Colorado natural gas flaring occurs out of public view

The volume of gas that is flared at oil and gas sites in Colorado has declined in recent years, but environmental groups warn that it still continues with alarming frequency, despite the state’s official ban on the practice. The widespread use of “enclosed” flares, which visually obscure the burning of gas, has allowed flaring to continue while simultaneously creating the common perception that the problem has been resolved, advocates warn.

In 2020, Colorado became the first state in the country to ban “routine” flaring and venting of gas, and regulations took effect the following year. Prior to those rules, producers could flare or vent unwanted or excess gas, a practice that was especially common in areas where pipeline infrastructure was less developed. In Texas, such routine flaring occurs constantly, unimpeded by state and federal regulation.

The regulations in Colorado allowed the state to claim the mantle of an environmental leader. The International Energy Agency specifically cited Colorado as one of a handful of jurisdictions globally that is making strides on reducing flaring rates, pointing to the ban on routine flaring. The state’s political leaders also consistently hail the regulatory regime as a model for federal regulations.

“Colorado has led the nation in limiting methane emissions from the oil and gas industry, and has long recognised the harm caused by routine venting and flaring,” Colorado Senator Michael Bennet said when the federal Bureau of Land Management introduced new methane regulations in March.

Even the industry points to the state’s regulation as evidence that oil and gas production is conducted with high standards. The Colorado Oil and Gas Association (COGA), an industry lobbying group, says the “oil and natural gas molecules produced in Colorado are among the cleanest in the world.” They’ve branded gas from the state as “The Colorado Molecule.”

While flaring is done in Colorado with less frequency compared to other regions, environmental groups warn that it is still a common occurrence across the state.

“I will sometimes hear from officials at the state that Colorado has eliminated flaring, and that’s simply not true,” Andrew Klooster, an advocate with the environmental NGO Earthworks, told Gas Outlook.

There are exceptions to the flaring prohibition. Companies can apply for variances, allowing them to flare under certain conditions. It is allowed to maintain safety. Flaring is also permissible during the drilling and the hydraulic fracturing process, when enormous volumes of gas surge out of the ground.

There is one sharp difference compared to many other oil and gas basins. Instead of flare stacks with tall flames, oil and gas sites in Colorado have increasingly turned to “enclosed combustion devices,” or ECDs. ECDs are tall cylindrical stacks, akin to a typical flare stack, but the combustion of gas occurs inside at the bottom of the structure. As a result, the flame is enclosed behind a wall, hidden from public view. To the casual observer, ECDs make it appear as if there is no flaring taking place.

“We’re at the point now where I don’t know that I have seen in the last couple of years any traditional flares on any upstream oil and gas facilities in Colorado,” Klooster said. “They are all enclosed flares.”

That offers a striking contrast to places like the Permian basin, where enormous flames, shooting into the sky, are commonplace.

The problem for environmental advocates is that, despite the common perception that flaring has been banned in the state, it is still occurring under the guise of ECDs. Enclosed gas flares can even complicate detection by satellites searching for a heat signature, as The Guardian reported in early May.

Ultimately, enclosed flares are sources of pollution similar to conventional flares. And as with flaring that occurs pretty much everywhere, they do not always burn as cleanly as advertised.

Klooster uses optical gas imaging (OGI) cameras, which can visually detect plumes of hydrocarbon pollution, including methane, that are not visible to the naked eye.

He has recorded dozens of videos of enclosed flares in the past few years, many of which contain visual evidence that suggest the ECDs are not operating at the efficiency levels promised by their operators. Flares are supposed to burn 95 to 98 percent of the gas that passes through their stacks. Incomplete combustion results in unburned methane emitted into the atmosphere, along with a variety of other air pollutants. As a result, they contribute to both climate change and poor air quality for local residents living nearby.

“I’ve observed and documented many, many instances of inefficient combustion in these ECDs,” Klooster said.

OGI cameras cannot measure the quantity of unburned hydrocarbons, so it’s difficult to say with any precision at what level of efficiency the flares are operating. But Klooster says the video evidence, recorded at many sites over several years, raises serious questions about how much pollution is coming from oil and gas sites — and also raises red flags about the quality of the regulatory regime.

Klooster has filed many complaints with Colorado regulators, but that hasn’t resulted in decisive action from the state. Instead, regulators call up the oil or gas company, relay the complaint to them and ask for information. Klooster said the operators sometimes clean a piece of equipment, or fix some technical issue, which may help resolve the problem. But often, they respond to state officials and say that everything is operating smoothly.

In response to questions from Gas Outlook, Megan Castle, a spokesperson for the Colorado Energy and Carbon Management Commission, which regulates the industry, said: “Minor venting and flaring may occur during drilling and completions operations and during upset conditions, but must be reported and must be limited.” The term “upset conditions” refers to an unexpected equipment malfunction or failure. She said that wells that are unable to connect to a gathering pipeline system and are not able to use the gas on site “should be plugged.”

