However, details about how many credits those five companies purchased, and by how much they were allowed to offset emissions reductions through those purchases, remain a secret because state regulations prevent disclosure of those details.

The credit-trading program has been heavily criticized by environmentalists as a pay-to-pollute scheme that allows the state’s dirtiest industries to avoid making real changes to their greenhouse-gas emissions, which pollute the air and contribute to climate change.

The five companies that bid on credits were Cemex Construction Materials, a cement plant near Lyons; GCC Rio Grande, Inc., which makes cement in Pueblo and Penrose; Sterling Ethanol, a chemical manufacturer in Sterling; Suncor Energy’s oil refinery in Commerce City; and Yuma Ethanol, a chemical manufacturer in Yuma, according to the Colorado Department of Public Health and Environment’s auction summary. Sterling Ethanol and Yuma Ethanol are owned by Colorado Agri Products.

The sellers were Anheuser Busch’s Fort Collins brewery; Avago Technologies Wireless Manufacturing, which makes semiconductors and other electronic components in Fort Collins; and Western Sugar in Fort Morgan, according to the state’s auction summary.

Credits sold for about $25 each, and one credit equals one ton of carbon dioxide equivalents for one year. So if a company spent $100 at the auction, that company’s required emissions reduction would be four tons lower than what it otherwise would have been required to cut through improved technology or other measures.

In total, 2,760 credits were sold out of almost 106,280 credits offered.

Patrick Cummins, the health department’s director of environmental health and protection, said the state did not have any preconceived expectations going into the auction, but he was not surprised that so few credits were purchased.

“The companies offering and those bidding also didn’t know what to expect,” Cummins said.

Not every company that bid ended up buying credits, he said.

The Denver Post reached out to Suncor and Colorado AgriProducts to ask how the auction worked from their perspective, but representatives did not respond.

The details on which companies bought credits and how much they paid are kept secret to maintain a fair marketplace, Cummins said. If sellers knew how much a company was willing to pay, it could distort the market, he said.

Colorado’s Air Quality Control Commission, which establishes air pollution policies, created the greenhouse-gas credit-trading system while trying to come up with a plan to reduce by 20% the greenhouse-gas emissions from the state’s 18 largest manufacturers.

The plan allows companies that can lower their emissions beyond the mandated benchmark to sell credits to companies that struggle to meet the state’s emissions standards.

State regulators believed that by forcing the 18 largest industrial manufacturers to cut emissions, Colorado would move closer to its goal of eliminating all greenhouse-gas emissions by 2050. Those manufacturers include Suncor, Molson Coors, Western Sugar, Leprino Foods, Microchip Technology, JBS Foods and Cargill Meat Solutions, and they represent about 15% of all climate pollution emitted by industrial and manufacturing facilities in Colorado.

The majority of those 18 companies reduced their emissions below the specified levels they needed to meet in 2024 and did not need to buy credits, Cummins said.

The 18 companies will be evaluated and graded on their emissions reduction on a three-year cycle, and 2024 was the first year in the cycle, he said. There could be a greater demand for credits in the next two years as companies figure out how close they are to meeting the state’s mandated 2030 goal. But it is too early to predict whether some will rely on credits to make the goal, Cummins said.

Eight companies have told the state health department that they would achieve their 2030 reduction goals this year, Cummins said. Of the 18, only three exceeded the 2024 reduction requirements: Suncor, JBS Foods and Sterling Ethanol, according to the state’s greenhouse gas report.

Greenhouse gases include carbon dioxide, methane, nitrous oxide and fluorinated gases that trap heat in the atmosphere. Those gases linger and circle the Earth, causing global warming and climate change that brings on more severe weather such as large forest fires, rainstorms and intense summer heat. They also impact human health, causing respiratory and heart diseases and some cancers.

Colorado is planning to reduce its greenhouse gas emissions by 50% by 2030 and to zero by 2050, and the credit-trading program is just one of multiple programs in place to help the state reach that goal.

Last year, the state approved a credit-trading program for natural-gas operators. Other programs include a push to get more electric vehicles on the road, require state and local governments to use electric lawn equipment, and to shutter the state’s coal-fired power plants by the end of 2030.

When the credit-trading program was approved in 2023, multiple environmental groups said the system would create a loophole that would allow the state’s biggest polluters, such as the Suncor refinery in Commerce City, to buy their way out of making serious greenhouse gas reductions.

But business leaders and the governor’s office wanted the credit-trading system, fearing that burdensome regulation would force some companies to move out of state.

June’s greenhouse-gas credit auction occurred with little fanfare. Multiple environmental groups contacted by The Post did not know it had happened. And that, too, was criticized because state regulators have promised to be transparent with the people who live in neighborhoods closest to those large polluters and who are most impacted by the pollution.

Ean Tafoya, of GreenLatinos, said no one told him that credits had been sold and he did not completely understand what had happened.

“I’m left with more questions than I have answers,” he said. “I’m disappointed there wasn’t more enhanced community engagement on such an important issue.”

Ian Coghill, senior attorney for Earthjustice, said he was surprised by how few credits were sold and how little the credits cost, especially since the state has determined the social cost of greenhouse gas emissions equals about $89 per ton. That essentially puts a price tag on how pollution impacts the environment and human health.

“I assumed the credits would go for much more money,” Coghill said.

Story update: This article was changed on July 23 to report the correct number of greenhouse gas credits that were offered at auction.

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Here are some of the hundreds of responses, including comments from a variety of neighborhoods and from people who did and didn’t vote for Johnston in the 2023 election. Some responses have been lightly edited for clarity.

Ray Perry, Wellshire: “I did not vote for him but I would definitely support him in the future. I understand he is very controversial, but I completely believe his heart wants for what is best for Denver. I have never been more converted on a candidate before.”

Rachel Feres, Central Park: “Mayor Johnston’s leadership is all optics and no substance. He hasn’t solved homelessness — he’s just relocated it. His fiscal choices are reckless, favoring insiders while burdening taxpayers. Denver voters were right to reject his affordable housing tax. He’s lost the public’s trust.”

Beth McCann, Congress Park (former Denver district attorney): “I think he is doing well. … He was thrown a curve ball with the migrants and he might have spent too much money, but he couldn’t let them stay in the cold with no food and water. … I think that sometimes, he has great ideas but maybe doesn’t think through how to accomplish them.”

