American Electric Power (AEP) proposed to construct a 600 megawatt super critical pulverized coal plant near Fulton, AR, which is located approximately 90 kilometers from the nearest Class I Area. Under the Clean Air Act, Class I areas, which include national parks, memorial parks, and wilderness areas, receive special protection from impacts of air pollutants. The proximity to the protected Class I Area subjected the project to rigorous analyses to demonstrate compliance with allowable PSD increment concentrations of SO2, NOx and PM10, as well as air quality related values (AQRVs) that include visibility degradation and deposition of sulfur and nitrogen.
TRC developed a site specific modeling protocol and negotiated concurrence on numerous technical issues with the appropriate Federal Land Managers (FLMs), EPA Regional Office and the Arkansas Department of Environmental Quality (ADEQ). The resulting modeling analysis indicated significant impacts of SO2 and PM10 at the Class I areas which required a multisource modeling demonstration of compliance with the allowable increment concentrations. Refined multisource modeling analyses resulted in predicted violations of the allowable increments’ presenting additional difficulties for project permitting. TRC undertook a detailed evaluation of contributing sources and worked closely with EPA and nearby state agencies to develop a multisource emission inventory encompassing four states and hundreds of sources and successfully demonstrated that the proposed AEP project would not contribute significantly to any predicted violations thus clearing the way for permit issuance. Impacts on visibility, based on the most conservative modeling scenarios, also indicated potential impacts above threshold levels. TRC worked closely with the FLMs to develop a visibility impact mitigation plan that was approved and implemented to the satisfaction of the FLMs, EPA and ADEQ.
TRC assisted AEP and worked with the appropriate regulatory agencies to identify and overcome potential project fatal flaw impacts at the Class I areas of concern. TRC's technically and scientifically based solutions have withstood numerous legal challenges from project opponents and interveners. AEP was issued a PSD construction permit, has completed construction, and the plant is in commercial operation.