10 July 2003

Results from emissions tests and air dispersion modeling around the CEMEX cement plant just east of Lyons indicate that there is "no public health hazard" connected with burning tires as an adjunct fuel at the plant.

CEMEX announced just over a year ago that it wished to resume burning up to a 20 percent tire mix with the coal it now burns in the kiln process used in making cement. CEMEX has a special use permit from Boulder County and an air pollution control permit issued by the Colorado Department of Public Health and Environment (CDPHE) to operate the quarry and cement plant. Both of these permits allow burning tires as a supplemental fuel.

In November, 2002, CEMEX conducted a "stack test" whereby emissions created by burning coal only were measured against a mix of coal and 19% tires (also know as tire derived fuel). 
Those test results were reviewed by Boulder County Public Health who asked the Agency for Toxic Substances and Disease Registry (ATSDR) - an agency of the U.S. Department of Health and Human Services - to perform a thorough evaluation of the potential health impacts resulting from stack emissions from the CEMEX Lyons plant.

Working with CDPHE, ATSDR used air dispersion modeling to determine what the ground-level concentrations would be of the emissions released from the stack.

This evaluation, also called a health consultation, determined that at the maximum human exposure possible, none of the stack emissions exceeded health guidelines and regulatory standards. In most cases, the ground-level concentrations were several orders of magnitude below the health guidelines and standards.

For this reason, ATSDR classified stack emissions at the CEMEX plant as posing "no public health hazard."

Boulder County Public Health plans to hold a public meeting in the Lyons area to review the findings of the health consultation with community members. CDPHE has approved the air quality emissions test and the use of tires, as long as the percentage of tires burned does not exceed the amount used in the stack test.

Based on the recent decision by Boulder County Land Use Director Graham Billingsley that the existing Special Use Permit is still in effect, CEMEX could technically begin burning tires today. 
However, the cement company is awaiting a decision from Boulder District Court Chief Justice Roxanne Bailin as to whether or not the previous special use permit issued by Boulder County in 1989 is still in effect. 

The Sierra Club, along with concerned citizens in the Lyons area, filed suit in district court earlier this year contesting the validity of the special use permit, arguing that it had lapsed because the cement plant ceased burning tires in 1993. A hearing on the matter by the Board of Adjustment will be held in August or September.