Uncapped Gas Wells in Colorado
By Brian Stern
The Numbers: A Pervasive Legacy
There are millions of abandoned oil and gas wells nationwide. A subset of these is “orphaned,” meaning they are unplugged and have no financially responsible owner. Orphaned wells often arise when large corporations offload low-producing wells to operators filing for bankruptcy or to smaller operators who lack the financial resources to properly plug the wells.
Colorado’s oil and gas legacy is vast — and increasingly dangerous. The Colorado Energy and Carbon Management Commission (ECMC) Daily Activity Dashboard lists roughly 45,737 active wells, 36,073 producing wells, and 54,249 “plugged and abandoned” wells. Colorado recognizes 2428 orphaned oil & gas sites and 1400 orphaned wells as of 2024 subject to upward revision. According to the U.S. Geological Survey (USGS), in a conservative estimate, there are over 117,000 documented unplugged orphaned wells across 27 states.
Reports suggest the true number of undocumented orphaned wells in Colorado and Nationwide are higher with the inaccuracy created by the oil and gas sector’s inadequate reporting, and the regulatory bodies inadequate oversight. Moreover, the number of abandoned and orphaned wells are certain to grow.
Capping Efforts, Funding Sources, and Expenditures
Colorado’s Orphaned Well Program began in 1990. It closes orphaned sites by plugging wells and decommissioning old flowlines; removing production equipment and debris; investigating and remediating soil and groundwater impacts; installing safety equipment such as fences, signs, and locks or tags, and reclaiming well pads, remote production sites, and access roads. The State of Colorado groups orphaned oil and gas sites by location ID into low, medium, and high priority categories based on multiple risk factors, including population density and urbanization; environmental factors; years in service; active and historic spills; stormwater issues; noxious weeds; wildlife, livestock, or vegetation impacts; surface equipment; bradenhead pressure; mechanical integrity test data; and any documented history of venting or leaking.
Economically, the numbers are grim. In Colorado the average cost to decommission a single well site is $92,710 and the average cost to plug a well is $52,141. For complex sites the cost can triple. The federal orphan well funding, established under the Biden Infrastructure Investment and Jobs Act (IIJA) of 2021, has provided billions of dollars in grants to states and Tribes. Colorado in 2022 received an initial grant of $25 million. In 2024, Colorado was granted $25 million for work in 2025 and 2026. In 2024. Colorado applied for another $29 million for the following years. In addition to the federal money, Colorado established the Orphan Wells Mitigation Enterprise (OWME), which is an industry-funded program. This enterprise is financed by an annual flat fee of $115 per well paid by all oil and gas operators. This fee generates approximately $10 million annually, with the explicit purpose of paying for the plugging and remediation of orphaned and marginal wells. Nonetheless, the total estimated cost of decommissioning sites and plugging all documented orphaned wells exceeds the available funds by billions of dollars.
Despite tens of millions of expenditures, our Orphan Well Program plugged only 94 wells in FY2024. In 2023, Colorado’s Orphaned Well Program spent $10.2 million to plug 61 wells. At this pace, it will take more than 15 years just to clear the backlog of currently known orphan wells — even if new ones were not added. Yet, each year the number of orphaned wells and sites needing attention increases: the number of orphaned wells continues to climb faster than the rate of remediation. Last year the number of sites needing work grew from 1411 to 1897. The number of orphaned wells grew from 648 to 948. There is clearly an issue with the oil and gas industry itself, not the earnest work of taxpayers’ dollars.
The State provides an impressive volume of oil and gas well data. Yet beneath this veneer of transparency lies a troubling uncertainty. The state admits it does not truly know which wells are leaking methane, which “plugged and abandoned” wells may or may not have an active operator of record, there is no specific program dedicated to tracking these wells after plugging, which sites are securely sealed, nor does it maintain a program to ensure abandoned wells remain sealed. Once a well is labeled “plugged and abandoned,” oversight largely ends. ECMC only responds if integrity issues appear. In practice, that means tens of thousands of wells across Colorado are unmonitored — and potentially leaking methane, benzene, and other harmful gases into air and groundwater. This reactive approach almost guarantees that leaks go undetected until they become environmental or public safety hazards. This all creates a ticking environmental and public-health time bomb, and skyrocketing costs.
The state’s Orphan Well Program (OWP) operates only after a well loses its responsible operator. Accordingly, 12,000 “active but not producing” wells remain outside the scope of orphan well oversight and sit idle while potential emitting methane. Colorado’s 25,000 inspections this year are commendable, but without a targeted methane monitoring program — one that integrates remote sensing, continuous leak detection, and annual verification of plugged wells — the state cannot claim to have a full grasp on the scope of methane emissions.
For a state that prides itself on leadership in climate and energy reform, this oversight gap is more than a bureaucratic flaw. It’s a climate liability. Colorado should strengthen its well integrity program to ensure every abandoned site is accounted for, verified, and monitored for methane leakage. Transparency is a start— but vigilance must follow. While Colorado’s Regulation 7 has led the nation in setting methane emission standards, it does not extend to long-term monitoring of plugged or abandoned wells. Nor is the permitting of new wells taking into account the growing legacy of problems.
Economic Costs and Limited Benefits of Oil and Gas
The oil and gas industry is often portrayed as a vital economic pillar. The oil and gas industry’s contribution to jobs, tax revenue, and the state's overall economy are not nearly as significant as the industry would have Coloradans believe. The fossil fuel industry imposes substantial costs that must be objectively assessed against its benefits.
