Boulder County’s planning office has reversed its 2024 termination of the controversial Lyons CEMEX cement plant’s right to operate, throwing a lifeline to one of Colorado’s three cement manufacturers while infuriating neighbors and environmental advocates who thought they’d won a long-running closure battle.
Boulder County Community Planning and Permitting Director Dale Case on Tuesday rescinded a previous county notice of termination to CEMEX, saying that previous studies had overstated truck traffic to and from the plant on Colorado 66. The county’s 2024 termination had ruled that increases in CEMEX traffic violated nonconforming use provisions in its land use permit.
“The evidence shows that there was no significant increase in truck traffic to and from the property since the closure” of the CEMEX Dowe Flats materials quarry across the highway in 2022, compared with a traffic study from 1994, the planning office’s reversal said.
Neighbor and environmental advocates who have pushed to get rid of CEMEX for years said they are considering their next administrative or legal options in opposing the kiln’s operations.
“We are deeply disappointed by Boulder County’s reversal. This decision reads like Boulder County treated inconvenient facts as obstacles to get around rather than evidence it had to confront,” said Sarah Lorang, who has helped organize neighborhood opposition to CEMEX in the Lyons area.
“A reversal this consequential should not be allowed to rest on an undisclosed traffic study and a conclusion that appears to ignore the central facts in the record,” Lorang said.
The CEMEX kiln is “old, falling apart, and poses an ever-growing threat to public health and the environment in the region,” said Jeremy Nichols, with the nonprofit Center for Biological Diversity. “The plant continues to have trouble complying with its air pollution permit at all times, notwithstanding ongoing state efforts to enforce rules. It’s disappointing to hear Boulder County completely reversed themselves. There was some hope that by putting the writing on the wall, the county could negotiate a reasonable outcome.”
CEMEX has long operated one of only three cement kilns in Colorado at the location surrounded by Boulder County and Lyons open space. The plant is a big target of environmental groups for pumping out about 300,000 tons of greenhouse gases a year, one of the largest single sources in the state, and for repeatedly violating state rules on controlling dust and other local pollutants from the site.
After Lorang made her statement Wednesday, Boulder County amended its news release to include its most recent, independently commissioned traffic evaluation. The study is not based on new traffic data, but is a meta-analysis of the reliability of three previous traffic studies including one commissioned by CEMEX itself.
Case said in an interview Wednesday the county’s decision had to be made based on what traffic was allowed under the nonconforming use conditions in the 1990s, and whether current traffic is a major increase from those allowed levels.
“That means we have to look at that whole history,” Case said.
“When we look at the history of the site and the traffic overall, it was fairly similar to what it had previously been in a lot of ways, so not something that we can look at as an alteration,” he said.
CEMEX offered Boulder County officials a deal in 2022: If the county approved an extension for the mine operating permit across the highway from the kiln, the company would donate about 1,000 acres of open space for local parks and agree to close the mine and the kiln within 15 years. Dowe Flats produced limestone and shale for use in cement making; for some years the material was delivered across the highway to the kiln via an overhead conveyor.
After months of public comment and deliberation, the county commissioners declined to renew the mining permit, and Dowe Flats shut down. The kiln continues to operate and increased trucking of cement-making materials from outside the area.
Since then, state air pollution officials announced two consent agreements with CEMEX to settle ongoing violations of its air pollution permits, with one fine hitting $1.3 million. The neighborhood activists pointed to what they said was newly increased truck traffic after the mine closure as evidence the kiln site was violating its land use permits and should be shut down entirely.
CEMEX formally appealed the county’s 2024 termination notice and continued to operate during the administrative reviews.
“CEMEX appreciates the Boulder County Planning Director’s decision to rescind the prior determination regarding our Lyons cement plant, affirming our compliance with the County land use code. Cemex is proud to operate in Colorado,” said CEMEX communications and marketing director Randy Stuart.