Boulder County sent a letter today to Cemex terminating the company’s right to operate its cement plant east of Lyons, citing a traffic study that shows increased traffic created a hazard and expanded the use of the plant at 5134 Colo. 66, Longmont.
Boulder County Community Planning and Permitting Director Dale Case said in a news release that the letter tells Cemex to stop operating.
“After a thorough investigation, we have determined that additional traffic at the plant has expanded Cemex operations,” he said in the release, adding an expansion isn’t allowed under the county’s land use rules.
Cemex has 30 days to provide evidence that the director’s determination was incorrect, reduce the cement plant’s use or appeal to the Boulder County commissioners, according to the county. Cemex will be able to operate its cement plant under current operating conditions until a final determination is made.
Cemex officials couldn’t immediately be reached for comment.
The plant has operated outside Lyons since 1965, according to the county. In 1994, Boulder County amended its land use code to require special use approval for those types of operations and the cement plant became a nonconforming use. Under the code, nonconforming uses are allowed to continue, but generally can’t be expanded.
The Boulder County commissioners in 2022 denied Cemex’s application to continue mining at the Dowe Flats Quarry east of Lyons for 15 more years. The county had authorized Cemex in 1994 to mine the quarry for a maximum 25-year period.
After the Dowe Flats Quarry closed, the county began receiving complaints from area residents that the use of the cement plant had intensified, including increased truck traffic, according to county officials. Along with complaints about traffic, residents have raised concerns about air pollution.
Following the complaints, the Colorado Department of Transportation required Cemex to conduct a traffic study. The study demonstrated a more intensive level of truck traffic at the cement plant since the closure of the Dowe Flats Quarry, according to the county.
As a result of the study, the state determined that vehicles could no longer turn left from the cement plant’s drive onto Colo. 66. CDOT likely will require Cemex to make alterations to prevent this left turn, according to the county.
Reviewing the traffic study and other information, Case determined the additional traffic has created a hazard and intensified the use of the Cemex property.
While the quarry was operated, he said, the county recorded about 600 average daily trips at the plant. A traffic study last year found that number more than doubled, to an average of 1,283 daily trips.
“Daily trips are one of those thresholds that are key to how we regulate land use in the county,” he said. “It’s important that companies are held to those standards.”
One group that has complained to the county and urged the plant to shut down is Good Neighbors of Lyons. The resident advocacy group requested a hearing in January as part of the Colorado Air Quality Control Commission’s permit process. At the hearing, the group requested stricter monitoring of the plant’s emissions.
A global building materials company, Cemex operates 10 cement plants and about 50 cement terminals across its U.S. network, which extends to Boulder County.
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