After a delay of more than a year, state air-quality regulators have begun reviewing the application from Grupo Cementos de Chihuahua (GCC) to burn old tires to heat the kiln at the cement plant south of Pueblo, Colrado.

Colorado Department of Public Health and Environment officials said they will probably issue a draft permit in mid-December for public comment, which could include a public hearing if requested. If regulators don’t find problems with the GCC plan, the cement maker could receive its tyre-fuel permit as early as next February.

GCC is licensed to burn coal in its kiln and the plan it submitted to the health department in 2010 asks to add processed old tires to the fuel. The Mexico-based cement maker purchased a tire disposal field near Midway in 2009.

Martha Rudolph, director of environmental programs for the state department said the long wait on the GCC applications was due to a shortage of expert "modelers" at the state health department, scientists who can review an air-permit application and its supporting analysis.

"There has been a bottleneck for some time but we’re now looking at the GCC application," Rudolph said.

Gina Nance, manager of the GCC plant, said the plant is running at about 60 per cent of capacity.

"It’s going to require about $2 million in improvements at the plant to use the tyre-derived fuel," she said.

"Not only are tyres cheaper to burn than coal, but we’ll also be getting rid of all those old tyres (at Midway)."