The U.S. Environmental Protection Agency will say in a notice to be published in the Dec. 21 Federal Register that it is approving into the Illinois Regional Haze State Implementation Plan (SIP) a variance for the electrical generating units (EGUs) included in the Ameren Multi-Pollutant Standard Group (Ameren MPS Group).
The Ameren MPS Group consists of five facilities owned by Illinois Power Holdings LLC (IPH) and two facilities owned by AmerenEnergy Medina Valley Cogen LLC. The Illinois Environmental Protection Agency (IEPA) submitted the variance to EPA for approval in September 2014. This final rule is effective 30 days after this publication in the Federal Register. IPH is owned by Dynegy (NYSE: DYN).
In June 2011, Illinois submitted a plan to address the requirements of the Regional Haze Rule, and EPA approved Illinois’ Regional Haze state implementation plan (SIP) in July 2012. In its approval, EPA determined that the emission reductions from sources included in the Illinois plan are significantly greater than even conservative definitions of best available retrofit technology (BART) applied to BART subject units under the haze rule.
EPA also addressed whether the Illinois plan can also be expected to achieve greater visibility protection than application of BART on BART-subject units. Given that, in general, the Illinois power plants are substantial distances from any Class I area, and given that the averaging in Illinois’ plan is only authorized within the somewhat limited region within which each utility’s plants are located, EPA determined that a reallocation of emission reductions from one plant to another is unlikely to change the visibility impact of those emission reductions significantly. Consequently, EPA concluded that the significantly greater emission reductions that Illinois required in its Regional Haze SIP will yield greater progress toward visibility protection as compared to the benefits of a conservative estimate of BART.
One of the rules approved in that action to meet BART requirements is the Multi-Pollutant Standard (MPS), specifically subsections (a), (b), (e), and (g).
- Section 225.233(e)(3)(C) contains the sulfur dioxide (SO2) emission standards applicable to the Ameren MPS Group.
- Section 225.233(e)(3)(C)(i) establishes an overall SO2 annual emission rate for EGUs in the Ameren MPS group of 0.50 pounds per million Btu (lb/mmBtu) for calendar years 2010 through 2013.
- Section 225.233(e)(3)(C)(ii) establishes an overall SO2 annual emission rate for EGUs in the Ameren MPS group of 0.43 lb/mmBtu for calendar year 2014.
- Section 225.233(e)(3)(C)(iii) establishes an overall SO2 annual emission rate for EGUs in the Ameren MPS group of 0.25 lb/mmBtu for calendar years 2015 and 2016.
- Section 225.233(e)(3)(C)(iv) establishes an overall SO2 annual emission rate for EGUs in the Ameren MPS group of 0.23 lb/mmBtu beginning in calendar year 2017 and continuing each calendar year thereafter.
In November 2013, the Illinois Pollution Control Board (IPCB) granted IPH and Medina Valley a variance from the applicable requirements of Section 225.233(e)(3)(C)(iii) for a period beginning Jan. 1, 2015, through Dec. 31, 2019, and Section 225.233(e)(3)(C)(iv) for a period beginning Jan. 1, 2017, through Dec. 31, 2019, subject to certain conditions.
The coal-fired IPH facilities included in the Ameren MPS Group and subject to the variance are Coffeen Energy Center (Montgomery County), Duck Creek Energy Center (Fulton County), E.D. Edwards Energy Center (Peoria County), Joppa Energy Center (Massac County), and Newton Energy Center (Jasper County).
The Medina Valley facilities included in the Ameren MPS Group and subject to the variance are the coal-fired and now-retired Meredosia Energy Center (Morgan County) and the Hutsonville Energy Center (Crawford County).
IEPA submitted the variance as a revision to the Illinois Regional Haze SIP in September 2014.
EPA proposed to approve the variance on April 20 of this year. As discussed in the proposal, the variance results in less SO2 emissions than the currently approved Regional Haze SIP. In addition, EPA determined that the significantly lower SO2 emissions under the variance versus application of Best Available Control Technology (BACT) to BART-subject sources, will yield greater progress toward visibility protection. Finally, with respect to the requirements of section 110(l) of the Clean Air Act (CAA), because the variance will result in less SO2 emissions than the currently approved Regional Haze SIP and will continue to provide better visibility protection than the application of BART to BART-subject units, EPA has determined that the variance will not interfere with attainment, reasonable further progress, or any other applicable requirement of the CAA.
In the notice, EPA responds to various comments on this variance. For example:
- One commenter said the IEPA has not met its burden to show that the Multi-Pollutant Standard is approvable as a BART alternative because it has not performed modeling of the visibility impacts for the MPS compared to BART. “EPA disagrees with the commenter that visibility modeling is required. EPA found in its original approval of Illinois’ BART plan that the distances from the relevant power plants to the affected Class I areas are substantial and that the averaging in Illinois’ plan is only allowed within somewhat limited regions.”
- A commenter said the variance from the MPS authorizes the IPH fleet to emit greater SO2 emissions than would be emitted if BART were required, and thus EPA cannot find that the MPS will lead to greater reasonable progress than would BART. Of the seven plants included in the original Ameren MPS Group, five plants still in operation are now owned and operated by IPH and two plants that retired in 2011, Hutsonville and Meredosia, are now owned by Medina Valley and are no longer part of the fleet. Because of the variance, the MPS will no longer require SO2 reductions from the IPH coal fleet during the period of the first long-term strategy for regional haze (i.e., before 2018) that are greater than the reductions that would result from requiring IPH to install and operate BART on its BART-subject plants. “EPA disagrees with the commenter’s assertion that EPA cannot find that the MPS will lead to greater reasonable progress than would BART. The premise of the commenter’s analysis, that only currently operating units in the IPH fleet should be evaluated, is flawed.”