Joshua Handley, of Envirocon and Operators Local 150, carries a section of piping that will be used to pump bentonite clay mixture into a slurry wall trench at the Ralston Street Lagoon (background) site in Gary, Ind. Wednesday June 6, 2012. Remediation work is continuing at the site located between the Indiana Toll Road and the Gary/Chicago International Airport. | Stephanie Dowell~Sun-Times Media

Envirocon works assemble a long-stick excavator at the Ralston Street Lagoon site in Gary, Ind. Wednesday June 6, 2012. Remediation work is continuing at the site located between the Indiana Toll Road and the Gary/Chicago International Airport. | Stephanie Dowell~Sun-Times Media

A long-stick excavator is assembled at the Ralston Street Lagoon site in Gary, Ind. Wednesday June 6, 2012. Remediation work is continuing at the site located between the Indiana Toll Road and the Gary/Chicago International Airport. | Stephanie Dowell~Sun-Times Media

Traffic on the westbound Indiana Toll Road (left) passes by the Ralston Street Lagoon site in Gary, Ind. Wednesday June 6, 2012. Remediation work is continuing at the site located between the Indiana Toll Road and the Gary/Chicago International Airport. Stakes bordering the lagoon will be the center of the new slurry trench being created to prevent toxic sludge from leaving the lagoon area. | Stephanie Dowell~Sun-Times Media

Joshua Handley, of Envirocon and Operators Local 150, displays a handful of bentonite at the Ralston Street Lagoon site in Gary, Ind. Wednesday June 6, 2012. Remediation work is continuing at the site located between the Indiana Toll Road and the Gary/Chicago International Airport. The bentonite will be mixed and used for the slurry wall. | Stephanie Dowell~Sun-Times Media

Bags of bentonite clay wait to be used for the slurry wall at the Ralston Street Lagoon site in Gary, Ind. Wednesday June 6, 2012. Remediation work is continuing at the site located between the Indiana Toll Road and the Gary/Chicago International Airport. | Stephanie Dowell~Sun-Times Media

Remediation work is continuing at the Ralston Street Lagoon site in Gary, Ind. Wednesday June 6, 2012. The site is located between the Indiana Toll Road and the Gary/Chicago International Airport. | Stephanie Dowell~Sun-Times Media

An excavator rests on a temporary barge near a small boat used to measure depths and set work zones at the Ralston Street Lagoon site in Gary, Ind. Wednesday June 6, 2012. Remediation work is continuing at the site located between the Indiana Toll Road and the Gary/Chicago International Airport. | Stephanie Dowell~Sun-Times Media