Denver’s mayor thinks big and moves fast — netting mixed results. Two years in, should he slow down?

Bill Winn, University Park: “Excellent job. He has vigorously addressed the homeless problem. He has stood up to federal overreach. He has a vision for Denver's future. Nice to have an honest and compassionate public servant.”

Giovanni Gomez, Five Points: “The biggest glaring miss is the absolute disgrace that is the Denver Police, DOTI and City Council’s failure to rein in the Mad Max traffic behaviors and protect residents who choose to walk and ride instead of driving.”

Heidi Hemmat, South Park Hill: “I think he’s doing a great job. I see far less homeless people in City Park and Civic Center Park. I have also noticed more police officers patrolling the neighborhoods. Overall, crime is down and I feel safer. I recently dined in LoDo, after years of avoiding the area, and it felt cleaner and safer. I think he’s on the right track and doing a great job, despite the challenges he faces.”

Rob Greer, City Park: “Eviction filings are still near record highs. Johnston has made negligible progress on housing affordability. He's also done far too little to combat car dependence and the pollution it causes.”

Mary Sue Kessler, Central Park: “He is very smart, extremely energetic and represented us well in the national congressional hearing on sanctuary cities.”

Aaron Knoll, LoDo/Ballpark: “I like his strategies on homelessness and his willingness to stand up for Denver on the national stage. I wish he did more or got the right people on city planning.”

Patrick Graham, Highland: “I think it is an incredibly mixed bag. On his signature issue -- homelessness -- it is undeniable that there are less encampments in and around downtown, but at what cost? The multiple attempts to drive the city further into debt are concerning, as are cuts to important services that all of us rely on.”

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Storms are expected to mainly impact the Palmer Divide and communities along and south of Interstate 70, with isolated severe hail and wind gusts possible, forecasters said in a hazardous weather outlook Saturday morning.

More severe thunderstorms are forecast for southern Colorado into the  I-25 corridor, NWS officials said.

“The strongest storms will be capable of 1.5 inch diameter hail, damaging wind gusts near 60 mph and locally heavy rainfall,” forecasters wrote. 

Whether the storms move farther east will depend on how the weather develops today.

“Stagnant” weather in the north metro could cause unhealthy air quality on Saturday for people who are sensitive to pollution, state officials said in an air quality alert for the Front Range urban corridor.

An ozone action day alert is in effect through the end of the day and people who are very active or have lung disease such as asthma should reduce prolonged or heavy exercise, according to the Colorado Department of Public Health and Environment.

This is a developing story and may be updated.

But environmentalists worry that is a big “if” as long as the Trump administration is in power, and now they are asking the Colorado Department of Public Health and Environment to include the Comanche Generating Station’s projected closure date of Jan. 1, 2031, in the Pueblo power plant’s latest Title V air permit.

They hope putting the date in a permit that needs Environmental Protection Agency approval will guarantee that Xcel, the largest utility company operating in Colorado, will shutter its last coal-fired power plant in the state by that deadline.

“I really want to emphasize the need to ensure that these retirement dates, which Xcel has committed to and everybody has agreed to, are established and set in stone via this Title V air permit,” said Jeremy Nichols, a senior advocate for the Center for Biological Diversity. “Right now, the federal government has launched an unprecedented assault on states like Colorado who are trying to do their part to confront the climate crisis and protect clean air and to enable a transition from coal to clean energy.”

Colorado’s utility companies have been planning for nearly two decades to shutter their coal-burning power plants and transition to cleaner alternatives, including natural gas, solar and wind power. Comanche is the largest coal-burning power plant in the state, and two of its three operating units still create electricity from coal.

Xcel is on track to shutter Comanche’s Unit 2 in September and remains committed to closing the plant’s Unit 3, which generates 750 megawatts of electricity, by January 2031, said Michelle Aguayo, a Xcel Colorado spokeswoman. Unit 1 is already closed.

“We continue to make significant progress towards our emission reduction goals approved by the state, which would require us to retire our coal units by (the end of) 2030,” Aguayo wrote in a statement. “We’re working with the administration and our states to continue delivering customers safe, clean, reliable energy while keeping our customers’ bills as low as possible.”

But President Donald Trump and EPA Administrator Lee Zeldin want the United States to continue burning coal, saying it is needed now more than ever to fuel a growing demand for electricity. That demand is being sparked, in part, by a growing reliance on artificial intelligence, which consumes massive amounts of power.

In April, Trump signed executive orders aimed at boosting the industry, calling it “America’s beautiful, clean coal,” and vowing to prevent states from curtailing its use. As part of that push, the president has ordered utilities in Michigan and Pennsylvania to keep their coal plants open even when some were on the verge of shutting down.

But Colorado officials pushed back, with Gov. Jared Polis calling the president’s orders “federal overreach.” By eliminating coal-fired power plants, Colorado will inch closer to meeting its goals for cutting greenhouse gas emissions and addressing climate change.

Now, though, Polis’ regulators are being asked to put that commitment in writing.

“We are exploring if we would have legal authority to include an enforceable retirement date for Comanche’s Unit 3 coal plant in the draft Title V operating permit — and what exactly that would mean,” said Kate Malloy, an Air Pollution Control Division spokeswoman.

Coal is a dirty substance, emitting more carbon dioxide than other energy sources and accelerating climate change. Coal also contains multiple other contaminants such as mercury, sulfur dioxide, fine particulate matter and nitrogen dioxide that are released into the air and are a threat to human health.

It also leaves a toxic byproduct called coal ash, which contains arsenic, lithium, selenium, cobalt and other metals, that must be dumped into landfills in the state. Millions of tons of coal ash are buried in Colorado, and at least three sites have been documented as leaking lithium and selenium into groundwater.

Even though Xcel plans to shutter Comanche’s Unit 3 within five years, it still needed to renew its Title V air permit, the document that details how much pollution the company is allowed to spew into the air.

Under the proposed permit, the amount of pollution coming from Comanche would be reduced by thousands of tons of particulate matter, sulfur dioxide, nitrogen oxide, carbon monoxide, volatile organic compounds and hazardous air pollutants, said Carrisa Money, the state health department’s Title V operating permits unit manager.

