In 2010, the U.S. Environmental Protection Agency (EPA) adopted a 1-hour nitrogen dioxide (NO2) National Ambient Air Quality Standard (NAAQS) of 100 parts per billion (ppb) or approximately 188 micrograms per cubic meter (µg/m3) that is considerably more stringent than the longstanding annual standard of 53 ppb (100 µg/m3). New or modified compressor units may be encumbered by federal or state regulatory requirements to demonstrate compliance with the NO2 NAAQS using AERMOD, EPA’s dispersion model, because the new NAAQS greatly reduces the compliance margin. AERMOD...
In 2010, the U.S. Environmental Protection Agency (EPA) adopted a 1-hour nitrogen dioxide (NO2) National Ambient Air Quality Standard (NAAQS) of 100 parts per billion (ppb) or approximately 188 micrograms per cubic meter (µg/m3) that is considerably more stringent than the longstanding annual standard of 53 ppb (100 µg/m3). New or modified compressor units may be encumbered by federal or state regulatory requirements to demonstrate compliance with the NO2 NAAQS using AERMOD, EPA’s dispersion model, because the new NAAQS greatly reduces the compliance margin. AERMOD was developed and validated with a primary focus on larger sources with taller stacks, such as electric utility boilers, which results in model conservatism for sources such as compressor stations with shorter stacks that result in near-field modeled impacts. However, a comprehensive dataset was not available to understand AERMOD conservatism. This project developed a comprehensive dataset based on 13 months of monitoring at a compressor station in Oklahoma, including ambient monitoring of ozone and oxides of nitrogen (NOx), meteorological data, and reciprocating engine emissions. This final report summarizes planning and execution of the data collection effort, reviews the resulting dataset, and provides an initial assessment of AERMOD performance based on this dataset. In addition to this report, the dataset will be released to EPA and the public so that it is accessible to the modeling community for other projects that are investigating specific aspects of AERMOD performance.
This includes both the report and the associated data in Excel format.