Sierra Club slams Illinois board for approving air emissions plan for coal units

The Sierra Club claimed in an Oct. 2 statement that the Illinois Pollution Control Board on Oct. 1 let coal-fired generation off too lightly, even though that approved rulemaking covers four coal-fired units that are being switched to other, cleaner fuels.

The board on Oct. 1 approved a plan from the Illinois Environmental Protection Agency (IEPA) to reduce air pollution in the Peoria and Lemont areas. The U.S. Environmental Protection Agency (U.S. EPA) has designated the air in parts of Cook, Will, Tazewell and Peoria counties unsafe to breathe due to high levels of SO2 pollution. The largest sources of SO2 impacting these “non-attainment areas” are NRG Energy’s (NYSE: NRG) Will County and Powerton coal plants as well as Dynegy‘s (NYSE: DYN) E.D. Edwards coal plant, the club said.

IEPA’s plan exempts NRG from installing SO2 controls at the Will County plant as required under state law and also establishes a lenient monthly averaging limit for pollution from NRG’s Powerton plant, the club said. The plan will now be heard before Illinois General Assembly members on the Joint Committee on Administrative Rules (JCAR) and then Region 5 of the U.S. EPA.

Christine Nannicelli, Campaign Representative with the Sierra Club’s Beyond Coal campaign, said: “For decades the residents in the Will County and Peoria areas have been overburdened by air pollution, much of which comes from the Will County, E.D. Edwards, and Powerton coal plants. The state plan put forward by the IEPA and rubber stamped by the Pollution Control Board fails to adequately protect families living next to these huge sources of dangerous pollution. We join the hundreds of residents in the Will County and Peoria areas to call on members of JCAR and the U.S. EPA to send this plan back to be strengthened.”

Much of this action is related to the state’s 2007 Combined Pollutant Standard (CPS), which sets specific air emissions limits for groups of power plants. The CPS provides alternate means to comply with mercury emissions standards by shutting down units and installing pollution control technology for NOx, SO2, and particulate matter emissions that also reduce mercury.

Electric generating units at Midwest Generation’s five power plants are subject to the CPS: units 6, 7 and 8 at the Joliet Station; units 5 and 6 at the Powerton Station; units 6, 7, and 8 at the Waukegan Station; units 1, 2, 3, and 4 at the Will County Station; unit 19 at the Fisk Station; and units 7 and 8 at the Crawford Station. Among other requirements in the CPS, electric generating units must comply with a group annual average SO2 emission limit and NOx emission limit. Fisk and Crawford were retired earlier this decade.

Board was addressing SO2 needs under the NAAQS

The rulemaking that got the Oct. 1 board decision generally proposes to control SO2 emissions to implement the 2010 NAAQS for SO2. In sum, the Illinos EPA’s proposal has three main outcomes: establish SO2 emission limits for specific sources; establish sulfur content limits for liquid fuels used by fuel combustion emission units throughout the state; and address the conversion of certain coal-fired electric generating units to fuel other than coal.

The agency proposed to create new Subpart AA to Part 214 requiring eight particular sources to comply with SO2 emission limits. The eight stationary sources covered by proposed Subpart AA are:

  • Aventine Renewable Energy (located at Pekin);
  • Illinois Power Holdings, E.D. Edwards (Bartonville)
  • Ingredion (Bedford Park)
  • Midwest Generation, Joliet (Joliet)
  • Midwest Generation, Powerton (Pekin)
  • Midwest Generation, Will County (Romeoville)
  • Owens Corning (Summit)
  • Oxbow Midwest Calcining (Lemont)

The proposed SO2 limits are hourly numeric limits on 36 emission units at these sources. For one source, Midwest Generation’s Powerton coal station, the agency proposed compliance with the emission limit on a rolling 30-day average basis. The agency intends that the proposed limits will be adequate to attain the 2010 NAAQS for SO2 in both the Lemont and Pekin nonattainment areas.

Units can achieve the hourly limits by using pollution control equipment, switching fuels, or operational changes. For example, Joliet 6, 7, and 8, and Will County 3 will perform fuel conversion away from coal. Aventine Renewable Energy anticipates converting to natural gas combustion, and Owens Corning anticipates reconfiguring its operations.

The agency also proposed limits on sulfur content in fuel for all stationary sources burning diesel fuel in Illinois. Specifically, units must comply with sulfur content limits of 1000 parts per million for residual fuel oil and 15 parts per million for distillate fuel oil, with certain exceptions.

Four coal units to be converted to gas and diesel fuel

Midwest Generation informed the Illinois EPA that it plans to convert electric generating units in the Lemont nonattainment area to use fuel other than coal such as natural gas or distillate fuel oil. Specifically, Midwest Generation intends to convert Joliet 6, 7, and 8 and Will County 3. The agency proposed amendments, therefore, to address conversion of these units. The agency proposed amendments to Parts 214 and 225 that require these four Midwest Generation units permanently to cease combusting coal.

