The owner of the DeKalb County Landfill must provide information demonstrating that operations will not pollute the ground water before the county will approve his request for expansion.

In a hearing Friday, the DeKalb County Board’s Landfill Committee expressed concern that expansion of the landfill will contaminate the ground water from the seepage of leachate into the soil. Leachate is a combination of rainwater mixed with residue from the landfill’s garbage.

Landfill owner Rodney Engstrom is seeking to expand the 38-acre site, located on Somonauk Road near Cortland, by a 45-foot height increase and a 26-acre width increase.

The committee postponed a decision about the landfill, and the hearings will continue on March 31.

The committee asked Engstrom to provide additional data about the leachate collection system. Also requested was information about the type of liner in the existing landfill. The liner separates the landfill’s garbage from the soil.

In addition, the committee asked Engstrom to provide ground water monitoring data for all wells surrounding the landfill and to analyze samples of drinking water from those wells.

He also must redrill soil borings to a depth of 30 feet below the bottom of the landfill and provide soil borings from the existing site. Finally, he must supply information about the ground water flow.

Greg Kugler, an engineer at Andrews Engineering in Springfield who represents Engstrom, testified before the committee that the contaminants found in samples were naturally occurring and might not have resulted from the landfill.

This testimony was in response to information given last week by Gerald DeMers, an engineer with Graef, Anhalt and Schloemer of Milwaukee, who had testified that heavy doses of six metals were found in wells near the landfill. These metals include chromium, silver, mercury, cadmium, lead and selenium.

At that same hearing, Joan Muraro, Springfield public water specialist for the Illinois Environmental Protection Agency, said these contaminants are not present in the area’s drinking water.

Also, on March 9, 1988, Tom Henninger of the IEPA inspected the landfill and cited it for uncovered refuse, inadequate daily cover and litter violations.

Engstrom estimates the existing landfill will be filled to capacity by summer. However, it is unlikely the application to expand the landfill will be approved by both the DeKalb County Board and the IEPA by that time, DeMers said.