The permits are supposed to be renewed every five years. Xcel’s was last renewed in 2018.

Xcel submitted its renewal application in 2022, and now the Colorado health department is on the verge of approving it.

The state’s Air Quality Control Commission, which sets state air pollution regulations, on Tuesday held a public hearing on the permit application at which five people asked the state to do its part to slow climate change. Another 54 people submitted letters, most of which asked for the closure date to be included in the permit.

“We want to be responsive to the feedback we have received and do what’s best for Colorado, so we are working to evaluate this issue,” Malloy said in an emailed statement. “Once we have an answer, we will respond to public comments as appropriate.”

Utility companies like Xcel plan for years to shutter power plants as they replace coal with cleaner power generation. And they set goals with approvals from the Colorado Public Utilities Commission, which is responsible for making sure there is enough power surging through the grid to keep people’s lights on at an affordable price.

Malloy noted that the Comanche Unit 3 retirement date is enforceable through the company’s clean energy plans, which are required by state law and were submitted with Xcel’s electric resource plan to the PUC. The Air Pollution Control Division supports clean energy plans by verifying data and sharing them for public review and input, she said.

“Even if a federally enforceable permit condition were not on the table, the state does still have oversight and enforcement authority for coal plant retirement dates,” Malloy said.

But that hasn’t stopped Trump from making his demands. So Nichols believes it is necessary for the state to put the closure date in the Title V permit.

“We urge Colorado to create a bulwark, a defense, so to speak, against the federal government’s attacks on our climate progress and our progress in transitioning away from coal,” Nichols said during Tuesday’s public hearing on the permit. “I think that emphasizes the need to find perhaps more creative ways to ensure that the Comanche coal-fired power plant retirement dates are fully set in stone through this Title V permit.”

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Two employees in the EPA’s Region 8 headquarters in Denver and one who works at the EPA’s National Enforcement Investigations Center in Lakewood are under investigation for signing the letter, said Kate Tribbett, vice president of the American Federation of Government Employees Local 3607, which represents Region 8 employees.

The “Declaration of Dissent” letter, which was sent to Zeldin on Monday, was published on the Stand Up for Science website, and shows at least 13 current and retired Region 8 employees as signatories. The letter accuses Zeldin of undermining the agency’s mission to protect the environment and human health.

“It’s an interesting way to celebrate Independence Day to put people on administrative leave for using their First Amendment right to speak freely,” said Britta Copt, president of Local 3607.

It appears the signatories who serve as union officers or stewards have not been placed on leave, Copt said. Those who have taken early retirement or a buyout have not been affected by the administrative leave.

The employees on leave will be investigated for using government time and computers to sign the letter, Copt said. The union will defend those employees’ rights to free speech and is demanding the EPA recall the workers and end the investigation, she said.

EPA press secretary Brigit Hirsch wrote in a statement to The Denver Post, that the agency “has a zero-tolerance policy for career bureaucrats unlawfully undermining, sabotaging and undercutting the administration’s agenda as voted for by the great people of this country last November.”

Region 8 administrator Cyrus Western, who was appointed by President Donald Trump, personally spoke to the two from the Region 8 office who were placed on leave, Tribbett said. Those who were in the office were escorted out of the building by security, she said.

“That is very unusual and only done in the past when the employee was thought to be a threat,” Tribbett said.

The notice sent to employees said they would be on paid administrative leave until July 17, pending an investigation, according to a copy obtained by The Post. It did not explain why the employees were under investigation.

“During the time you are on administrative leave, you will not experience any loss in benefits or pay. You are required to provide a current email address and phone number so that we can contact you as part of our investigation,” the letter stated.

“Please verify your contact information with the individuals included on this email immediately. You will be expected to be available at the phone number provided above (and/or by any additional or alternative contact information you provide) during your regular duty hours in accordance with your currently approved work schedule should the agency need to contact you.”

The “Declaration of Dissent” letter, which was signed by 230 people and copied to Congress, accuses Zeldin of undermining the EPA’s mission of protecting human health and the environment.

“Since the agency’s founding in 1970, EPA has accomplished this mission by leveraging science, funding and expert staff in service to the American people,” the letter states. “Today, we stand together in dissent against the current administration’s focus on harmful deregulation, mischaracterization of previous EPA actions, and disregard for scientific expertise.

“Since January 2025, federal workers across the country have been denigrated and dismissed based on false claims of waste, fraud and abuse. Meanwhile, Americans have witnessed the unraveling of public health and environmental protections in the pursuit of political advantage.”

It lays out five areas of concern: undermining public trust, ignoring science to benefit polluters, environmental justice, dismantling the EPA’s Office of Research and Development, and creating a culture of fear.

Under Zeldin’s leadership, the EPA has reduced employment across the country, cut funding for environmental justice, proposed repealing rules that limit emissions from coal-fired power plants, frozen grants for clean energy projects and tried to undo a ban on asbestos.

Cindy Beeler, a former energy adviser in the Region 8 office, said she signed the letter because Zeldin and Trump are eroding the EPA’s important role in the United States. She said similar moves in other agencies, such as the National Institutes of Health, also worry her.

“The attack on science has been happening for years and years and years now,” Beeler said.

The EPA’s Office of Research and Development was world-renowned for its work on environmental problems. During her career, Beeler said it was the EPA’s research on methane that led to national policy that directed oil and gas companies to reduce emissions at their drilling sites.

“Without that emissions data, you can’t make a rule,” she said. “Scientific research has been shut down. You can’t just pick it back up in a month or a year and say, ‘Let’s start those Petri dishes again.'”

The Associated Press contributed to this report.

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Xcel plans to scoop most of the coal ash from a landfill at the site and turn it into an ingredient in concrete to be sold in metro Denver. The project awaits approval from the Colorado Department of Public Health and Environment.

The utility company expects to spend $24 million over the next 10 to 12 years to remove ash and treat contaminated groundwater, said Michelle Aguayo, an Xcel spokeswoman.

Officials at Boulder County Public Health are on board with the coal-ash cleanup, saying that recycling hazardous waste into a useful product is a proven solution. It would rid the site of a toxic substance and prevent anyone from trucking it to another community.

