CSG Law Alert: EPA Ratchets Down on Fine Particulate Standards

The United States Environmental Protection Agency (“EPA”) made a significant decision last month regarding public health by changing the rules for the amount of fine particulate matter allowed in the air.

On February 7, 2023, the EPA announced a final action to revise the primary annual National Ambient Air Quality Standard (“NAAQS”) for fine particulate matter, also known as PM2.5, from 12.0 micrograms/cubic meter (µg/m3) to 9.0 µg/m3. The primary NAAQS is the standard set for a criteria pollutant based on public health impacts. According to EPA Administrator Michael Regan, EPA has determined that the current primary PM2.5 NAAQS is no longer sufficient to protect public health. The EPA decided to retain without changes the current primary 24-hour NAAQS for PM10, and the secondary NAAQS for both PM2.5 or PM10. This decision is expected to prompt closer scrutiny of emissions from various sources, potentially leading to changes in industrial practices and a broader conversation about the balance between economic activities and environmental concerns.

NAAQS specify the maximum permissible amount of a pollutant present in outdoor air. Particulate matter (“PM”), contains microscopic solids or liquid droplets that are small enough to be inhaled and cause health problems. PM less than 10 micrometers can be inhaled into the lungs and potentially enter the bloodstream. PM less than 2.5 micrometers in diameter poses the greatest risk to health. EPA has set both primary and secondary NAAQS for both PM10 and PM2.5. PM2.5 principally derives from heavy-manufacturing industries, and power plant and transportation combustion, but can also derive from naturally occurring events such as forest fires.

Not surprisingly, on March 6, 2024, 24 states challenged EPA’s new PM2.5 NAAQS. In addition, several national industry groups, led by the United States Chamber of Commerce, along with the American Chemistry Council, the American Forest & Paper Association, the American Petroleum Institute, the American Wood Council, the National Association of Manufacturers, the National Mining Association, and the Portland Cement Association, filed petitions challenging the NAAQS. Both challenges were filed in the United States Court of Appeals for the District of Columbia Circuit.

Pursuant to the Federal Clean Air Act, states now have the responsibility to designate areas within the state that either meet the standard (attainment areas) or do not meet the standard (non-attainment areas). These designations will be based on the most recent set of air monitoring or modeling characterizing each area. EPA has two years after promulgation of a new standard to finalize designations, with a possible one-year extension. States will then have to develop State Implementation Plans to maintain the new PM2.5 NAAQS and a specific plan to attain the standard in those areas designated as non-attainment.

Although the final NAAQS designation for PM2.5 is the first step of a multi-year process, it is significant in that it may increase the difficulty of new industrial or power generating facilities, or those facilities that would like to expand operations, in obtaining air permits for those facilities that may increase emissions of PM2.5. For example, in New Jersey, facilities that have the potential to emit more than 100 tons per year of PM2.5 (or 100 tons per year of SO2 or NOx which are PM2.5 precursors), may have to obtain creditable emission reductions, typically through additional control technologies, curtailment of operations, or purchasing banked emission reductions from other facilities that have such emission reductions. Control technologies and curtailment add significant expense and banked emission reductions have become very difficult to obtain in recent years. The final PM2.5 designations in New Jersey will be critical in determining whether obtaining permits will become more difficult for new facilities, or facilities expanding operations.

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