The U.S. Environmental Protection Agency will announce in the June 15 Federal Register that it is proposing to approve a State Implementation Plan (SIP) revision submitted by the North Carolina Division of Air Quality (NC DAQ) in May 2013 saying that coal-fired power plant shutdowns and fuel switches are helping the state meet regional haze reduction goals.
North Carolina’s May 2013 SIP Progress Report addresses requirements of the Clean Air Act and EPA’s rules that require each state to submit periodic reports describing progress towards reasonable progress goals (RPGs) established for regional haze and a determination of the adequacy of the state’s existing SIP addressing regional haze. EPA is now proposing to approve the Progress Report and will take comment for 30 days on that intent for 30 days after June 15.
In its regional haze plan, North Carolina identified SO2 emissions from coal-fired electric generating units (EGUs) as the key contributor to regional haze in the region. North Carolina discussed the status of its own, aggressive Clean Smokestacks Act (CSA) emissions reduction program, which the state identified as the primary state control strategy in its regional haze plan, and the resulting emissions reductions.
Under the CSA, power plants were required to reduce their NOx emissions by 77% in 2009 and their SO2 emissions by 73% in 2013. The state notes that all of the CSA subject units are controlled with a scrubber for SO2 control and a selective catalytic reduction unit or a selective non-catalytic reduction for NOx control, or have retired, which will result in more SO2 and NOx emissions reductions than those projected in the regional haze plan.
In its Progress Report, North Carolina presents SO2 emissions data for EGUs in the state and notes that North Carolina’s EGU sector represents over 50% of statewide SO2 emissions from stationary sources. SO2 emissions reductions from 2002 to 2011 for North Carolina EGUs (387,373 tpy) are greater than the SO2 emissions reductions from 2002 to 2018 estimated in North Carolina’s regional haze plan for these EGUs (367,528 tpy).
Additionally, the state updated the 2018 SO2 emissions projections for North Carolina EGUs in its regional haze plan. These updated 2018 SO2 EGU emissions projections are approximately 80% lower than the projected 2018 SO2 emissions in the regional haze plan.
North Carolina states that coal-fired EGUs in North Carolina emitted a total of 370,000 tpy of SO2 in 2007, whereas in 2011, these same EGUs emitted a total of 73,000 tpy of SO2, a reduction of 297,000 tpy, due largely to the installation and operation of scrubbers. The state expects that future SO2 emissions will decline further from more natural gas use and the continued retirement of older, smaller coal-fired EGUs without scrubbers.
NOx emissions from these EGUs dropped from a total of approximately 57,400 tpy in 2007 to approximately 39,300 tpy of NOx in 2011, an 18,100 tpy reduction.
North Carolina identified the retirement of over 100 EGUs at 35 facilities located in eight nearby states that modeling indicates potentially impact visibility in North Carolina’s Class I areas. These units emitted more than 550,000 tpy of SO2 in 2011. The state believes that this is another indicator that the Class I areas in North Carolina are on track to meet their haze goals.
The two primary utilities serving North Carolina with in-state coal plants are the Duke Energy Progress and Duke Energy Carolinas units of Duke Energy (NYSE: DUK).