“That’s one reason we like this project — we’re not just putting this project on someone else. Another reason we like it is it will be a net greenhouse gas reduction,” said Bill Hayes, the county health department’s air quality program director. “We aren’t trucking it nationally. We are creating something that will be used locally and won’t have to be trucked in from thousands of miles.”

“Boulder County Public Health supports the project,” he said. “The beneficial use project will have global impacts. But there will be some risk with it.”

Xcel will be the first utility company in Colorado to initiate such a large-scale coal-ash cleanup after lithium and selenium leaked into groundwater and seeped toward wells used for drinking water on nearby properties.

But there are millions of tons of coal ash in other landfills and ponds around Colorado, and almost all of those sites are leaching pollutants into groundwater.

Over the years, public reporting of coal-ash contamination has been inconsistent because there was no regulation of the waste before 2015. Even after that, utility companies were only required to report monitoring results from landfills that were still in use — and those documents can be hard to find and difficult to understand.

Then, last year, the Biden administration expanded those reporting requirements to all waste disposal sites, although nothing has yet resulted from that rule change.

In 2022, two environmental organizations compiled a list of coal-ash waste sites across the United States, using Environmental Protection Agency reports, and their research identified 12 known coal ash locations in Colorado.

Earthjustice and the Environmental Integrity Project estimated that over the decades 14 Colorado power plants created more than 1.7 million tons of ash per year that went into landfills and retention ponds, according to their 212-page report.

The report placed three of Colorado’s coal-ash waste sites among the 50 most contaminated sites in the United States.

While Xcel has a plan to remove coal ash at the old Valmont station, environmentalists say it is unlikely that most utility companies will clean their sites unless forced by federal or state regulators, or if sued by impacted communities. Utility companies have a track record of doing the minimum amount required under the EPA’s Coal Combustion Residuals rules, said Abel Russ, senior counsel with the Environmental Integrity Project.

“They find ways to formally comply with the rule but not do much with cleanup because it’s expensive and they don’t want to spend the money,” Russ said.

Xcel’s cleanup project at Valmont comes as the Trump administration shows little appetite for enforcing existing coal-ash disposal rules, as the president and EPA Administrator Lee Zeldin push their “Powering the Great American Comeback” agenda, which prioritizes coal as a leading source of energy in the country.

On Thursday, a Republican-controlled House environmental subcommittee held a hearing to review coal-ash regulations and to discuss whether or not “government red tape and bureaucracy can stifle innovation surrounding the use of coal ash,” according to an announcement of the hearing.

In Colorado, utility companies are phasing out coal-burning power plants as the state strives to reduce its greenhouse-gas emissions and pivot toward renewable energy such as wind and solar. Those companies will continue to produce coal ash until that happens. Meanwhile, the retention ponds and landfills that have held the ash for decades are not going away.

For example, Tri-State Generation and Transmission Association’s ash disposal facility near its Nucla Station in Montrose County received waste from 1987 until 2019, when the coal plant was retired. The company reported last year that 4.8 million tons of coal ash are in a landfill, and that the electric cooperative continues maintenance at the waste site.

Last year, Tri-State said it had taken steps to prevent erosion, including adding riprap along the perimeter and building a 1.5-foot-tall berm, according to the company’s 2024 inspection report.

The Valmont Power Station on North 63rd Street in Boulder operated as a coal-fired electricity generation station for almost a century, until it was converted to a natural-gas-powered station in September 2017. During that time, Xcel dumped its coal ash — also known as coal combustion residuals — into three ponds and a landfill.

In 2020, Xcel’s groundwater monitoring detected lithium and selenium leaching from a 60-acre landfill that was in operation from 1993 until 2017. That led the company to come up with a plan to remove the ash from the site and stop the leaks.

But it’s been a long process.

Xcel submitted its engineering and design plan earlier this year to explain how the cleanup will work. That plan is still under review by the state health department’s Hazardous Materials and Waste Management Division and will be subject to public comment once preliminary approval is given.

The company also must apply for a permit to emit pollutants into the air during the cement-making project, and that must also be approved by the state.

Work cannot start until those approvals have been given. Still, Xcel says it will begin in 2026.

A national problem

Nationally, 5 billion tons of coal ash are estimated to have been created by coal-powered electricity plants since the late 1800s, said Lisa Evans, senior counsel with Earthjustice, a nonprofit environmental law group.

Coal ash is the second-largest industrial waste stream in the country, accounting for 70 million tons pouring into landfills and retention ponds every year, Earthjustice research found.

“If you ask if there’s a big problem with coal ash in the U.S., the answer is yes because coal ash was mismanaged for decades,” Evans said.

Hazardous chemicals found in coal ash include arsenic, boron, cobalt, chromium, lead, lithium, radium and selenium. Those chemicals are known to cause an increased risk of various cancers, heart and thyroid disease, respiratory illnesses and neurological problems.

Lithium is a naturally occurring metal and has various commercial uses, including as a material used in batteries. The EPA has placed lithium on a list of priority contaminants in drinking water, but has not established regulations on how much is an acceptable minimum level. Lithium has been known to cause renal and neurological problems in people.

Selenium is also a naturally occurring metal and has useful purposes, including as an essential nutrient at low levels. The EPA has established a maximum level for that metal, which can damage the liver, kidneys, nervous system and circulatory system, and cause hair loss.

Coal-ash disposal in the United States was unregulated until after the December 2008 Kingston TVA coal ash spill in eastern Tennessee.

In that disaster, a dike used to contain coal ash broke near the Tennessee Valley Authority’s Kingston Fossil Plant in Roane County, dumping 5.4 million cubic yards of toxic coal ash into nearby water, including the Emory and Clinch rivers, and contaminating more than 300 acres of land. It took more than six years to clean the mess from rivers and streams, and private property. Hundreds of workers were sickened — and dozens died — from exposure to arsenic, lead, mercury and radium that was in the coal ash.

“That was just so dramatic that it focused everyone’s attention on it. It reminded everyone that it’s a huge waste stream,” Russ said.

When Americans first started burning coal to provide electricity, no one thought about the ash byproduct left over after the coal burned. The ash was dumped in unlined lagoons and landfills without much thought.

