The fate of air pollution control rules for eight of Vistra Energy Corp.'s coal-fired power plants in central and southern Illinois will remain undecided for now.
The Illinois Pollution Control Board on Oct. 4 declined to adopt a proposal from the state Environmental Protection Agency to amend an existing multipollutant standard, or MPS, that the board adopted in 2006. Instead, the board, which oversees the state's environmental regulations, opened up a new review period for its own proposal to change standards for SO2 and nitrogen oxide, or NOx, emissions.
The Illinois EPA in October 2017 proposed changing the existing MPS rule primarily by combining two existing MPS groups into one group and replacing the existing rate-based emissions standards for SO2 and NOx, with mass-based standards. The agency developed the plan in response to a request from the company, then known as Dynegy and since acquired by Vistra, to amend the standard to "simplify compliance and allow Dynegy more operational flexibility and economic stability," according to the board's order. The Illinois EPA also said the change would result in fewer emissions.
Vistra backed the proposal, arguing that it would reduce allowable emissions while better enabling the company to respond to economic pressures facing its Illinois fleet. State Attorney General Lisa Madigan and several environmental groups objected to the change, contending that it would increase pollution and harm public health and the environment.
The board's proposal differs from the Illinois EPA's initial plan by reducing the annual mass caps for both SO2 and NOx and requiring further reductions of those caps when units are permanently or temporarily shut down. This board plan lowers the proposed annual mass-based caps for SO2 from 55,000 tons per year to 44,920 tons per year and for NOx from 25,000 tons per year to 22,469 tons per year.
The current standard now allows 66,354 tons of SO2 and 32,841 tons of NOx to be emitted each year. The 1,185-MW Baldwin Energy Complex, 915-MW Coffeen, 425-MW Duck Creek, 585-MW E.D. Edwards, 294-MW Hennepin Power Station, 1,002-MW Joppa Steam and 615-MW Newton plants fall under the standard. The 434-MW Havana 6 plant is also under the rule.
In its order, the board said while it could have sent the restructured plan ahead for review by a bipartisan group of lawmakers known as the Joint Committee on Administrative Rules, a better path is to give time for people to weigh in on the new proposal.
"This finding is bolstered by the on-going disagreements among the participants over these fundamental issues, as well as by the significance of this rulemaking, reflected in its high degree of public participation," the board said.
Vistra officials were still reviewing the order on Oct. 4 and did not yet have a comment.
The company had strongly endorsed the Illinois EPA plan, telling the board in June that it "would achieve significant reductions in allowable emissions, and enable Vistra to better supply the energy market by eliminating the need to dispatch units, or constrain unit operations, solely for the purpose of MPS compliance."
But those opposed to the plan said changing the standard could open the door for Vistra to potentially shut down, or operate less often, power plants with scrubbers, a form of SO2 controls, in favor of operating less-expensive power plants without scrubbers.
"If scrubbed plants are shut down and those MMBtu's are all shifted to unscrubbed plants, there is no debate that emissions levels would increase compared to the status quo," advocacy groups including the Environmental Defense Fund and Environmental Law and Policy Center said in comments filed in June.
Dynegy has installed scrubbers, a form of SO2 controls, at a number of its coal plants in Illinois including the Baldwin plant. Units at the Duck Creek, Havana 6 and Coffeen plants are also scrubbed, S&P Global Market Intelligence data shows.
The board expects to hold an additional hearing on the matter. A comment period of at least 45 days will start once the proposal is published in the Illinois Register. (Illinois Pollution Control Board Case No. R18-20)