Air Quality Monitoring

While annual reports on emission levels are required to be filed with the DEP, CNX has committed to strongly enhance our program and initiate air quality monitoring around our well pads and compressor stations to provide timely and relatable data through a dashboard on a publicly available website.

Our program will end the speculation that is caused by lack of transparency and uncertainty, and replace it with measured data that dispels any misconception that we are not operating within acceptable standards. CNX began with the NV110 producing well pad and has expanded the enhanced monitoring program to incorporate compressor stations and well pads in the construction, drilling, and completions phases of development through approximately 6 months of production, i.e. once the gas well begins producing gas and significant activity at the site ends. Monitoring includes continuous monitoring of particulate matter measuring less than 2.5 microns in diameter (PM2.5) and Benzene, Toluene, Ethylbenzene, and Xylene, collectively referred to as BTEX compounds. PM2.5 is produced by diesel exhausts, smoke from fires and various other everyday sources such as unpaved roadways and farm fields.

All data is collected by and reviewed for quality assurance by Clean Air Engineering, whose activities are governed by their Ambient Monitoring Quality Management Plan (QMP), which details their quality control program for ambient air quality monitoring services. The QMP was audited by the United States Environmental Protection Agency (EPA) in 2017, and the company was approved for the operation of State and Local Air Monitoring Stations (SLAMS) as a Primary Quality Assurance Organization. All data is provided unabridged directly to the Pennsylvania Department of Environmental Protection (DEP) and to CNX Resources.


CNX is measuring concentrations of particulate matter smaller than 2.5 microns in diameter (PM2.5) following the strict methodology established by the Environmental Protection Agency (EPA) by installing two air quality monitoring devices, one upwind and another downwind of each well pad. PM2.5 data is presented in hourly and 24-hour average concentrations via a dashboard on this website. The project data is compared to data reported by the regional air quality monitoring network maintained by the DEP and compared to the National Ambient Air Quality Standards.

To complement the data generated by each PM2.5 monitor, each site includes an integrated meteorological measurement system to record wind speed and wind direction via a compact sonic anemometer. Wind and other meteorological data are recorded on a local data logger and transmitted to Clean Air Engineering’s secure environmental data management platform for easy access and visualization.


Natural gas may contain low levels of various volatile organic compounds (VOC), including BTEX. To demonstrate our low VOC levels, CNX is incorporating EPA Reference Method 325 that has been established to measure VOC in air by exposing sample tubes to air for a period of 14-days. CNX analyzes the samples for BTEX compounds, which are absorbed by the material within the sampling tube. Results are compared to established health-based standards such as Minimum Risk Levels (MRLs) for inhalation exposure. Should any elevated levels of BTEX be encountered, CNX will conduct verification sampling using the EPA TO-15 methodology to review a larger suite of compounds.

Methane Monitoring

CNX has incorporated an intensive monitoring and improvement program to reduce our overall methane emissions that parallels our efforts to reduce emissions of PM2.5 and BTEX, and we believe a detailed understanding of the effectiveness of our methane emission reduction efforts provides us with confirmation of the success and efficiency our program to reduce emissions overall.

CNX exceeds state and federal requirements for leak detection at our facilities on average, performing more than 100,000 direct monitoring observations using optical gas imaging cameras at 220 facilities every calendar quarter. We supplement these inspections with quarterly satellite and fixed-wing-based methane observations of our area of operation. Additionally, we have issued our operators with handheld methane monitors, which they use to confirm the absence of methane leaks as part of their daily routine maintenance activities and verify the success of leak repair.

Our low methane emissions are not surprising, given our 2023 investment of $7 million in emission reduction efforts. Our efforts included replacing or modifying nearly 1,000 pneumatic devices to zero-emission operation, changing our well-bore liquids unloading processes, and incorporating other operational best practices, which have reduced our CO2e tons of methane by an additional 70,000 tons during 2023. Our methane intensity is a very low 0.04% for our production segment and 0.02% for our midstream segment.


The data displayed in the CNX transparency tool is collected, recorded, and provided by a third party indicated as the data source and not by CNX. For many or all of the data, the data is by its nature considered a field estimate and as initially recorded may contain errors introduced by equipment malfunction or other inaccuracies introduced by the data provider(s). The data as initially posted is subject to review and quality assurance and control conducted by the third party and may be corrected or otherwise edited or deemed null according to standard quality assurance/control procedures.

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