“It’s the sheer volume of it and the concentration of heavy metals in it,” Russ said. “They didn’t wrap their heads around it until it was too late.”

The EPA established the first rules for coal-ash management in 2015 in the wake of the Kingston disaster. The rules addressed the risks associated with coal-ash disposal, including leaks into groundwater, dust blowing into the air and failures of barriers around landfills.

The federal government also began requiring record-keeping and reporting at active coal-ash landfills across the country, and the regulations allowed for the beneficial use of coal ash, which is what Xcel is planning for the Valmont Power Station in Boulder.

Those 2015 rules only applied to active landfills and excluded some of the oldest coal-ash ponds and landfills in the country. In 2024, the EPA, under President Joe Biden, tightened rules governing those older ponds and landfills that required monitoring for pollutants and cleanup.

However, the Trump administration has already signaled that it will not prioritize coal-ash enforcement, Evans said.

In March, Zeldin announced a plan to shift coal-ash regulation to the states with EPA support, and pledged to change the rules on compliance deadlines by the end of this year.

That means there will be uneven enforcement across the country, with coal-friendly states such as Wyoming and North Dakota becoming lax while other states, including Colorado, tackle the challenge, Evans said.

“Coal ash is like running on a treadmill. We gain ground and lose ground,” Evans said. “We made progress with Obama, and Trump tried to rescind it, but ended up just delaying. Then we got a new rule with President Biden to fill the gaps. And now the Trump administration wants to undo it.”

A Colorado problem

There are 12 known locations in Colorado where coal ash has been dumped, and those sites include 38 coal-ash ponds and landfills, according to a database maintained by Earthjustice. There could be other unknown sites where coal ash was stored long before any regulations existed, the environmental group says.

Those 12 sites are on the grounds of former or active coal-burning power plants, or nearby landfills, and are the responsibility of the utility companies that own them. It’s unclear exactly how much coal ash is buried in the ground in Colorado because of incomplete reporting.

Xcel is responsible for seven of the coal-ash waste sites in the state: the former Arapahoe Generation Station in Denver; the former Cameo Generation Station in Mesa County; the Cherokee Generation Station in Denver; the Comanche Generation Station in Pueblo; the Hayden Generation Station in Routt County; the Pawnee Generation Station in Morgan County; and Valmont.

The other sites in Colorado include: Colorado Springs Utilities’ Clear Spring Ranch Landfill, which holds waste from the Ray Nixon Power Plant and the former Martin Drake Power Plant; Tri-State Generation and Transmission Association’s Nucla Ash Disposal Facility, which holds waste from its former Nucla Station in Montrose County and its Craig Station in Moffat County; and the Platte River Power Authority’s Rawhide Energy Station in Larimer County.

Earthjustice also reported there is a coal-ash waste site at the former Martin Drake Power Plant in El Paso County, but there are no available reporting documents online and efforts to reach Colorado Springs Utilities were unsuccessful.

It is also unknown whether there is coal-ash waste associated with the former W.N. Clark Power Plant in Fremont County, which was decommissioned in 2012.

Earthjustice lists three Colorado coal-ash sites among the 50 most contaminated in the country because they have multiple pollutants exceeding EPA standards: Valmont is ranked 31st; Tri-State’s retired Nucla station is 39th; and Xcel’s Hayden Station is 44th.

While it is unclear exactly how much coal ash is buried in landfills and sitting in retention ponds across the state, a Denver Post review of available 2024 coal combustion residual inspection reports found more than 30 million tons at the various sites. No reports are available for landfills that were closed before 2015.

Xcel’s seven sites contain more than 19 million tons of coal ash, according to inspection reports the company posted online. However, not every Xcel disposal site has an updated report on the company’s coal-ash management website, in part because of the change in reporting rules for coal-ash sites. The Post found online reports missing for Arapahoe, Cameo, Cherokee and Pawnee’s north landfill sites.

Xcel declined to make its coal-ash managers available for interviews with The Post. Instead, Aguayo, the company’s Colorado spokeswoman, sent an emailed statement and referred the newspaper to the company’s website for any information on coal-ash management.

“Protecting our customers and the environment is a priority, and we have a strong record of environmental leadership,” Aguayo said in the statement. “We’re committed to responsibly managing impacts from our operations, including from prior coal plants, like Valmont.”

In the past three years, Xcel has been cited twice by the EPA for failures to comply with coal-ash regulations.

Xcel’s Cherokee Generating Station transitioned to a natural-gas-fired power plant in 2017 and closed five dumpsites, including a retention pond, on the property. But closing a coal-ash disposal location does not mean the coal ash is removed. Rather, no more waste is dumped there.

Xcel was fined $134,500 in September after lithium was discovered leaking from its Cherokee plant, identifiable by its red-and-white smokestack visible from north Denver. The EPA cited the company for failing to adequately prepare groundwater monitoring reports, failing to meet groundwater monitoring performance standards, failing to accurately represent readings in groundwater quality, and failing to use the most effective statistical methods to analyze groundwater data, according to the agency’s consent agreement.

Xcel agreed to correct its missteps, according to the consent agreement between the company and the EPA.

The utility is still assessing how to treat the lithium plume, said Lauren Whitney, a state health department spokeswoman. Xcel is evaluating two solutions and will hold a public meeting before selecting a method and starting work.

But that’s not the largest fine Xcel has paid for coal-ash violations.

In 2022, the EPA penalized the company for failing to comply with regulations on the disposal of coal ash and not properly monitoring groundwater at its Comanche station in Pueblo. The company paid $1 million to settle with the federal government.

That site is releasing cobalt into the groundwater.

Xcel has identified the plume, tested the groundwater and is putting together a remediation strategy, Whitney said.

Between August 2024 and February, the remediation strategy included injecting a treatment reagent into six injection wells using an EPA-approved method, Whitney said. Wells near the plume did not have cobalt levels that exceeded the drinking water standards.

Meanwhile, Xcel continues to dump coal ash into a landfill in Pueblo until the coal plant is decommissioned, no later than Dec. 31, 2030. As of 2024, about 4.9 million tons of coal ash are in the ground at Comanche, according to the most recent inspection report.

