Environmental Progress - Fall 2003

Coal Tar Cleanup Underway at Canton

Fulton County cleanup includes diverting nearby creek temporarily

For decades in the late 1800s and early 1900s, many Illinois communities relied on coal gas, locally manufactured, to provide municipal and residential lighting in much the way natural gas is used today.

From 1878 until 1934, coal gas was produced in Canton in Fulton County. The production process involved the slow burning of coal and often left behind coal tar contamination that includes many of the same chemicals found in most petroleum products. Coal tar is considered a possible carcinogen and utilities are cleaning up many sites of this type across the state.

At the 1.4-acre site in Canton, coal tar contaminated both the area soils and the sediments of Big Creek. Because of the involvement of a waterway, a creative method had to be developed to remove the contaminated sediments. Coal tar is present in significant quantities in both the site soils and the creek sediments near the Route 9 bridge.

Stream rerouted for 300 feet

AmerenCIPS, the party responsible for cleaning up the Canton site, proposed a Remedial Action Plan for IEPA approval. The proposal included temporarily rerouting Big Creek, as well as erecting a "Sprung© structure" over the work area to contain any contaminants that might become airborne during the excavation of the soils. Rerouting Big Creek required approval by the U.S. Army Corps of Engineers as well.

At the start of the project, dams were located both upstream and downstream of the project site, then pumps were installed ahead of the upstream dam. The water was pumped approximately 300 feet, then discharged below the downstream dam. Pumps were also installed between the dams, to dewater the work area so the contaminated soils can be removed.

Once the excavation of soils is completed, and contaminated soils are removed and properly disposed of, the Sprung structure will be removed and the creek flow will be returned to its normal path. In the creek channel, soils will be excavated to bedrock - approximately 8 to 12 feet - to ensure that all contaminants are removed.

In response to a recommendation by the Corps, contractors will remove old bridge pilings and foundations dating back more than a century, and replace the materials with riprap to provide a more habitable environment for wildlife around the creek.