Oil and gas drilling activity in Colorado was down in 2025, leading to fewer total air emissions — even as emissions for each new well are projected to rise, according to a report from the state Energy and Carbon Management Commission.
The commission approved 48 oil and gas development plans last year — 20% fewer than in 2024 — for drilling 801 wells on 81 sites, the commission’s annual cumulative impacts report said. In 2024, 1,168 new wells were approved.
The estimated emissions for widespread air pollutants from these operations was down 30%, to 12,676 tons, compared with 2024 activity. Those pollutants include nitrogen oxides, or NOx, carbon monoxide, methane, ethane and volatile organic compounds.
The single largest emission was carbon dioxide, a greenhouse gas, at 867,047 tons, a 21% drop from 2024.
The ECMC attributed the drop in drilling plans and wells to new rules that started at the end of 2025, leading to a two-month pause in new applications.
The drop in total emissions in 2025 is “an outlier,” likely due to a rush to get new permits in 2025 and the hiatus in new applications, Heidi Leathwood, a climate policy analyst with the environmental group 350 Colorado, said in an email.
The bulk of the new drilling in the state was along the Front Range with 32 drilling plans on 44 sites with a total of 695 wells — 88% of all the wells drilled in Colorado.
The second most active area was the Western Slope, with seven drilling plans for 67 wells, followed by the Eastern Plains with five plans and 14 wells.
Methane emissions from Front Range drilling, fracking tripled
One trend across all the oil and gas basins is that the emissions per well are rising. This is a particular concern along the Front Range, which is the most heavily populated area and is plagued by ozone pollution.
Nine Front Range counties were designated as a “severe” nonattainment area for ozone by the federal EPA for exceeding health standards for the corrosive gas — created by NOx and volatile organic chemicals reacting with the sunlight.
NOx emissions per well on the Front Range during fracking and drilling have increased 23% in the past three years to 6.5 tons per well in 2025.
Volatile organic chemical emissions per well on the Front Range increased about 10% to 1.12 tons compared with 2024 emissions.
Statewide 2025 methane emissions were up 27%, to 1,120 tons, even with fewer drilling plans approved. This increase was driven mainly by Front Range oil and gas developments, the report said.
Methane emissions from fracking and drilling on the Front Range more than tripled compared with 2024 to 1.15 metric tons, with emissions from onsite engines up almost tenfold.
There are several reasons for the per-well increases in emissions, including larger projects and longer horizontal wells, according to the ECMC.
The Front Range area tends to favor large pads averaging 13 to 18 acres of construction disturbance, which then serve multiple horizontal wells.
And those wells are getting longer, some extending 3 or more miles. In the past five years, the average length of wells has increased to 19,500 feet in 2025 from 18,500 feet in 2021.
The ECMC said the increasing length of wells is “likely the controlling factor on how long drilling or completion rigs must be on site … and a major influence on per-well emissions.”
Operators must comply with a set of regulations aimed at reducing emissions and often agree to best management practices that go beyond the rules, such as committing to using nonpolluting electric drill rigs.
The data, however, shows that they may not be enough.
“These trends indicate that increases in electric drilling and other emissions reduction strategies in the Front Range are potentially being offset or outpaced by operational and/or siting challenges and are not resulting in appreciable emissions reductions,” the report said.
Still, the planned operations are not expected to contribute an excess of the pollutants that create ozone in the nonattainment area, the report said.
The state Air Pollution Control Division said in 2025 that nearly all operators in the nonattainment area are compliant or overcompliant with NOx intensity targets, which set the permitted emissions based on a well’s output.
“We are meeting and or exceeding our NOx intensity targets,” said Lynn Granger, president of the Colorado Oil and Gas Association, an industry trade group.
Granger said overall emissions are down due to factors including investment in technologies, electric drilling rigs, continuous monitoring and better production practices.
“We’re drilling fewer wells, but we’re developing longer laterals,” Granger said. “The wells themselves are more productive, and so, yes, there could be a bit of an increase per well, but overall activity or overall emissions are down.”
Another class of pollutants — hazardous air pollutants, including benzene, formaldehyde and toluene — reached a five-year low on the Front Range at 103 pounds.
ECMC noted, however, that “locations in this operating area are generally sited closer to residences, communities and schools than other operating areas, presenting a higher risk to these communities from toxic chemical pollution.”
The highest CO2 and NOx and volatile organics emissions were observed in North Park and southwestern Colorado. The Western Slope and Eastern Plains also saw an increase in hazardous air pollutants per well.
The oil gas development plans estimate their emissions for the cumulative impact reports. Those estimates were eventually checked against actual emission by the state.
Those checks found operators tend to underestimate the emissions on carbon monoxide, NOx, and volatile organic compounds.
This discrepancy makes it difficult to assess impacts, said Natasha Leger, executive director of Paonia-based Citizens for a Healthy Community, leaving regulators with “a slow trickle of actual data.”
Recycling water used in drilling has dropped
Another area where the sector did not make progress is in its use and recycling of water for fracking. The water, with a small mixture of chemicals and sand, is pumped into wells under pressure to fracture rock and release oil and gas.
The 48 approved oil and gas development plans need an estimated 321 million barrels of fresh water or 41,279 acre-feet, about 1% of the state’s total water use. Front Range wells are the thirstiest, each one using 44,300 barrels or about 5.7 acre-feet. (An acre-foot of water can support two to four households per year.)
To reduce the need for fresh fracking water, the ECMC in April 2025 issued first-in-the-nation regulations requiring 4% of the water from oil and gas production to be recycled starting in 2026, and rising to as much as 35% by 2038.
Statewide, the percentage of recycled water planned for drilling and completing wells has steadily fallen for the past three years. The percentage of recycled water to be used in fracking slipped to 5.2% in 2025 from 11.2% in 2023.
Planned recycled water use decreased on the Western Slope, Front Range and Eastern Plains, as well as southwestern Colorado. The main contributor to the statewide decrease was on the Western Slope followed by the Front Range.
Environmental groups fault the commission’s methodology of collecting statewide and regional data for new developments, but not data on how multiple oil and gas operations impact local communities.
“We’ve been calling out since 2021 that the report does nothing to evaluate how the new OGDPs that have been approved add to the impacts from the thousands of already existing and producing wells,” 350 Colorado’s Leathwood said.