Cleaning up Valmont

Valmont Station will be the first site in Colorado where Xcel plans to convert coal ash into Portland cement, an ingredient used to make concrete. And it is the only site with such a massive cleanup in the company’s plans, Aguayo said.

The company has contracted with Charah Solutions, a Kentucky-based company that specializes in coal-ash management and cleanup. Charah has hired Geocycle, an industrial waste management company, to help with the project, Aguayo said in the utility’s statement.

Charah is expected to process about 2 million tons of ash over 10 years to remove the hazardous waste.

Charah and Geocycle use a proprietary system to recycle the ash into cement. It involves a mobile kiln that would be set up on the Valmont property, and the companies would use a baghouse — an industrial dust collector — to prevent harmful air emissions, Aguayo said.

Charah will only excavate the amount of ash that its workers intend to process in one day to avoid leaving excess ash on the ground that could blow into the community at night when the work stops, she said. The equipment is enclosed to manage dust, and the noise it makes is similar to Valmont’s normal operations.

The cement created onsite will be sold and used in the Denver market, Aguayo said.

“This project provides large-scale environmental benefits by eliminating the need to mine new raw materials for Portland cement and by eliminating the need for cross-regional transport of Portland cement and/or concrete to Denver’s local market,” her statement said.

Operations will run during daylight hours, seven days a week. Work will stop when wind gusts exceed 55 mph or sustained winds exceed 40 mph, according to the company’s engineering and design plan.

Once the ash is removed, the contractor will grade the area and put down clean soil and grass seed. Any ash that is not suitable for recycling will be placed in a specific area of the landfill, and then the landfill will be closed.

Hayes, the air quality manager at Boulder County Public Health, said he is most concerned about how much dust will flow into the air once the project starts. The engineering and design plan calls for dust control systems but lacks details.

“That’s what I’m really waiting to see are the controls we want to see in that dust control plan,” Hayes said. “The dust concerns from start to finish are when they are excavating the landfill sites.”

Hayes hopes more of those details will be included in the company’s air-pollution permit. He wants the state health department to require continuous air-quality monitoring at the site, but so far, the state has not agreed to consider it once the air permit is filed.

“CDPHE says they’ve never required it in an air permit,” Hayes said. “I said, ‘Yeah, but we’ve never issued an air permit for a coal-ash landfill project.’ This is a unique and novel project, and we just don’t need to go with what we’ve done in the past.”

Hayes said he’s not optimistic that a monitoring requirement will be included in the air permit, so he is searching for outside funding to pay for it.

“In our current climate, getting funding for air monitoring is proving to be a little challenging,” he said. “Federal grants that used to be available for that are dwindling and going away.”

But the air quality problem at a coal-ash landfill only occurs once a company starts excavating the material.

The more critical problem at most coal-ash waste sites is the groundwater contamination.

“It’s a huge problem. We’ve been burning coal since the early 1900s,” said Evans, with Earthjustice. “The ash was not regulated until 2015, so billions of tons of coal ash have been dumped in pits and ponds and used as fill across the United States. Almost every state had a coal-burning power plant.”

For years, companies were allowed to dump the ash without lining the landfills. More than 90% of coal-ash waste sites have contaminated groundwater above federal safety standards, she said.

“It’s not an exaggeration to say that whenever you dump coal ash, you’re going to get water contamination,” Evans said.

At the Valmont Station, Xcel has monitored groundwater with a network of wells that the utility drilled in the area, said Carl Job, a water quality specialist with Boulder County Public Health. Those wells detected elevated levels of lithium and selenium in a plume moving north and east of the property, and the plume was moving toward nearby drinking water wells.

Xcel filed an ash landfill remedy selection report, which proposes a cleanup method, in May with the state health department. The report said two plumes were creeping out of the landfill. The first plume contains elevated concentrations of lithium and selenium, while the second plume exceeds lithium levels mandated by the EPA.

“These plumes are not adversely impacting drinking water in the area, and the groundwater will continue to be monitored to ensure ongoing protection of human health in the area until remedy completion,” the report stated. “There are also no public drinking water supplies in the vicinity of the impacted groundwater.”

The contaminated plumes are not a threat to most Boulder residents, who get their water from the city system, Job said. The real concern surrounds the few wells nearby where people get their drinking water, which are not as regulated as public water systems.

Only one well has shown higher levels of lithium contamination, and Xcel is providing an alternate source of water, said Erin Dodge, Boulder County Public Health’s water quality program coordinator.

The plumes are not impacting Boulder Creek or South Boulder Creek, she said.

Groundwater remediation is proceeding under a compliance order from the state, Whitney said. Xcel has submitted a proposal for treating the groundwater, and it is under review by the state and Boulder County. Once it is approved, Xcel will submit a design plan for the state health department to review.

Xcel is proposing to use reverse osmosis, which is a proven method for cleaning water. That system will extract groundwater through wells and collection trenches and truck it off-site for treatment, the report said.

The remedy selection report estimated it would take 15 to 35 years to treat the groundwater.

Meanwhile, there is no other long-term plan for removing the millions of tons of coal ash buried in Colorado.

Some utilities, such as the Platte River Authority, sell some ash for beneficial reuse. Platte River sells ash to architectural block manufacturers and to liquid-waste disposal facilities, according to its company website.

Officials at the Colorado Department of Public Health and Environment say they are committed to making sure coal ash does not contaminate groundwater.

The state regularly monitors coal-ash waste sites, said Tracie White, director of the health agency’s hazardous waste division. And Valmont is of particular interest because of the size of its ash reuse project.

“We are committed to making sure coal ash landfills in Colorado are protective of human health and the environment,” White said. “At Valmont Station, our team is closely reviewing the proposed cleanup remedy to ensure it meets all state regulations and prevents further impacts to groundwater. We regularly monitor these sites to track, trace, and treat potential contamination, and we work in partnership with local communities throughout the process.”

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The violations pertain to well control, general safety requirements, oil and gas facilities operations, air, water and soil pollution, and natural gas venting, according to a presentation to the commission about the April blowout, which covered a school and homes near Galeton with pollutants and will take five years to clean up.

The ECMC served Noble Energy with a notice of the alleged violations, the first step in launching a formal investigation into missteps that caused thousands of barrels of crude oil, natural gas and fracking water to spew from the Bishop well pad. The company has 28 days to respond to the allegations.

