Several power plants targeted in EPA regional haze plan for Arkansas

The Sierra Club on March 11 applauded the release by the U.S. Environmental Protection Agency of a plan to address regional haze pollution that is affecting air quality at national wilderness areas and other federal lands in Arkansas and Missouri.

Under the Regional Haze Rule, states are required to develop plans to clean up pollution and improve air quality at national parks and wilderness areas. The Arkansas Department of Environmental Quality put forward a limited plan in 2008 that did not fully meet EPA requirements, the club said. The EPA’s new proposal fully addresses these requirements and ensures that emissions from some of the largest smokestacks in Arkansas are reduced.

Said Glen Hooks, director of the Sierra Club’s Arkansas chapter: “The facilities affected by this rule have some decisions to make: They can continue operating old, outdated plants or transition to cleaner forms of power. The Sierra Club believes that clean air is achievable without major investments in an aging power fleet. It’s time for Arkansas to get in the game and move to renewable, homegrown energy solutions — as many neighboring states already have. And we look forward to working with stakeholders to find the lowest-cost plan to protect our communities, environment, and economy here in the Natural State.”

The EPA Region 6 Deputy Regional Administrator, Sam Coleman, signed this proposed plan on March 6, and the agency has issued it ahead of its publication in the next few days in the Federal Register. Comments on it are to be taken until May 16.

“The EPA is proposing to promulgate a Federal Implementation Plan (FIP) to address certain regional haze and visibility transport requirements for the State of Arkansas,” said the EPA proposal. “This FIP would address the requirements of the Regional Haze Rule (RHR) and interstate visibility transport for those portions of Arkansas’ State Implementation Plan (SIP) we disapproved in our final action published on March 12, 2012.

“Specifically, the proposed FIP addresses the requirements for Best Available Retrofit Technology (BART) for those sources for which we did not approve Arkansas’ BART determinations, Reasonable Progress Goals (RPGs), reasonable progress controls and a long-term strategy, as well as the interstate visibility transport requirements for pollutants that affect visibility in Class I areas in nearby states. Specific to the reasonable progress controls requirement, we are proposing in the alternative two options for controlling the emissions from the Entergy Independence Plant that is not subject to BART. Under Option 1, we are proposing controls for emissions of SO2, and NOX. If we take final action on this finding, the source will be subject to controls for both pollutants. Alternatively, under Option 2, we are proposing controls for only emissions of SO2 for this planning period. In particular, we are soliciting comments on the alternate proposed Options 1 and 2.”

Independence is a coal-fired plant of Entergy Corp. (NYSE: ETR).

EPA is also proposing:

