The CEMEX Appeal, Explained
What this is about
CEMEX's Lyons plant is "grandfathered." It was built before the current rules, so it's allowed to keep operating under what's called a nonconforming use. The condition is that it can't significantly expand or intensify what it did when the rules changed. If it does, it can lose that status and has to meet today's standards.
When CEMEX's Dowe Flats quarry closed in September 2022, the plant stopped getting its limestone by conveyor and began trucking it in from Wyoming and Golden. Truck traffic on Highway 66 jumped in a small community that had seen almost none for decades.
What the County first decided
In April 2024, after reviewing the evidence, Boulder County's Planning Director agreed with us. CEMEX had intensified its operations enough to lose its nonconforming status, and the County issued a notice of termination.
The rescission
On May 19, 2026, the County reversed itself and rescinded that notice, eight days after the State of Colorado fined CEMEX $855,000 for air quality violations.
The entire merits finding was one sentence: the evidence shows no significant increase in truck traffic since Dowe Flats closed, compared with 1994.
That sentence doesn't match the County's own file. The 1994 data shows about 37 average daily truck trips. CEMEX's own 2023 traffic study shows about 303. That's more than seven times as many, and we believe the real number is higher.
The County's Land Use Code puts the burden of proof on CEMEX to show that its operations haven't changed. The County's decision doesn't explain how CEMEX did that, and our attorney called the reversal legally perplexing. We agree.
Why we appealed
We appealed to the Boulder County Board of Adjustment because the decision rests on facts the record contradicts, and because the deadline to challenge it is short. If we don't appeal, the rescission stands, and CEMEX would effectively have permission to operate at its current level indefinitely.
The hearing is currently set for November 4, 2026.
What you can do
Our work has been funded largely by a small group of neighbors, and the legal path ahead is long. You can also join our mailing list for updates and calls to action, or donate to the appeal fund through Save Our Saint Vrain Valley. Click Here to Donate
Want to dig a little deeper? We’ve made all of our research (all the permits, studies, and county records) open-sourced and public here: https://github.com/lorangb/cemex-nonconforming
Point your favorite AI tool at the repo and interrogate the facts yourself.