Jeff Deranleau, the ECMC’s deputy director of operations, said the commission’s investigation could lead to fines and other enforcement actions for the company. The investigation could take months, and the penalties will be negotiated between the state and Chevron. The seven-member ECMC board must give final approval of any penalties.

The decision to pursue an investigation into rule violations follows Chevron’s submission of a root-cause analysis on June 10 that pinned blame on a subcontractor and also on its employees for improperly installing equipment at the wellhead to regulate the flow of oil, gas and water from the ground.

The company’s two-part explanation said the blowout happened during a period after fracking had been finished and before extraction began.

But the ECMC’s notice of alleged violations did not name the subcontractor nor any other individuals working for Noble Energy or Chevron.

“I want to note that, importantly, regardless of who or what causes an accident, spill, leak or other incident on an oil and gas location, the ECMC holds the operator of record accountable for the operations conducted on their location as the control of the location is solely in their hands,” Deranleau said.

Noble Energy, which is a wholly owned subsidiary of Chevron, holds the drilling permit.

Patty Errico, a Chevron spokeswoman based in Colorado, said in an email that the company was reviewing the violation notice. The cleanup and remediation continue, and the company will cooperate with federal and state agencies, she said.

“We understand that rebuilding trust takes time and sustained effort. We remain committed to open, ongoing dialogue and to supporting the residents of Galeton as we move forward — together,” Errico’s statement said.

The state’s notice alleges that Chevron failed to prevent oil, gas and water from flowing uncontrolled from the well and failed to follow general safety requirements, leading to at least one worker’s injury when the blowout happened, according to the document.

As for the pollution violations, the blowout spread contaminants to a school, homes, farmland, surface waters, wildlife habitat and livestock, the notice of alleged violations stated. The company failed to prevent the pollution and its adverse impacts.

The blowout also violated the water quality standards established for oil and gas operations after Chevron built an unlined pit to retain runoff from the blowout.

Finally, the notice alleges that Chevron vented natural gas from the well, which is a violation of state rules.

The blowout was one of the largest spills in Colorado in recent memory, Deranleau told the commission.

“Well-control incidents are rare,” Deranleau said. “The specific cause of this incident, as reported by Chevron, is related directly to proprietary equipment and improper assembly of the equipment, meaning it’s not even the same root cause of other well control incidents that have happened in the past in Colorado or elsewhere.”

After the blowout, the ECMC sent a notice to 42 other oil and gas operators in Colorado, advising them of the incident and asking each company to report to the state how it handles equipment installation between fracking and extraction.

Their responses and the ongoing investigation into the Bishop well blowout could lead to policy changes, said Mike Leonard, the ECMC’s quality assurance/quality control manager.

The massive blowout occurred at 5:50 p.m. April 6 at the Bishop well south of Weld County Road 74, near Galeton, about 14 miles east of Greeley. It lasted five days, leading to the closure of Galeton Elementary School and the evacuation of 14 families. One worker suffered a broken leg when a piece of equipment fell on him during the incident, Deranleau said.

The blowout spewed 20,000 barrels of water and 5,000 barrels of hydrocarbons into the air, and those liquids covered the school, homes and other structures within a 1.5-mile radius of the well — an area that covers seven square miles, or 4,500 acres.

Toxic chemicals, including benzene, hung in the air, flowed into ponds and streams and seeped into the groundwater.

The state has divided that area into 300 parcels that each have a specific remediation plan, and the ECMC expects the cleanup to last through 2030.

So far, the ECMC has received 730 surface water samples, 2,203 soil samples and 475 air samples, said Kyle Waggoner, the commission’s east environmental supervisor. The agency is also conducting tests on the surfaces of the school, homes and other structures that have been cleaned to make sure all hazardous pollutants have been removed.

“How do we make this a successful remediation site? In other words, how do you eat an elephant?” Waggoner said.

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While all eyes are focused on chaos in the Middle East, the federal tax credit ($7,500) for electric vehicles is threatened and the Colorado tax credit (now $1,500 – $8,000) will be cut in half. With a price change like that, last year’s record sales will, naturally, plummet. That’s a problem.

Last summer in scenic Denver, there were 40 days when ozone levels exceeded federal standards. Often, we can’t even see the mountains. It’s also getting too hot, all the way from Denver to the high peaks. Saint Mary’s Glacier, along with a lot of other alpine snow, is melting. As a result, the high mountain forest ecosystems that depend on it are threatened.

Instead of continuing to fund tax credits, we are looking to pipelines as cheap and easy options during these tumultuous times. But crazy times actually demand wisdom and perspective. Oil prices are going up and the chaos does not seem to be subsiding. It’s time to curb our carbon production and oil dependence by getting more electric vehicles on the road. We live in Colorado with ample sources of local energy, including the nearly 40% of our electricity that already comes from wind and sun. We have sustainable and secure options.

Tell your elected officials in the state legislature you want to keep tax credits for electric vehicles at their current levels.

Shakti Io Anderson, Lakewood

‘What are the Democrats thinking?’

President Joe Biden pulled out of Afghanistan in utter chaos. Thirteen service members were killed. The loss of military equipment was extensive. It was met with a yawn by the Democrats. For years, Iran has taunted us with “Death to Americans” and full steam ahead for nuclear weapons.

In a well-coordinated plan, President Donald Trump destroyed nuclear plants in Iran and supported our only democratic ally in the Middle East. Under Rep. Alexandria Ocasio-Cortez’s direction, the Democrats are now calling for President Trump’s impeachment. What are the Democrats thinking?

J.D. Moyers, Centennial

Taking stock in America’s greatness

The Trump administration’s meat cleaver attacks on free trade, immigration, inclusion, education, and research are killing the goose that lays golden eggs. Donald Trump will not “Make American Great Again.” He is attacking what made this a great nation.

I will be 80 in September, and I’ve seen what made America great. We are a great country because: 1) we are diverse, comprised of people coming all parts of the world seeking a better life; 2) our aspiration to assure “liberty and justice for all,” while imperfectly realized, has distinguished our country from places where religious intolerance and political and economic oppression are rampant; 3) we have embraced free enterprise, seeking to regulate business only as needed to avoid fraud, monopoly, exploitation, and the destruction of our environment; 4) we have invested in public education to provide opportunity and strengthen our workforce and our democracy;  and 5) we have massively invested in research to learn how to improve the quality of human life.

