The proposal by Rauner was intended to help a struggling industry.
The proposed amendments to the state rules would have affected eight plants operated in central and southern Illinois by Texas-based Vistra Energy. The changes would have replaced the rate-based limits with annual caps on tons of sulfur dioxide and nitrogen oxide emitted by the plants.
Spokeswomen for Vistra and the Rauner-led Illinois Environmental Protection Agency declined comment on Thursday’s ruling.
Howard Learner of the nonprofit Environmental Law and Policy Center says Rauner’s proposal would have allowed Vistra to “burn more coal at its dirtiest, cheapest plants in Illinois and put public health and the environment at risk.”