Midwest Generation intends to continue combusting coal at Will County 4, and requested from the agency that the unit be exempt from the requirement to shut down or install flue gas desulfurization (FGD) equipment by Dec. 31, 2018, in lieu of a Joliet unit having such exemption.  

Illinois Power Resources Generating LLC (IPRG) owns and operates the coal-fired E.D. Edwards facility. IPRG stated that the SO2 emission limits for E.D. Edwards identified in the Illinois EPA proposal are the result of a memorandum of agreement between IPRG and the agency wherein IPRG agreed to a 92.2% reduction in the allowable SO2 limits at the E.D. Edwards facility two years in advance of the 2017 deadline for implementation of emission reductions needed to demonstrate attainment with the 2010 NAAQS for SO2.

Under the current CPS requirements, Midwest Generation units are required to meet annual emission standards for SO2. The SO2 group rate starting in 2019 is the most stringent rate at 0.11 lb/mmBtu. Under the proposal, the anticipated SO2 emission rates for the Joliet units are 0.0006 lb/mmBtu and 0.0015 lb/mmBtu for Will County 3 not burning coal. The very low SO2 emission rates for these four units correspond to the change in fuel from coal and are orders of magnitude smaller than the CPS rate. The agency predicts that annual SO2 emissions at the Will County station overall will decrease as compared to emissions under the current CPS due to the proposed prohibition on burning coal in Will County 3. The agency projects that SO2 emissions from Will County 3 will decrease from 3,144 tons in 2014 to 13 tons in 2017 assuming that the unit burns ultra-low sulfur diesel of less than 15 parts per million sulfur content.

Four ex-coal units can’t be used to help achieve the CPS averaging goal

The agency calculates that Will County 3 and 4 together will emit 2,261 tons in 2017 under the proposed rules as compared to 3,515 tons under the CPS. The agency’s proposal, therefore, results in an overall reduction in annual SO2 emissions at the Will County station. Under the agency’s proposal, units continuing to burn coal, namely Will County 4 and units at Powerton station and Waukegan station, will continue to be subject to the CPS annual SO2 emission rate. The CPS requires units in Midwest Generation’s CPS group to meet a group-wide average limit for SO2 emissions. These emission rates are 0.15 lb/mmBtu in 2017, 0.13 lb/mmBtu in 2018, and 0.11 lb/mmBtu in 2019. The agency proposed that the units converting to fuel other than coal will no longer be subject to the CPS group average annual SO2 emission rate. This is because, were the units to remain a part of the CPS group-wide average, they would be “essentially emitting no SO2” and “it would lead to the coal-fired units possibly being able to emit greater amounts of SO2 and offsetting the benefits of the natural gas units.” Removing the four converted units from Midwest Generation’s CPS group will therefore make the CPS annual SO2 emission rate more stringent for the units that remain than if the converted units remained in the CPS.

The agency also noted that Midwest Generation is projecting the converted units will only operate at approximately 10% capacity, resulting in a heat input reduction that will reduce total NOx tonnage emissions from the CPS units by more than 3,000 tons (23% from the group statewide).

Said the Oct. 1 approval: “The Board agrees that the Agency’s proposal will result in greater SO2 reductions across the Midwest Generation CPS group than under the current CPS. The proposal also results in emission reductions for NOx, carbon dioxide, particulate matter, and mercury. The proposal makes no change to the numeric annual SO2 emission rate in covering Midwest Generation’s CPS group.

It also added: “The Board finds that the proposed 30-day average limit is appropriate. USEPA reviewed and approved of the proposed limit on Powerton of 3,452 lbs/hr measured on a 30-day rolling average basis. USEPA further approved a supplemental limit not to exceed 6000 lbs/hour in more than 5% of stack operating hours. The Board finds that the supplemental limit suggested by the Agency addresses the participants’ concern regarding emission spikes above the modeled critical value by placing a limit on the number of stack operating hours during which the emissions can exceed the modeled hourly limit. Furthermore, the 30-day average rate of 3452 lbs/hr is 42 percent lower than the modeled one-hour rate of 6000 lbs/hr that would have been proposed for this unit without 30-day averaging. Accordingly, the Board is convinced that the proposed Powerton 30-day average limit of 3452 lbs/hr coupled with the supplemental limit is comparably stringent to the hourly average limit of 6000 lbs/hr and is sufficiently protective of the NAAQS.”

The Oct. 1 ruling also said: “Based on the rulemaking record, the Board agrees with the Agency’s position that the proposal will achieve attainment in the Lemont nonattainment area even with an FGD exemption for Will County 4. Will County 4’s impact on the most impacted receptor in the Lemont nonattainment area, and the total impact of all modeled sources on that receptor, is less than the NAAQS design value of 196.32 µg/m3. The amended 5,000 lb/hr limit, as opposed to the previous 6,520.65 lb/hr limit, is a 23 percent reduction in Will County 4’s allowable emissions and will further reduce the impact at this receptor to roughly 161.5 µg/m3 , well below the NAAQS design value of 196.32 µg/m3.”

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.