With their first conclusive report in 2004, two University of Illinois professors have been working to develop a way to successfully cover landfills.

Timothy Stark, University professor in civil and environmental engineering, and Krishna Reddy, associate professor of civil and material engineering at the University of Illinois at Chicago, has been working together to solve two major landfill issues.

“We were faced with two problems,” Reddy said in a telephone interview. “First, the problem with the disposal of scrap tires and second, with the need for final covering on many abandoned landfills. When faced with these two problems, we figured why not solve them both at once.”

The disposal of tires is a major issue because they pile up over the years and create several problems for landfills. Besides being tough on the eyes, they are home to many mosquitoes as well as the production of hazardous gases such as methane, Reddy said.

“Using tires for landfill cover leads to fewer expenses on top of solving the issue of conserving other valuable materials,” Stark said.

According to the official experiment report, the duo went about testing their idea by comparing data they collected on tire shreds to data on sand and gravel, two materials generally used to cover landfills. They started by trying many different sizes of tire shreds, but found that a piece measuring roughly 4 inches by 6 inches in size would produce the best results.

“Our data showed that shredded tires are definitely comparable, if not better than, other materials used to currently cover landfills,” Stark said.

“With this new information, we found that shredded tires are about three times more permeable than sand or gravel,” Reddy added.

However, this project could not be solved by only testing products in the lab. Reddy and Stark tested their tire experiment at different locations around Illinois to understand large-scale effects.

“We were able to test in two sites, one was in Southern Illinois and the other in South Chicago,” Stark said.

Still, testing and performing on such a large scale requires thousands of tires.

“We wanted to make sure that we were actually cutting down the amount of tires in landfills,” Reddy said. “A playground can use tire shreds, but only in small quantities; where as, a landfill needs about 70,000 tires to cover one acre.”

The conclusion of their experiments shows a major benefit for cutting down pollution. The next phase is to make people aware that this alternative is out there, they said.

“We are planning to make a lot of people aware of this,” Reddy said. “We are already receiving plenty of questions from people interested in learning more.”

“One particular landfill operator has contacted me about saving money and space through our research,” Stark added.

In order to research and fund the experiment, the group received support from the Illinois Department of Commerce and Economic Opportunity.

“Whenever you go to get your tires changed, you are charged an extra dollar or two,” Stark said. “This extra funding goes to disposal of tires. That is where we gained money to take on this project.”

The main aspect of these tests focuses on a major pollution issue in the country.

Carla C ceres, University assistant professor of animal biology, feels that this project will benefit our society by cutting down on groundwater pollution.

“Since the early 1990s, landfills have been required to control hazardous waste,” C ceres said. “The reason they need to control the hazardous waste is because if the landfill is not protected properly, it can contribute to serious groundwater pollution.”

The pollution of groundwater is a major problem in several parts of the United States.

“Once groundwater becomes polluted, it is extremely difficult to clean up,” C ceres added. “It is better to prevent the pollution in the first place.”