Quick Background

Background

  • The CEMEX Lyons Cement Plant was originally constructed in 1969, well before Boulder County adopted its Land Use Code in 1994 — granting it grandfathered, or "nonconforming," status that allowed it to keep operating under the old rules.

  • Also in 1994, CEMEX opened the Dowe Flats quarry adjacent to the plant, extracting limestone and shale for over 25 years. To minimize truck traffic on Highway 66, CEMEX was required as a condition of the quarry's Special Use Permit to transport those materials via an enclosed conveyor belt across the highway. For 25 years, that conveyor meant virtually no raw material trucks on the road.

  • In 1997–1999, the plant underwent a significant $10.3 million expansion that drew legal scrutiny and resulted in an EPA lawsuit over environmental violations.

  • In 2022, CEMEX applied to extend its Dowe Flats mining permit for an additional 15 years. The Boulder County Board of Commissioners denied that application on September 29, 2022. With the quarry closed and the conveyor decommissioned, CEMEX shifted to trucking 100% of its raw limestone and shale from a quarry in Wyoming — roughly 250 miles away — more than doubling truck traffic on Highway 66 almost overnight.

  • After a year-long investigation, Boulder County's Planning Director issued a Notice of Termination of CEMEX's nonconforming status on April 10, 2024, finding that CEMEX had violated the Land Use Code by dramatically intensifying its operations. The Code provides that any "enlargement or alteration of the nonconforming use which has the effect or threatened effect of creating a hazard or nuisance on or off the property, of adversely affecting the character of the neighborhood, or of intensifying the use of the land or its need for services" warrants termination. It further states that the County has a duty to eliminate nonconformity "as speedily as justice will permit."

  • CEMEX challenged the termination. The County conducted an extended review, during which it commissioned an independent traffic study by Stolfus & Associates — its own hired expert — which confirmed that truck volume had increased 118% while cement production grew just 6%.

  • On May 19, 2026, the Planning Director reversed his own determination in a three-page letter whose entire merits finding was a single sentence: "The evidence shows that there was no significant increase in truck traffic to and from the property since the closure of the Dowe Flats quarry, compared with 1994 traffic." By CEMEX's own traffic study, truck trips had increased more than 700% compared to actual 1994 levels. Good Neighbors of Lyons and Save Our Saint Vrain Valley filed an appeal with the Boulder County Board of Adjustment before the June 18, 2026 deadline. A public hearing will follow. We are not done.

Click Here For a More Detailed Timeline

Compliance Investigation Highlights

Boulder County Community Planning and Permitting: Case ZON-23-0003

Per the Boulder County Land Use Code, “The right to continue a nonconforming use terminates immediately when [there] is any other enlargement or alteration of the nonconforming use which has the effect or threatened effect of creating a hazard or nuisance on or off the property, of adversely affecting the character of the neighborhood, or of intensifying the use of the land or its need for services.” 

  • CEMEX was issued a Notice of Termination on April 10, 2024. CEMEX responded on May 9, 2024 asserting that the County made an error and did not correctly apply the applicable law and facts. In short, CEMEX has submitted an appeal to the Director of Community Permitting and Planning, that will require his response, prior to submitting an actual appeal to the Board of Boulder County Commissioners. CEMEX has been granted addition time to gather evidence, which includes an exceptionally large open records request that is taking the County a few months to prepare. We are awaiting both CEMEX's 'new' evidence, as well as the County’s response. We expect resolution of this piece to happen around Dec. 2024, and an appeal before the County Commissioners to happen around Mar. 2025.

    ——-

    The County has determined that the increased traffic at the plant created a hazard, which improperly expanded the use of the cement plant. Subsequently, a Notice of Termination was issued, which ceases the plant’s right to operate. CEMEX, however, has 30 days to provide evidence that the director’s determination was incorrect, reduce the enlargement of the cement plant use, or appeal the determination to the Boulder County Board of County Commissioners. CEMEX will be able to operate its cement plant under current operating conditions until a final determination is made. Given the recent rezoning of CEMEX’s parcel to agricultural zoning, Director Dale Case indicated that, under County Regulations, CEMEX would NOT be able to apply for a Special Use permit in order to potentially continue operations.

    This decision is a result of the complaint and investigation initiated by Good Neighbors of Lyons in January 2023, and supported by a petition signed by many County residents, as well as a letter signed by the mayors and many other elected officials in nearly every Boulder County municipality.

    While this is not exactly the end, this is the decision that we have been waiting on the edge of our seats for. We will share CEMEX’s response and expected next steps as soon as we know more.

  • Both the 1997-2000 Expansion Project (which was classified as a ‘Major Modification’ by the EPA) and the more recent 100%+ increase of truck traffic (confirmed in a recent traffic engineering study submitted by CEMEX to CDOT) clearly meet the County’s criteria to terminate CEMEX’s non-conforming status.

