Cemex officials this week are testing how burning tires as fuel at their Kosmos cement plant in southwestern Louisville affects air quality.

If it can be shown that burning tires improves emissions, company officials said they would consider using tires for up to 25 per cent of the plant’s cement kiln fuel, along with coal and petroleum coke.

The plant on Dixie Highway could potentially burn between 2Mt and 3Mt tires annually and take up much of the region’s illegally dumped used tires, said Jennifer Borgen, a Cemex spokeswoman.

On Monday, The Courier-Journal reported that solid-waste officials in Kentucky were having difficulty keeping up with an endless stream of used tires, many of which are illegally dumped.

“It’s (potentially) a win for the environment,” Borgen said of the company’s plans. Any ash from the tires becomes part of the cement, so there’s no waste product, she said.

But Borgen said it’s too soon to say whether Cemex will proceed with the plan, which it unveiled in 2006. Officials need to complete the tests, analyze the results, and brief air-quality regulators and residents, she said.

The company is also checking to see whether the new fuel affects the quality of the cement.