DECATUR — A big dig will soon be under way to rid Decatur of the last traces of something that was once its civic pride and joy: a manufactured gas plant that kept the lights on and provided gas for heat and cooking in the Victorian age.
The buildings are long gone from the 3½-acre site next to the electrical substation at 515 E. Main St., but chemical residue, including a substance called coal tar that can pose cancer risks with long-term exposure, are trapped in the ground and need to come out.
Removing some 90,000 tons of that dirt and cleaning up the site will cost $14 million and take 18 months. The project’s most visible sign so far is the erection of a vast white tent that uses a closed-air system to stop contaminated dust from blowing around. The removed soil will be trucked to a Macon County landfill licensed to receive and dispose of it.
An in-depth report by utility Ameren Illinois, which is carrying out the work, states groundwater on the site has been “impacted” by the contaminated soil. But Ameren and experts from the Illinois Environmental Protection Agency monitoring the cleanup say the water is not used by anyone and is not part of the city water supply.
An public open house to explain the project and take questions will be held on site 4 to 7 p.m. Tuesday.
The soil removal will generate 15 semitruck trips per day on a Monday through Thursday work week running from about 7 a.m. to 3:30 p.m. Ameren Illinois says its working with the city of Decatur to limit traffic inconvenience.
“We don’t expect very much disruption at all,” said Brian Martin, the consulting environmental scientist overseeing the project for the utility. “We’ll maybe have to stop traffic a couple of minutes when a truck comes out onto the road.”
Martin said the history of the Decatur manufactured gas plant dates to 1865, when it was built by the Decatur Gas Light & Coke Co. “I’ve worked on a lot of these projects, and the history is just fascinating,” Martin added. “At the time, these facilities were a great source of civic pride and getting one would be comparable to a town getting broadband Internet today.”
The widespread availability of cleaner natural gas has made cooking gas from coal obsolete.
Ameren Illinois inherited control of 44 contaminated old plant sites, and 16 remain to be cleaned up. The bill so far has come to $250 million, and the utility expects to spend another $260 million dealing with the rest.