  • SO2, NOX, and PM BART determinations for Unit 1 of the Arkansas Electric Cooperative Corp. (AECC) Carl E. Bailey station. Bailey Unit 1 is a wall-fired boiler with a gross output of 122 MW. The unit is currently permitted to burn natural gas and fuel oil. “We concur with AECC’s decision to focus the SO2 BART evaluation on fuel switching,” said EPA. “Switching to a fuel with a lower sulfur content is expected to reduce SO2 emissions in proportion to the reduction in the sulfur content of the fuel, assuming that the fuels have similar heat contents. Bailey Unit 1 burns primarily natural gas, but is also permitted to burn fuel oil.” It would impose no further limits for NOx and said that PM is taken care of with the fuel switch for SO2 control;
  • SO2, NOX, and PM BART determinations for Unit 1 of the AECC John L. McClellan station. McClellan Unit 1 is a wall-fired boiler with a gross output of 134 MW. The unit is currently permitted to burn natural gas and fuel oil. The fuel oil burned is currently subject to a sulfur content limit of 2.8% by weight. EPA is proposing that BART for McClellan Unit 1 is switching to fuels with 0.5% or lower sulfur content by weight. No new NOx limit is proposed, and the switching to lower-sulfur fuel would take care of the PM question;
  • SO2 and NOX BART determinations for Boiler No. 1 of the American Electric Power (AEP) Flint Creek plant, which only has one unit. Flint Creek is a dry bottom wall-fired boiler with a nominal generating capacity rating of 558 MW. The unit burns primarily low-sulfur western coal and is currently equipped with an electrostatic precipitator (ESP) and low NOX burners. New air controls, including an SO2 scrubber, are currently being installed. EPA proposes that BART for AEP Flint Creek Unit 1 is an emission limit of 0.06 lb/MMBtu on a 30 boiler-operating-day rolling average based on the installation and operation of the NID scrubber system. It proposes that NOX BART for Flint Creek Unit 1 is an emission limit of 0.23 lb/MMBtu on a 30 boiler-operating-day rolling average based on the installation and operation of a new low-NOx burner (LNB)/overfire-air (OFA) system.
  • SO2 and NOX BART determinations for Units 1 and 2 and SO2, NOX, and PM BART determinations for the Auxiliary Boiler of the Entergy White Bluff Plant. White Bluff Units 1 and 2 are identical tangentially-fired boilers with a maximum net power rating of 850 MW each. The boilers burn sub-bituminous coal as the primary fuel and No. 2 fuel oil or biofuel for start-up. Units 1 and 2 are currently equipped with ESPs for control of PM. The Auxiliary Boiler is a 183 MMBtu/hr auxiliary boiler that burns only No. 2 fuel oil or biodiesel, and its purpose is to provide steam for the start-up of the two primary boilers. EPA proposes that SO2 BART for White Bluff Units 1 and 2 is an emission limit of 0.06 lb/MMBtu on a 30 boiler-operating-day rolling average based on the installation of dry flue gas desulfurization (FGD) or another technology that achieves that level of control. It proposes to require compliance with this requirement no later than 5 years from the effective date of the final rule. EPA proposes that NOX BART for White Bluff Units 1 and 2 is an emission limit of 0.15 lb/MMBtu on a 30 boiler-operating-day rolling average based on the installation and operation of LNB/SOFA. There are new mandates for any covered emissions from the Auxiliary Boiler, since it runs so little.
  • NOX BART determination for Unit 4 of the Entergy Lake Catherine Plant. Lake Catherine Unit 4 is a tangentially-fired boiler with a nominal net power rating of 558 MW. It is permitted to burn natural gas and No. 6 fuel oil. Entergy’s analysis states that Lake Catherine Unit 4 has not burned fuel oil since prior to the 2001-2003 baseline period, currently does not burn fuel oil, and that Entergy does not project to burn fuel oil at the unit in the foreseeable future. Therefore, Entergy’s analysis addresses BART for a natural gas firing scenario and does not consider emissions from fuel oil firing. EPA approved Arkansas’ BART determinations for Lake Catherine Unit 4 for SO2 and PM for the natural gas firing scenario in its March 2012 final action. So the only thing to address here is NOX, with EPA proposing that NOX BART for Lake Catherine Unit 4 for the natural gas firing scenario is an emission limit of 0.22 lb/MMBtu on a 30 boiler-operating-day rolling average based on the installation and operation of Burners out of Service (BOOS). BOOS is a staged combustion technique in which fuel is introduced through operational burners in the lower furnace zone to create fuel-rich conditions, while not introducing fuel to other burners. The removal of fuel from certain zones reduces the temperature and the production of thermal NOX. Additional air is then supplied to the non-operational burners to complete combustion;
  • SO2 and NOX BART determinations for Power Boiler No. 1 and SO2, NOX and PM BART determinations for Power Boiler No. 2 of the Domtar-Ashdown Mill. The No. 1 boiler has a heat input rating of 580 MMBtu/hr and an average steam generation rate of about 120,000 lb/hr. The No. 1 boiler combusts primarily bark, but is also permitted to burn wood waste and other fuels. It is equipped with a traveling grate, a combustion air system, and a wet ESP. The No. 2 boiler has a heat input rating of 820 MMBtu/hr and an average steam generation rate of about 600,000 lb/hr. The No. 2 boiler combusts primarily pulverized bituminous coal, but is also permitted to burn bark, petroleum coke and other fuels. It is equipped with a traveling grate, combustion air system including OFA, multiclones for particulate removal, and two venturi scrubbers for removal of remaining particulates and SO2. EPA proposes that an SO2 baseline emission rate of 21.0 lb/hr satisfies SO2 BART for Boiler No. 1. It proposes that NOX BART for Boiler No. 1 is an emission limit of 207.4 lb/hr on a 30 boiler-operating-day rolling average. This limit is based on the boiler’s current NOX baseline emission rate. EPA proposes that SO2 BART for Boiler No. 2 is an emission limit of 0.11 lb/MMBtu on a 30 boiler-operating-day rolling average, which can be done with the existing scrubbers at 90% control efficiency. NOX BART for Boiler No. 2, as proposed by EPA, is an emission limit of 345 lb/hr on a 30 boiler-operating-day rolling averaging basis, based on the installation of LNB. EPA proposes that the current Boiler MACT PM standard of 0.44 lb/MMBtu satisfies the PM BART requirement for Boiler No. 2.

