Earlier, Joliet, Will County, Lockport and Rockdale have already given approval for the coal-fired electrical plants’ entry into the zone, reports Sun-Times.

The two coal-fired power stations are at 1800 Channahon Road in Joliet and 529 E. 135th St. in unincorporated Romeoville, Illinois.

Village Administrator Steve Gulden was quoted by the news paper as saying that the zone was created in 1983 to attract investment and encourage development in Will County.

Gulden added that Romeoville joined the zone in 1989 and the village would not be making final approval of Midwest’s planned environmental upgrades to its two facilities.

The planned upgrades call for about $100m in investment in the two plants and several hundred jobs during the upgrade period.

Mayor John Noak remarked about the impact of the investment on over 400 families with employees working at the plants.

"Ultimately all of those jobs are at stake if the generation plant is not able to get its upgrades where it needs to be with the state," Noak.