The plants are not far from each other in the city's Pilsen and Little Village communities. The same company owns both plants.
It was the first all-steam turbine station in the nation when it opened 108 years ago. The Fisk Generating Station and the 84-year-old Crawford power plant - both coal-fired electricity makers - have been modernized over the years, but not to the satisfaction of many environmentalists and residents who live in the shadow of their smokestacks.
"It's the fact that we have such a high rate of asthma in our neighborhood and we have such a high rate of breathing and respiratory issues in our neighborhood," said Kimberly Wasserman, Little Village Environmental Justice Organization
"Either install modern pollution control equipment and clean up these old plants or shut them down," said Howard Learner, Environmental Law and Policy Center.
The fight has been under way for years, with critics citing medical studies that attribute premature deaths, heart attacks, and respiratory diseases to the soot and chemicals that Fisk and Crawford put in the air.
"The fact of the matter is we've been cleaning up progressively and continuously since we got here in 1999," said Douglas McFarlan, senior VP, Midwest Generation.
Midwest Generation bought the two plants from ComEd 11 years ago. It has added more pollution controls, and five years ago it reached an agreement with the state on a timetable to further reduce certain types of pollution.
But critics say the timetable is too broad and controls too lenient.
"For ten long months we have waited for a hearing, and for ten long months we have not had a hearing," said Alderman Joe Moore, 49th Ward.
Moore is the chief sponsor of the Chicago Clean Power ordinance which would require both plants to dramatically reduce their particulate matter and Carbon Dioxide emissions.
Moore held his own hearing Monday. He does not now have the votes to pass it.
"The state of Illinois regulations that we have are every bit as tough or tougher than federal regulations, and we vigorously oppose the city of Chicago piling on top of that with their own ordinance because, frankly, it's just no necessary," said McFarlan.
Midwest Generation says the measurable pollution around Fisk and Crawford come from a variety of sources, the plants are just a fraction of that, and that the opposition is all about killing coal as an energy source.
Moore says public health suggests otherwise.
"We owe it to this generation and future generations to once and for all clean those power plants up," said Moore.
Moore says he has 16 votes lined up. He needs ten more to pass his ordinance. A similar measure sponsored by powerful alderman Ed Burke failed nine years ago. Moore believes that this is a different time with a political climate that is changing - new mayor, new council, new dynamic.
Midwest Generation contends it's really about getting rid of coal, which it says is an ill-advised move because coal accounts for roughly half of the electricity generation in the U.S. today.