• Original Reporting
  • Sources Cited
Original Reporting This article contains new, firsthand information uncovered by its reporter(s). This includes directly interviewing sources and research / analysis of primary source documents.
Sources Cited As a news piece, this article cites verifiable, third-party sources which have all been thoroughly fact-checked and deemed credible by the Newsroom in accordance with the Civil Constitution.
Cemex’s Cement Plant on June 13, 2022, near Lyons. (Hugh Carey, The Colorado Sun)

The Boulder County Commissioners Thursday voted against a deal that would have extended a mining permit for Cemex near Lyons in exchange for closing a high-emissions cement plant in 15 years and 1,000 acres of open space, after a groundswell of public opposition doomed the staff-negotiated agreement. 

The commissioners voted 2 to 1 against the deal.

Cemex officials at the last minute offered to end cement making at the Lyons plant 12 years from now instead of the 15 years agreed to in the initial proposal with Boulder County staff. The company also said it would commit to cutting greenhouse gas emissions by 5% a year starting now, rather than in 2025 when new state laws for heavy industry will require audits and emissions cuts. Cemex said it would make the 5% cuts by purchasing carbon offsets amounting to 17,000 tons of its annual emissions, beginning Jan. 1. 

The new concessions, combined with previous commitments to work with regulators on dust control and best available greenhouse gas technology, “strike the right balance” for an agreement, Cemex Vice President Trpimir Renic told the commissioners before their vote. 

The county commissioners’ final action came after the Boulder County Planning Commission recommended against a complex agreement worked out between Cemex and Boulder County Parks and Open Space. The Cemex permit for mining cement-making materials expires this fall; the cement-making plant on the south side of the highway, attached by a conveyor belt to the Dowe Flats quarry north of Colorado 66, can operate indefinitely under state air pollution permitting. The plant, one of the larger polluters in the state, pumps out more than 350,000 tons of carbon dioxide in an average year. 

If the county issued a 15-year mining permit, Cemex agreed to shutter the cement plant in 2037. Cemex also offered to give up about 1,000 acres of open space to the county for free, and more acres at a sharply reduced price. 

Cemex is adamant that it will continue to operate the much-criticized cement plant indefinitely even if it doesn’t get a mining extension, by trucking in more cement-making materials from long distance.

Opponents wanted county officials to call Cemex’s bluff, arguing the company is likely to close the plant without the next-door materials. They also claim trucking in large amounts of outside materials would require revisions to Cemex’s other state and local permits, giving county officials another chance to seek more concessions.

The Daily Sun-Up podcast | More episodes

The commissioners said they were struggling to balance the opposition from neighbors and community advocates with the actual question in front of them, which was just about extending the mining permit and whether its continued operations were compatible with land use rules. 

Commissioner Claire Levy said mining was not meant to be “perpetual” at Dowe Flats, and that the county had the right to change or stop the permit if land use requirements and public needs changed. She also said she was very concerned about the ongoing greenhouse gas emissions from the cement plant, and that it was time for the entire area to start land reclamation. 

Commissioner Matt Jones disagreed, saying the switch to 12 years from 15 for the agreement helped sway his opinion. With the chance to have a deal to close both the mine and the high-emissions cement plant in 12 years, “we shouldn’t pass it up,” Jones said.

“This county will never have the chance to acquire that much open space again,” Jones argued.

Commissioner Marta Loachamin praised Cemex for pledging to move to lower-carbon cement production at the plant. But she said the commitments the company has made are not enough to offset continuing impacts of mining north of Colorado 66. 


It’s not clear at all that Cemex will end up closing the cement plant on its own if the mine does not receive an extension, Jones added, despite public claims. With Colorado’s continuing growth, estimated to hit 9 million people in coming decades, local demand for cement will stay strong and push Cemex to keep the Lyons operation going even without local shale, he said.

Loachamin and Levy voted to deny the permit, while Jones voted to extend it and take the accompanying deal.

Some of the Lyons neighbors who organized opposition to the bargain rejoiced after Thursday afternoon’s vote. They also indicated they may now seek new restrictions on the cement plant, though its main air pollution operating permit comes through the state Air Pollution Control Division.

“We applaud the commissioners for their courage and intelligence in face of the climate crisis,” said Bart Lorang, who made detailed arguments against the Cemex operations along with his wife, Sarah, and other neighbors. “Now, we urge Boulder County to conduct a full and thorough formal review of the nonconforming status of the cement plant.” 

Planning commissioners had also agonized over the proposal, with many hoping for shorter permit lengths from Cemex in a renewed round of negotiations. Fifteen years is too long, they said, for both neighbors suffering from dust and pollutants, and for Boulder County’s ambitious goals to cut greenhouse gas emissions in the climate change battle. The deal’s objectors say Cemex is the largest single source of greenhouse gas emissions in Boulder County.

Other planning commissioners were worried, though, that they were rejecting the best deal the county was going to get from international giant Cemex. 

The county commissioners vote came on a day when they did not take public testimony from either side about the deal. They did listen to hours of public comments from opponents, from Cemex leadership, and from some Cemex employees during a seven-hour Sept. 14 commission hearing. 

Michael Booth

Michael Booth is a Colorado Sun reporter covering health, health policy and the environment. Email: Twitter: @MBoothDenver