Of course, we need to manage immigration, but these are the reasons students from all over the world want to study in our colleges and universities. Republicans and Democrats who understand what made America great need to join hands and protect what we have inherited.

Paul Lingenfelter, Denver

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The ozone action day alert applies to the Front Range urban corridor, from Douglas County south of Denver to Larimer and Weld counties north of the city, according to the Colorado Department of Public Health and Environment.

Hot, sunny and stagnant weather will create levels of ozone that are “unhealthy for sensitive groups,” state health officials said in the alert, which will remain in effect until the end of the day.

The highest ozone concentrations are expected south and west of Denver and along the Interstate 25 corridor, according to the alert.

Until the alert expires, active children and adults, people with lung disease and asthma and others sensitive to ozone in the affected areas should avoid rigorous outdoor activity during the heat of the day.

State officials said short-term exposure to unhealthy ozone levels can cause coughing; eye, nose and throat irritation; chest pain; difficulty breathing; and asthma attacks. Long-term exposure has been linked to both lung and heart disease.

Ozone levels are expected to improve to the good to moderate range by Friday.

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Colorado, which had adopted California’s rules two years ago, quickly joined California and nine other states in a lawsuit to challenge the move.

Trump signed a resolution that was approved by Congress last month that aims to quash the country’s most aggressive attempt to phase out gas-powered cars, which are a leading source of greenhouse gas emissions in the country. Trump also signed measures to overturn state policies that curb tailpipe emissions in certain vehicles and smog-forming nitrogen oxide pollution from trucks.

“The Trump administration’s attack on clean air is breathtaking,” Colorado Attorney General Phil Weiser said in a news release announcing the lawsuit. “We’re in court to defend Colorado’s cost-effective clean car program, which was implemented to improve air quality, reduce harmful ozone pollution, and increase choices that Coloradans have when purchasing an electric vehicle.”

The Colorado Air Quality Control Commission partially adopted California’s rules in 2023, which was allowed under the Environmental Protection Agency’s regulations.

In Colorado, the clean cars standards would have required auto manufacturers to make and sell more electric vehicles starting with model year 2027 and increasing each year until 2032, when 82% of all vehicles sold in the state were to be electric. The standard also required new conventional cars and passenger trucks to lower tailpipe emissions.

Colorado’s adoption of California’s Advanced Clean Truck standards also required medium- and heavy-duty truck manufacturers to sell an increasing percentage of zero-emission vehicles starting in 2027.

Colorado also adopted California’s Heavy-Duty Low Nitrogen Oxides rule requiring heavy-duty truck manufacturers to make cleaner heavy-duty trucks for sale or lease in this state starting in 2027.

Colorado’s clean cars rule was not as stringent as California’s because it did not block all sales of gas-powered vehicles.

Still, the state is pushing zero-emission vehicles as it strives to eliminate almost all greenhouse gas emissions by 2050. Gov. Jared Polis has said he wants more than 2 million electric cars and trucks on the roads by 2035.

But Colorado will not be able to enforce its rules if the California standards are blocked by the president.

Transportation is the leading cause of greenhouse gas emissions, and cars and trucks account for 80% of those transportation emissions. Greenhouse gases such as carbon dioxide build up in the atmosphere, trapping heat and causing global warming. Those rising temperatures are responsible for droughts, hotter summers and more intense wildfires in Colorado.

The pollution also creates ground-level ozone when nitrogen oxides and volatile organic compounds — emissions from vehicles — bake in the heat and form a brown smog over the Front Range. That ozone pollution is an ongoing challenge for the Front Range, which is in severe violation of federal air quality standards. It also makes people sick.

Electric cars have proven to be popular in Colorado.

Electric vehicles made up 25.3% of new vehicles sold in the state in the third quarter of 2024, placing Colorado ahead of California in EV sales. The state has also been investing in infrastructure to support the rising popularity.

The Republican rollback of California’s rules, the proposed elimination of federal tax credits for EV purchases, and tariffs on automakers throw chaos into the auto market and environmental efforts, Will Toor, executive director of the Colorado Energy Office, said last month in an interview with The Denver Post.

“There are a lot of wild cards out there,” Toor said. “It’s pretty upsetting to see a federal government that is trying to increase costs to consumers and seems very excited about creating economic disruption and chaos.”

Trump’s signing of the resolutions comes as he has pledged to revive American auto manufacturing and boost oil and gas drilling.

The move follows other steps the Trump administration has taken to roll back rules that aim to protect air and water and reduce emissions that cause climate change.

The Environmental Protection Agency on Wednesday proposed repealing rules that limit greenhouse gas emissions from power plants fueled by coal and natural gas.

Dan Becker with the Center for Biological Diversity said the signing of the resolutions was “Trump’s latest betrayal of democracy.”

“Signing this bill is a flagrant abuse of the law to reward Big Oil and Big Auto corporations at the expense of everyday people’s health and their wallets,” Becker said in a statement.

California, which has some of the nation’s worst air pollution, has been able to seek waivers for decades from the EPA, allowing it to adopt stricter emissions standards than the federal government. Other states were allowed to adopt California’s standards as an alternative to those outlined in the Clean Air Act.

In his first term, Trump revoked California’s ability to enforce its standards, but Democratic President Joe Biden reinstated it in 2022. Trump has not yet sought to revoke it again.

Republicans have long criticized those waivers and earlier this year opted to use the Congressional Review Act, a law aimed at improving congressional oversight of actions by federal agencies, to try to block the rules.

That’s despite a finding from the U.S. Government Accountability Office, a nonpartisan congressional watchdog, that California’s standards cannot legally be blocked using the Congressional Review Act. The Senate parliamentarian agreed with that finding.

And it’s the use of that Congressional Review Act that California, Colorado and other states are challenging in the lawsuit.

The Associated Press contributed to this report.

Updated 10:30 a.m. June 13, 2025: This story has been updated to clarify gas-powered cars’ contribution to greenhouse gas emissions.

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