    We filed complaints to this effect in January 2023, and are expecting a determination from Boulder County Community Permitting and Planning by December 2023.

  • Should the County determine that termination is warranted, CEMEX would need to apply for a Special Use Permit in order to continue operations at their Lyons plant.

    There is a public process and vote associated with a Special Use, and there are 13 criteria in which a company would need to comply with in order to earn such a permit - we believe it would be very difficult for CEMEX to meet this criteria and win a vote.

  • Watch Our Webinar Explaining NonConforming Use, Jan 2023

    View Webinar Presentation Deck, Jan 2023

    Link to Case ZON-23-0003

    The 1997-2000 Lyons Plant Expansion

    CEMEX’s Documented Statements on Trucking Impact, Submitted Jan. 2023

    Good Neighbors Letter Signed by Local Mayors, Submitted Jan. 2023

  • On September 5, 2023 Boulder County announced that it is considering rezoning some ‘higher intensity’ areas around Lyons, which would include CEMEX’s plant (zoned General Industrial).

    Re-evaluating the zoning map is long overdue; just one example is that the plant itself has been in a floodway since the 2013 floods. Community Planning and Permitting Director, Dale Case, indicated that the potential rezoning was also in response to what the County heard from our community during the Dowe Flats Special Use hearings, which is that the Town of Lyons should have a voice in regard to some of the more intensive land uses in the Town’s 3-mile planning area. 

    The County ultimately suggested to down-zone all 20 properties highlighted for review to agricultural zoning.

    And later, on March 12th, the County Commissioners voted, in line with County staff’s recommendation, to rezone all of the ~20 properties impacted by this comprehensive rezoning effort from their more intense uses (ranging from Commercial to General Industrial) to Agricultural Zoning.

    This decision was consistent with what the Town of Lyons Board of Trustees ultimately decided would be best for the Town, as encouraging annexation into Lyons will assist the Town in establishing some much-needed growth to its tax base.

    Interestingly, Cemex did not provide written or verbal comment to the County County Commissioners or the Planning Commission regarding this rezoning. While a few other property owners also did not comment, we found this surprising as Cemex was the largest land owner impacted and this downzoning devalues their property by, conservatively, $15 million.

    Status: Complete. No further actions are expected to occur, unless property owners voluntarily elect to annex into the Town of Lyons.

Colorado Department of Public Health and Environment (CDPHE)

The Colorado Department of Public Health and Environment (CDPHE) and its Air Pollution Control Division (APCD) are responsible for enforcing air quality regulations in Colorado, including those mandated by the Clean Air Act (CAA), a federal law overseen by the Environmental Protection Agency (EPA). Boulder County Health works in coordination with these agencies to monitor local air quality. The General Emissions Monitoring and Maintenance (GEMM) program and Title V Operating Permits are key mechanisms to regulate industrial emissions, including "fugitive dust incidents," which refer to uncontrolled releases of dust.

  • *NEW Enforcement*: On May 2, 2024 CDPHE issued $1.39M fine against CEMEX for violations stemming from their 2022 annual inspection.

    Title V Renewal: CEMEX’s Title V (Air Quality) Permit is up for renewal and we are asking for modifications to better protect public health. We are expecting CDPHE to provide a revised draft permit and feedback on the hundreds of public comments received by late summer 2024.

    _____

    CEMEX's Title V (Air Quality) Operating Permit expired on March 1, 2022 and is up for renewal NOW. Our community submitted hundreds of written comments with requests for modifications to the permit, and showed up in force for a hearing before the AQCC on January 5, 2024.

    CDPHE recommended a renewal of CEMEX’s permit - supporting documents and a draft permit can be found HERE.

    Click here to learn more about what modifications we would like to see to CEMEX’s draft permit.

    Next Steps:

    • CDPHE has 30 days to approve, deny, or modify the permit (Feb. 6). CDPHE is backlogged and expect this to happen in late summer, 2024.

    • The EPA then has 45 days to respond.

    • We then have 60 days to appeal any decisions by CDPHE and the EPA regarding the permit.

  • In August 2023, CDPHE's Air Quality Control Commission required CEMEX to reduce its emission intensity rate by 7.77% under the GEMM program. A higher reduction of 10.68% was initially proposed, but a compromise was reached after CEMEX counter-offered a 0.97% reduction. Meeting these targets would necessitate substantial upgrades to this 54-year old coal-fired plant, posing a financial challenge for CEMEX.

    CEMEX’s first annual report will be due to CDPHE by May 1, 2026, and must demonstrate compliance with the facility’s annual emissions limitations.

