Illinois EPA issues modified permit for Ameren’s Coffeen coal plant

After a first such permit issued in 2005 was appealed, the Illinois Environmental Protection Agency on Oct. 17 issued a revised air permit for the coal-fired, 895-MW Coffeen power plant of Ameren (NYSE: AEE).

This, by the way, is one of the coal plants that Ameren plans to sell to Dynegy (NYSE: DYN), pending a decision by the Illinois Pollution Control Board that would transfer an air-compliance break for the coal plants from Ameren to Dynegy.

The Illinois EPA on Oct. 17 issued a modified Clean Air Act Permit Program (CAAPP) permit to Ameren Energy Generating for the Coffeen Energy Center. The plant has two coal-fired boilers and qualifies as a major source of emissions under Illinois’ Clean Air Act Permit Program (CAAPP).

The Illinois EPA issued the initial CAAPP permit for Coffeen in September 2005. Ameren appealed this permit to the Illinois Pollution Control Board, contending that a number of conditions in the permit were erroneous or unwarranted. In February 2006, the board accepted Ameren’s petition for appeal and granted an administrative stay of the issued CAAPP permit in its entirety.

Ameren and the Illinois EPA, with the assistance of the Illinois Attorney General, have since then been engaged in discussions to resolve the permit appeal. There were three steps in the process for the resolution of the appeal.

  • The first step was to lift the administrative stay of the initial CAAPP permit for Coffeen. The Illinois EPA and Ameren jointly filed a motion with the board in September 2012 requesting that the stay be lifted with respect to conditions of the permit that were not being contested in the appeal. In September 2012, the board granted this motion and the initial CAAPP permit for Coffeen took effect.
  • The next step, which is the step that occurred on Oct. 17, is for the Illinois EPA to issue a modified CAAPP permit to resolve contested permit conditions. Because a significant change in this CAAPP permit triggered requirements of the U.S. EPA’s rules, Ameren submitted the information required by these rules, including a Compliance Assurance Monitoring (CAM) plan for emissions of particulate matter (PM). Along with the changes to the initial CAAPP permit that were made as part of resolution of the appeal, other conditions have been added in the modified permit to address CAM, including conditions that provide conditional approval of Ameren’s plan. Ameren did not submit a CAM plan with specific indicator ranges because of the absence of appropriate test data for the PM emissions of the boilers with concurrent data for opacity and the operation of the flue gas desulfurization (FGD) systems now installed on these boilers. The conditional approval of the CAM plan requires Ameren to conduct PM emission testing to establish indicator ranges, submit those ranges to the Illinois EPA and begin operation of the monitoring within 180 days of the issuance of the modified permit.
  • The third step in the settlement of the appeal, which is in its initial stages of development, is the formal reopening of the CAAPP permit for Coffeen. In this step, new requirements that have been adopted under the Clean Air Act since the original permit was issued, which are now applicable to Coffeen, will be added into the permit. Key rules for the emissions of coal-fired utility boilers that have been adopted since the CAAPP Permit for Coffeen was initially issued that would be addressed in the reopening proceeding include the Clean Air Interstate Rule (CAIR) and the Mercury and Air Toxics Standards (MATS). Ameren is already subject to and complying with the relevant requirements of CAIR. The initial compliance date for MATS is in April 2015.

Illinois EPA tells commenters it worked within the law it had

Illinois EPA issued a responsiveness summary of criticisms lodged by commenters during this permitting process, and its answer to them. For example, in response to a comment that there are systemic flaws in the permitting regime, the agency wrote: “The Illinois EPA disagrees that there are deficiencies with the process set forth in the applicable laws and regulations. However, if any such deficiencies with the process exist, it is a product of the statutory and/or regulatory framework of the Title V permitting program, which largely derive from the Clean Air Act and federal regulations implementing the same, and cannot be cured by way of this permitting action.”

The two boilers at the plant, which began operation in 1965 and 1972, have nominal capacities of 3,282 and 5,544 mmBtu/hour, respectively. In addition to coal, these boilers also fire fuel oil as auxiliary fuel during startup and for flame stabilization. Periodically small amounts of used oil or boiler cleaning residue are fired with the coal in these boilers.

Ameren notes on its website that more than $900m has been spent to install and improve pollution control equipment at Coffeen in the past decade. In addition to the new FGD, these improvements include precipitator upgrades on Unit 1 and a new precipitator on Unit 2, new selective catalytic reduction systems as well as a host of other equipment and systems. Since 2008, NOx emissions have been reduced by 80% and SO2 emissions have been reduced by over 95%.

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.