The U.S. Environmental Protection Agency will propose in a notice in the Jan. 11 Federal Register to approve a state implementation plan (SIP) revision submitted by the State of Maryland that regulates NOx emissions from seven coal-fired plants in the state.
Written comments must be made within 30 days after the date of publication in the Federal Register.
In November 2015, the Maryland Department of the Environment (MDE), submitted a revision to its SIP seeking to include a new NOx regulation in the Maryland SIP. On Sept. 8, 2016, MDE provided a letter to EPA to clarify that this regulation was submitted as a SIP-strengthening measure, and not as a submission to address reasonably available control technology (RACT) for coal-fired electric generating units (EGUs).
The affected units for the regulation are Brandon Shores Units 1 and 2, C. P. Crane Units 1 and 2, Chalk Point Units 1 and 2, Dickerson Units 1, 2, and 3, H.A. Wagner Units 2 and 3, Morgantown Units 1 and 2, and Warrior Run. The regulation requires an affected EGU to minimize NOx emissions by operating and optimizing the use of all installed pollution controls and combustion controls during all times that the unit is in operation while burning coal. For demonstrating compliance with this requirement, the owner or operator is required to submit a plan to MDE and EPA for approval that summarizes the data to be collected to show that each affected EGU is operating its installed controls.
The regulation establishes a system-wide emissions rate of 0.15 pounds per million British thermal units (lbs/mmBtu) on a 30-day rolling average for coal-burning EGUs during the ozone season. System-wide emissions are an aggregation of NOx emissions from all coal-fired EGUs owned, operated, or controlled by the same company. The 0.15 lb/mmBtu emission rate does not apply to C. P. Crane and AES Warrior Run, as they are not a part of a system. To demonstrate compliance with the requirement to optimize controls, MDE established 24-hour block emissions levels for each coal-burning EGU based on historical emissions data. During the ozone season, EGU owners are required to provide a daily report for any unit that exceeds its 24-hour emissions level. The report requires specific operating data and an explanation of any exceedances of the 24-hour level.
The 14 affected units at the seven plants have all installed controls as a result of programs requiring NOx reductions by previous regulatory requirements such as the NOx SIP Call, the Clean Air Interstate Rule (CAIR), the Cross State Air Pollution Rule (CSAPR) and Maryland’s Healthy Air Act (HAA). All of the affected units have either selective catalytic reduction (SCR), selective non-catalytic reduction (SNCR), or selective alternative catalytic reduction (SACR). EPA finds that the submittal strengthens the Maryland SIP. The NOx emissions limits plus the operation and optimization of the existing NOx controls whenever the units are in operation will help Maryland’s attainment and maintenance of the 2008 ozone NAAQS.