Background

Foth was retained by the United States Army Corps of Engineers (Corps) of Rock Island District to characterize sediment within a 12-mile stretch of the Calumet-Sag Channel, located in Cook County, Illinois. Multiple municipalities use this channel and multiple industries and municipalities rely upon underground utilities within the channel. Known chemical and biological hazards were potentially affecting the local environmental quality within the project area.

Approach

Foth designed and implemented a sampling plan, which included the collection of representative sediment samples for bulk characterization, as well as the collection of sediment for Modified Elutriate Testing. The data from the analyses is being used to design a dredge plan and site and design a Confined Disposal Facility (CDF). Foth coordinated with industries and municipalities on channel usage and utility locates.  Sediment cores were collected over the full depth of the proposed dredge prism in areas with potential chemical and biological hazards. Foth processed the cores on-site and chemically analyzed select samples using a mobile laboratory.

Results

The elutriate sample analyses were designed in a staged approach  to optimize data and reduce laboratory costs. Representative samples were obtained throughout the expected dredge prism in less than four days using Foth’s Vibracore™ rig with DGPS navigation system, and subjected to extensive chemical, geotechnical and elutriate testing. Foth compiled historic sediment data into a comprehensive report that evaluated the data for spatial and temporal trends. We assisted the Corps with negotiations on applicable Illinois Environmental Protection Agency regulations and permits that will be required for dredging and disposal. Additionally, Foth developed design criteria for reuse of an existing CDF as well as siting/design criteria for an undetermined new CDF.