The atmospheric predictions showed that emissions from equipment and facilities have a noticeable impact on VOCs concentration at boundary and the emissions are positively correlated with the pollution source strength. The hazard quotient of the investigated factories was lower than the acceptable risk level set by the US Environmental Protection Agency (EPA). The quantitative assessment of the lifetime cancer risk showed that the risk levels of factories A, C, and D exceeded the EPA’s acceptable risk level, and the on-site workers were exposed to inhalation cancer risk.

Ozone in the urban atmosphere can accumulate from photochemistry involving nitrogen oxides, carbon monoxide, and volatile organic compounds mainly emitted from fossil fuel combustions and volatile chemical products. Concentrated ozone near the earth's surface has a detrimental impact on the ecosystem and our health. The Los Angeles Basin is a classic example of an urban region with long‐standing ozone pollution, frequently in violation of its standard, designated by the US Environmental Protection Agency (EPA). Studies have reported substantial declines of ozone and their precursor concentrations over the past half century in this area due to extensive pollution controls. Since 2000, however, the ozone design value has remained the same and has not been able to fully reach the air quality standard set by the EPA despite decreases in its precursor concentrations. To understand this phenomenon, we utilize a chemical transport modeling approach to reproduce historical ozone trends and to conduct sensitivity runs relative to a 2010 baseline. Based on our analysis of the model simulations comparing the weekends and weekdays, rather than focusing only on the weekly averages, we diagnose that the Los Angeles Basin is actually going under a significant transition in photochemistry toward a lower ozone concentration. This reveals how air quality management strategies are slowly moving towards a pathway of reducing ozone concentrations in the future. Our study, however, suggests that further reductions of NOx emissions can lead to continued improvement of ozone pollution in this area.

Volatile organic compounds (VOCs) are deƒned as organic compounds that evaporate readily at room temperature, such as benzene, toluene, ethylbenzene, and xylenes (BTEX) and chlorinated solvents such as trichloroethylene (U.S. Environmental Protection Agency [USEPA], 2011). VOCs are easily absorbed and broadly metabolized in the human body (Agency for Toxic Substances and Diseases Registry [ATSDR], 2004). The U.S. Environmental Protection Agency (USEPA) has speciƒed a number of VOCs as air toxics. In many urban areas of Asia, several anthropogenic sources, such as trafƒc, residential, and industry, release large amounts of VOCs into the atmosphere, which subsequently build up to high ambient levels. In the atmosphere with the presence of sunlight, VOCs participate in photochemical reactions with NOx (nitrogen oxides) to form photochemical smog. High levels of ƒne particles and surface ozone present in the smog are health hazards. Ozone is a strong greenhouse gas and a phytotoxic pollutant that damages plants and affects agriculture and forestry, as highlighted in Chapter 6.