Independence also targeted for dry scrubber installation

The Independence plant has two nearly identical coal-fired units (Units 1 and 2) with a nameplate capacity of 900 MW each. Units 1 and 2 are tangentially-fired boilers that burn sub-bituminous coal as their primary fuel and No. 2 fuel oil or Bio-diesel as the start-up fuel.

EPA noted: “The two units at White Bluff and the two units at Independence are tangentially firing boilers having nameplate capacities of 900 MW and similar gross ratings. All four units burn coal from the Powder River Basin (PRB) of Wyoming with similar characteristics. All four units employ cold side ESPs for particulate collection. Other pertinent characteristics are similar. The layout of the White Bluff and Independence facilities are also very similar. Due to the similarity of these facilities, we applied the total annualized dry FGD and wet FGD costs we developed for the White Bluff units to the Independence units. However, we adjusted the costeffectiveness ($/ton) due to the differing baseline SO2 emissions from the units.”

For the reasonable progress requirements, EPA is proposing in the alternative two options for controlling the emissions from Independence that are not subject to BART. Under Option 1, under the reasonable progress requirements, it is proposing controls for emissions of SO2 and NOX for Units 1 and 2 of Independence. Alternatively, under Option 2, it proposing controls for only emissions of SO2 for the first planning period.

EPA proposes to require compliance with an emission limit of 0.06 lb/MMBtu for Independence Units 1 and 2 based on a 30 boiler operating-day rolling average basis. It proposes to find that this emission limit, which is based on the installation and operation of dry FGD, is cost-effective at $2,477 per SO2 ton removed for Unit 1 and $2,286 per SO2 ton removed for Unit 2, and would result in significant visibility benefits.

Due to the similarity of these facilities, EPA applied the total annualized LNB/SOFA cost developed by Entergy for White Bluff Units 1 and 2, with one line item revision, to Independence Units 1 and 2. However, it adjusted the cost-effectiveness ($/ton) due to the differing NOX emissions from the units. Since its proposed BART determination for the White Bluff facility is that LNB/SOFA is more cost effective (lower $/ton) than selective non-catalytic reduction (SNCR) or selective catalytic reduction (SCR), and that the additional visibility benefits obtained as a result of the greater level of control SNCR and SCR offer over combustion controls are not worth the additional cost of SNCR or SCR, it expects that the same would apply to Independence Units 1 and 2. Therefore, its evaluation of NOX controls for Independence Units 1 and 2 had a focus solely on LNB/SOFA. Upon evaluation of the four reasonable progress factors, EPA found that the installation and operation of LNB/SOFA at Independence Units 1 and 2 is estimated to cost $401/NOX ton removed at Unit 1 and $436/NOX ton removed at Unit 2, which the agency considers to be very cost-effective.

Under the options:

  • Under Option 1 for the Independence units, for the first planning period, EPA is proposing both an SO2 emission limit as described above and a NOX emission limit of 0.15 lb/MMBtu on a 30 boiler-operating-day averaging basis based on the installation and operation of LNB/SOFA.
  • Under Option 2, the agency is proposing only SO2 controls for Independence Units 1 and 2 under the reasonable progress requirements.

In addition to options 1 and 2, EPA is also soliciting public comment on any alternative SO2 and NOX controls that would address the regional haze requirements for Entergy White Bluff Units 1 and 2 and Entergy Independence Units 1 and 2 for this planning period. This includes, but is not limited to, a combination of early unit shutdowns and other emissions control measures that would achieve greater reasonable progress than the BART and reasonable progress requirements proposed for these four units in this rulemaking. 

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.