She pointed to state data that shows a dramatic decline in flaring and venting after the regulations went into effect, evidence that the rules are having an impact. In 2023, the industry flared and vented 671 million cubic feet of gas, down from 2,589 million cubic feet in 2021.

But regulatory oversight largely boils down to “self-policing and self-reporting,” Klooster said.

“A lot of the rules and regulations in Colorado are still for the most part being implemented by operators themselves and then reported back to the state,” he said. He added that the existence of regulations lends the industry a “social license” and the perception of compliance. “But there’s not a whole lot of oversight to ensure that that compliance is actually occurring on the ground, other than what the operators are telling us.”

State regulations require new ECDs to be inspected and tested for their efficiency once, and then again every five years. Such infrequent inspections “do not inspire confidence,” Klooster said. 

Another concern is that the use of ECDs, instead of conventional flares, means that the public largely does not understand the extent of the problem. That creates “a larger narrative about how clean the industry is in Colorado because of the rules on paper,” he said.

“There is a lot riding on that perception both for the state and for the industry because they love to point to Colorado as the gold standard.”

The Colorado Oil and Gas Association did not respond to questions from Gas Outlook.

A ‘system-wide issue’

But even with tests of ECDs occurring so intermittently, some flares are still failing inspections.

“What’s underpinning oil and gas air quality regulation in a lot of states, and even on the national level, is this presumption that these enclosed flares are controlling emissions effectively at all times,” Jeremy Nichols, a senior advocate at the Center for Biological Diversity, an environmental NGO, told Gas Outlook. “In Colorado, what we’re seeing is that is not the case.”

The regulatory agencies and the rules on the industry take for granted that flares are operating at the purported 95 to 98 percent efficiency rate, he noted.

“We’re increasingly coming across testing data, like actual testing data conducted not only by companies but by state and federal inspectors, that demonstrates that in many cases these flares are not meeting anywhere near the level of control efficiency,” Nichols said.

He pointed to the example of a 2020 inspection of a compressor station owned by Rocky Mountain Midstream. The flare was supposed to achieve a 98 percent efficiency rate, but failed the test, only burning gas at a 69.6 percent rate. In another case, a 2023 test of a flare associated with a storage tank owned by a company called Wexpro also failed, reporting a 67 percent efficiency rate. In both cases, the sites were emitting unburned methane, and likely an array of toxic air pollutants, for an unknown period of time before the inspection.

In many instances, the fixes appear to be simple — the company cleans some equipment, or adjusts the pilot light. Then they are inspected again.

But because the ECDs are only inspected every five years, how effective they are at any given moment is almost entirely unknown.

“The problem with the [95 to 98 percent] efficiency metric is that it’s a target, and it’s something that is aspired to,” Nichols said. “But there’s not a whole lot of data, especially from the field in Colorado, to really determine whether or not they’re actually achieving that efficiency.”

The Center for Biological Diversity has begun filing legal challenges to air permits issued by Colorado for oil and gas drilling projects, arguing that the examples of flares failing inspections should raise sufficient concerns to give regulators pause. In addition, because monitoring and inspections are limited and infrequent, state agencies should not take the oil and gas industry at its word that flares are operating properly.

Not gaining much traction with Colorado regulators, the NGO turned to the federal Environmental Protection Agency. The EPA has ruled partially in the group’s favour two times this year, reprimanding the Colorado Department of Public Health and Environment (CDPHE), the air quality regulator, stating that “[i]t is unclear…how the monitoring requirements assure that the [flares] continually achieve the specific 95 percent control efficiency required in the Permits.”

The Center for Biological Diversity celebrated the win, stating that it “calls into question the effectiveness of pollution controls.

“We’re building, I think, a body of evidence that really does indicate that it’s a complete facade to claim that these rules are working. There simply is not the checks and balances in place to verify that these rules are actually doing what they’re supposed to be doing,” Nichols said. “And if it’s happening in Colorado, we know that it’s happening in other states as well.”

In response to questions from Gas Outlook, Zachary Aedo, a spokesperson for CDPHE, downplayed the significance of the EPA rulings. He said the permits in question remain in effect, and operators still have to abide by their conditions.

“The EPA did not object to flares achieving 98% efficiency, but rather directed the division to evaluate the permit record and consider whether the permits include adequate monitoring requirements for a narrow set of enclosed combustion devices,” he said. “The division’s experts continue to review the EPA’s recent decision and any additional impact it may have.”

But Nichols believes the problem is not narrow at all.

“We’re steadily exposing this this as a system-wide problem,” Nichols said, arguing that there needs to be a “reckoning” with how the state regulates the industry.

“These aren’t anomalous permits. This is the underpinning of the state’s whole regulatory framework,” he said. “I think it’s just it’s the house of cards.”