Changes to an important state air pollution standard are being considered by the Illinois Pollution Control Board this summer. My colleagues and I found striking differences among the Dynegy plants that would be affected by the proposed rule change to be decided on as soon as Thursday August 23. Under the current Illinois Multi-Pollutant Standard (MPS), the Dynegy coal plants that cause the most harm to Illinois residents are the ones more likely to be closed or be upgraded with air pollution control technology. But if the Pollution Control Board adopts Dynegy’s proposal to change how state air pollution limits are calculated, it could result in the company closing its cleaner plants and keeping its dirtiest plants open because it would no longer need the cleanest plants in its fleet to comply with the state requirements. My colleague James Gignac, lead analyst in the Midwest Climate and Energy Program at the Union of Concerned Scientists (UCS), further reflects on the impacts of the proposed change to the MPS, below. Read more >