EPA to Reject Claims of Maryland and Delaware that Upwind Power Plants Have Inadequate NOx Controls
June 7, 2018
EPA has proposed to deny petitions from Delaware and Maryland that sought to force controls on power plants in Indiana, Kentucky, Ohio, Pennsylvania and West Virginia. The petitions claimed that NOx emissions from coal-fired plants in these states were significantly contributing, or would contribute in the future, to ozone levels in Delaware and Maryland that exceed allowable ambient levels.
EPA’s proposal recounts the history of efforts to control cross-state air pollution under the Clean Air Act and identifies individual “upwind” power stations that Delaware and Maryland claim lack adequate controls. EPA applied its so-called “good neighbor” test to evaluate the petitions, deciding first whether the identified emissions were significantly contributing to ozone violations in the downwind states and then determining whether those emissions could be controlled through the use of “highly cost effective controls.”
In the case of Delaware’s petition, EPA first found that Delaware had not demonstrated that is has or is likely to have ozone attainment issues. Second, it found that Delaware’s modelling to demonstrate the responsibility of individual power plants wrongly relied on 2011 data because ”2011 emissions are generally higher than, and therefore not representative of, current or future projected emissions levels at these [plants].”
Maryland’s petition argued that 36 individual plants were operating their post-combustion controls “sub-optimally” in comparison to the lowest observed emissions rate at those plants. EPA noted that the lowest observed emissions rate cannot be regarded as consistently achievable. EPA instead did its own analysis using NOx emissions data over a 6-year period and decided to use the third lowest fleet-wide average NOx rate. Using this rate, EPA concluded that Maryland had overstated the sustainable emissions rate.
In addition, EPA reviewed the claims in the petitions about individual power plants and found that EPA has already determined that those plants are implementing highly cost effective controls and that there is no basis for further imposition of controls on them. Nor did EPA find evidence that the plants were not utilizing their control technologies during ozone production season.
EPA will accept comments for 45 days from the date its proposal is published in the Federal Register.