Dive Brief:

• The Illinois Pollution Control Board (IPCB) on Thursday modified a proposal to change the accounting method for emissions rules covering eight power plants, seeking middle ground in a fight between environmentalists and Vistra Energy.
• Vistra, formerly Dynegy, owns eight coal plants in downstate Illinois and has asked for changes to the methods regulators use to measure whether the plants are in compliance in order to make the plants more competitive in wholesale power markets.
• Sierra Club and other conservation groups argued the changes could actually lead to more pollution. Illinois One reports the IPCB's move this week essentially "punts" the decision to the next governor's administration, because regulators opted to begin the public review again.

Dive Insight:

The board agreed with the generator's proposal to consider total emissions, but opted for a lower annual cap on the coal plant emissions than Vistra wanted.

Vistra had asked regulators to use a system that would consider the total emissions from the plants and put in place a fixed cap. That system could have actually allowed Vistra to shutter the cleaner plants and run the older ones, ultimately raising emissions, according to Sierra Club and the Union of Concerned Scientists.

Under current rules, the generator has to run its cleanest — and more expensive — plants to balance out the emissions from older facilities.

The IPCB's decision tries to find middle ground between the groups. Regulators also required the cap be reduced when plants are retired, mothballed or sold.

Sierra Club in a statement said the decision represents progress, but the group still has concerns. 

"These important revisions to IEPA's proposal reflect the input of thousands of individual testimonies, and reject Dynegy-Vistra's request that would have allowed it to close some plants while running cheaper, dirtier plants," Sierra Club said in a statement. 

Environmentalists warn the new proposal could still lead to increases in pollution over the original standard. But Sierra Club said "advocate groups see this as a move in the right direction but raise concerns from communities impacted by pollution from Dynegy-Vistra coal plants."

Vistra officials are "still reviewing the order and don't have a comment at this time," a company spokesperson said.