    Supporting documents from CDPHE can be found HERE.

  • On May 2, 2024, CDPHE issued a $1.39M fine to CEMEX for violations stemming from its 2022 annual inspection.

    ———

    In July 2023, CDPHE and CEMEX settled on a $357,000 fine for air quality violations occurring between April 2020 and May 2021 (their ‘2021 Inspection’). An investigation related to incidents from the 2022 inspection is still in progress; we would anticipate more documented violations and an additional settlement.

    It is worth noting that this is one of our primary concerns with the Title V permit - there was no transparency, accountability, actions, or consequences for known air quality violations at the plant from April 2020-May 2021 until the settlement was reached and made public in July 2023. This lag in enforcement appears to be standard operating procedure, but does not lend itself to having any impact on improving air quality.

Colorado Department of Transportation (CDOT)

When our complaint was filed in December 2022, CDOT indicated that any permanent increase of truck traffic of 20% or more would require a new access permit. After a lengthy delay, CDOT finally received the required traffic engineering study from CEMEX in August 2023. The traffic engineering study confirmed truck traffic has increased more than 100% since 2022.

  • In September 2023, CEMEX was instructed to begin implementation of the new Highway 66 Access Control Plan immediately.

    However, as of May 2024 no construction or changes to drive patterns appear to have been made.

  • As part of CEMEX's recent permit update with the Colorado Department of Transportation (CDOT), a new Highway 66 Access Control Plan has been implemented to enhance road safety. This plan restricts CEMEX trucks from making left turns out of the plant onto Highway 66. This vital measure aims to mitigate traffic hazards and improve overall vehicular safety along this key thoroughfare.

  • Link to the Traffic Engineering Survey CEMEX Submitted to CDOT

    An added bonus of ensuring that CEMEX apply for a new CDOT Access Permit was that the data required for it (the Traffic Engineering Survey) would provide needed documentation in regard to the increased trucking element of the Boulder County Investigation. A needed step, because CEMEX stated in a letter to Boulder County on March 24, 2023 that “The Cement Plant has kept counts of inbound and outbound truck trips since 2019…. The numbers reflect the fluctuations in seasons and demand over the year. No single month since the closure of Dowe Flats in September 2022 has exceeded past months’ aggregate truck trips.” However, in reality, the study CEMEX itself commissioned showed an increase of ~230 truck trips PER DAY, which is a 100% increase compared to pre-September 2022 levels.

Colorado Department of Reclamation, Mining, and Safety (DRMS): Lyons Quarry Permit M1977208

DRMS mandates that reclamation bonds must be up-to-date, reflecting the current cost estimates for site remediation. This ensures that sufficient funds are available to restore the land to a safe and usable state if the operating company fails to do so.

  • On-going, but a recent decision confirmed an increased cost of one element of that reclamation (water clean up of the C-Pit, where cement kiln dust is buried) at $5.75M, bringing the current reclamation estimate to ~$21M + whatever cost the State assigns for reclamation of the asbestos-impacted structures (which Cemex asserts is 11,000 square feet, but we believe is more).

    Our goal is to have the bond set at no less than $30M to ensure tax payers are not liable for the environmental clean up of the site.

  • CEMEX’s $8.9 Million reclamation bond had not been materially updated in 20 years, which we raised concerns with DRMS about in January 2023.

    Cemex’s plant is nearing the end of its useful life and cement industry experts we have consulted with believe it is hanging on by a thread, financially speaking. Many companies in similar financial situations just walk away from plants like this and leave the clean up costs to taxpayers. In order to avoid this, Cemex must carry a bond to cover the current cost to reclaim/cleanup their property.

  • We filed complaints regarding the insufficient bond in January 2023. CEMEX issued a bond recalculation in March 2023 that merely added inflation to the 20-year old construction quotes (bringing their proposed bond to $11M), to which we immediately issued a detailed rebuttal as to its insufficiency. CEMEX provided a new calculation in August 2023, which had many errors, omissions, unclear methodologies, and even some unapproved changes to the reclamation plan itself.

    We provided another detailed rebuttal in September 2023. DRMS ordered CEMEX to fund the $11M figure, but negotiations were to continue.

    In March 2024, another update to the bond was made an increased cost of one element of that reclamation (water clean up of the C-Pit, where cement kiln dust is buried) at $5.75M, bringing the current reclamation estimate to ~$21M + whatever cost the State assigns for reclamation of the asbestos-impacted structures (which Cemex asserts is 11,000 square feet, but we believe is more). There are still several elements of our rebuttal yet to be addressed.

Webinar Explaining County Compliance

We held three separate webinars in January 2023 to provide updates to the community on our efforts since the closure of the Dowe Flats Mine last fall.

You can view the Presentation Deck HERE