Pennsylvania is among the states taking initial steps required by federal regulations toward identifying areas experiencing unhealthful levels of airborne sulfur dioxide (SO2) and then developing programs to control emissions of the pollutant from industrial facilities within those areas. The targeted facilities should include larger electric generating or industrial facilities, or smaller, clustered units, whose operations rely on burning coal or other sulfur-bearing fuels and which may not yet have fully deployed SO2 emission control systems.
At this stage, states are first identifying for evaluation those facilities most likely to contribute to excessive airborne pollutant levels. For example, on January 15, 2016, Pennsylvania’s Department of Environmental Protection (DEP) submitted to the U.S. Environmental Protection Agency a list of 30 larger (more than 2,000 tons per year of SO2 emitted) or clustered facilities whose impact on ambient SO2 levels DEP will be evaluating.
Federal regulations (EPA’s so-called “Data Requirements Rule”) requires states to submit lists of the facilities they will evaluate in order to classify whether affected areas are attaining the most recent National Ambient Air Quality Standards for SO2. EPA promulgated the updated, significantly more stringent SO2 standards in 2010. To date, states and EPA have lacked sufficient monitor stations in the field to determine whether many regions of the United States are meeting the new ambient SO2 concentration standards, which EPA has deemed to define threshold healthful concentration levels with an adequate margin of safety.
Under the Data Requirements Rule and a related federal court consent decree in effect but still subject to further appeal, a state is next required to notify EPA by July 1, 2016, which of the listed facilities it will address through:
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monitoring ambient SO2 concentrations;
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projecting ambient impacts of that facility’s SO2 emissions by modeling those impacts calculated using computer algorithms accounting for matters such as local meteorology or terrain; and
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imposition of tighter SO2 emission limitations.
If a state chooses monitoring for a facility, field monitors must be in place and operational by January 1, 2017, and determinations of attainment or nonattainment for the affected area must be made by EPA by 2020, based on monitoring data collected from 2017 through 2019. If modeling is chosen, a state must submit its modeling analysis for the subject facility to EPA by January 13, 2017, and EPA will reach an attainment or nonattainment designation for the affected area by the end of 2017. Under applicable federal and state law, if a facility’s emissions cause or significantly contribute to an area’s nonattainment designation, that facility is likely to be subject to stricter SO2 emission control requirements to help eliminate that nonattainment condition.
Alternatively, if the state chooses to impose sufficiently tightened SO2 emission limits for a facility instead of monitoring or modeling, those limits must be legally in place and enforceable by January 13, 2017.
State agencies like Pennsylvania's DEP that have submitted to EPA its list of facilities to evaluate can be expected to work with its listed facilities over the next few months to decide how it will meet the federal requirements.
