EPA Determines Upwind States Need Impose No New Measures to Prevent Downwind Ozone Pollution

Policy Details

Policy Details

Last Action
Final rule published in Federal Register.
Date of Last Action
Dec 21 2018
Date Introduced
Jul 10 2018
Publication Date
Jan 12 2019
Date Made Public
Jul 10 2018

SciPol Summary

On December 21, 2018, the EPA issued a final rule confirming its conclusion that nearly two dozen eastern states need do nothing further to comply with their Clean Air Act (CAA) obligations to avoid sending NOx, a precursor to ozone pollution produced in large part by the electric power industry, downwind to neighboring states. 

EPA had determined in 2015 that those states had failed to develop adequate state implementation plans (SIPs) to comply with the Good Neighbor Provision of the Clean Air Act, which requires them to curb emissions of pollutants that prevent downwind states from meeting national ambient air quality standards (NAAQS) for ozone.  This set up a series of deadlines in 2017 and 2018 for EPA to impose federal implementation plans (FIPs) that curbed these emissions. 

In October 2016, the Obama EPA issued an update to its 2011 Cross State Air Pollution Rule (CASPR), that imposed FIPs requiring these states to undertake a series of cost-effective, immediately available measures to curb NOx pollution that could be implemented by the 2017 summer ozone season to comply with a July 2018 deadline.  These included mainly placing controls on NOx pollution from electricity generating units (EGUs).  The EPA concluded, however, that this was only a “first step to address interstate transport for the 2008 ozone NAAQS” and that “any remaining obligation that might be achievable on a longer timeframe in a separate rulemaking.”  It expressed its intent to “continue to collect information and undertake analyses for potential future emission reductions at non-EGUs that may be necessary to fully quantify states’ interstate transport obligations in a future action.” 

With the December 21, 2018 final rule, EPA has now concluded that no further action is necessary. To reach this conclusion, determined that coal-fired power plant retirements, coal-to-gas conversions, the introduction of new technology, and power plant efforts to comply with the separate regional haze program would bring the upwind states into compliance with the Good Neighbor Provision for ozone by 2023. EPA chose 2023 as its “analytic year,” on the logic that practical considerations meant that few or no additional controls could be deployed before that year. 

The final rule will go into effect on February 29, 2019. Downwind states, who have undertaken court challenges to force EPA to bring the upwind states into compliance with the CAA’s Good Neighbor Provisions, can be expected to challenge EPA’s decision to require no further action. 

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