The oil and gas industry (even when including pipeline construction, transportation industries and other support industries) represents just 1.8% of total wages in the state, represents just 3.3% of Colorado’s GDP and 0.7% of total employment. In comparison, manufacturing contributed twice as much to GDP (6.6%), and the Professional and Business Services sector contributed about 5 times as much (15.5%). The math is simple: the industry’s economic footprint is small, but its environmental debt is enormous.
Even the industry’s much-touted property taxes account for only 3.5% of total local school funding, and 70% of school districts receive less than 1% from oil and gas. A portion of local, federal and state tax revenue also goes directly toward regulating the industry, cleaning up pollution or compensating for losses caused by development. State audits and independent analyses have found that, after accounting for exemptions and credits, the industry pays only a fraction of its potential tax liability. The revenue, jobs, and other perceived economic benefits from the oil and gas industry do not compensate for lower property values for your neighbors impacted by oil and gas drilling sites and uncapped wells. The revenue from taxes and permit fees is insufficient to cover eventual cleanup costs. This creates a scenario where the public, through funding state and federal programs, is ultimately forced to bear the financial burden to clean up the mess of a profitable industry. In economic jargon, the costs of the oil and gas industry’s environmental and social impacts are not internalized by the industry; instead, those costs are externalized to become a burden to citizens and taxpayers. A fundamental economic reality must be underscored: the short-term benefits of extraction do not fully account for the long-term liabilities.
In the final analysis, the Colorado oil and gas industry is of limited significance to the state’s economy, particularly when weighed against current and legacy costs. The oil is being taken out of state, the profits are being taken out of state and leaving billions in damages. All of this while the U.S. federal government subsidizes the production of oil, gas, and coal by at least 34.8 billion per year. The big ugly Bill of 2025 added $4 billion in subsidies to fossil fuels including oil and gas.
Health and Environmental Costs
Uncapped and orphaned wells pose a direct threat to public health and the environment. These oil and gas wells are a significant source of methane emissions. Research in Colorado has already detected abandoned wells emitting hundreds of grams of methane per hour (on average 586 g CH₄ hr⁻¹) over 70 times the U.S. “plugged” average. Estimates suggest millions of tons of methane are emitted annually from abandoned wells nationwide. These abundant number of “small leaks” counts for most of the oil and gas industry’s methane pollution.
Methane is a potent greenhouse gas, with a global warming potential over 20 years that is 80 times greater than carbon dioxide. Methane from global emissions is a major driver, accounting for almost one-third of the global warming we are currently experiencing. Global warming is already causing billions of dollars of damage to Colorado, harming our agriculture and recreation industries, and creating climate-caused disasters which alone have cost the state between $20 billion and $50 billion since 1980. A study from the Colorado Fiscal Institute estimates that pollution from oil and gas operations in the state will cause over $13 billion in damage between 2020 and 2030. On an annual basis, that cost is 1.5 times the total taxes and fees oil and gas brings to Colorado. As impressive and distressing as these costs are, economic costs are usually underestimated. Cutting methane emissions is one of the greatest opportunities for near-term success in addressing climate change.
Methane is not the only toxic gas. Oil and gas wells and equipment leak volatile organic compounds (VOCs), methane, benzene (a known carcinogen), nitrogen oxides (NOx), fine particulate matter (PM2.5), other air pollutants, and creates ozone pollution all contributing to respiratory and cardiovascular problems, asthma and heart disease, and cancer. The oil and gas industry in Colorado is worsening asthma and heart disease —affecting more than 32,000 Colorado children annually, according to a study by the Colorado Department of Public Health and Environment (CDPHE). Exposure can cause headaches, nausea, and nosebleeds. Residents living near multi-well sites reported a higher frequency of acute upper respiratory and lower respiratory symptoms.
According to the Colorado Energy and Carbon Management Commission, hydraulic fracturing or “fracking,” which has occurred in approximately 90% of oil and gas wells in Colorado since the 1970s, uses about an average of 2 to 8 million gallons of water per well, mostly during initial drilling and completion. Newer studies report that with current fracking techniques each well consumes about 17 million gallons of water. Even under the lower estimates, the volume of water required annually for new oil and gas development is enough to serve up to 296,100 people.
Oil and gas development can also impact surface and ground water quality through stormwater runoff and spills, surface spills, leaking waste pits, or poor disposal practices. Studies have found significantly higher levels of arsenic, selenium, strontium, and total dissolved solids (TDS) in water wells less than 3 km from shale-gas. A 2017 Colorado School of Public Health study found that children living within 2,000 feet of high-intensity oil and gas development were more likely to develop acute lymphocytic leukemia. Leaking oil and gas wells contaminate ground water with oil, methane, saline water, and other undisclosed fluids, posing a risk to drinking water supplies. The industry has spectacularly failed to report on the chemicals they are using, despite the law’s requirement for them to do so. The industry continues with reckless abandonment to apply for permits adjacent to schools, residences, water supplies, and even Superfund Hazardous waste sites. An example is pending applications for drilling permits next to the Aurora Reservoir and Lowry Superfund Site.
Uncapped wells present physical dangers, including the risk of explosions from accumulated gas. Caution should be exercised around them, and public health and safety demands that they be plugged as soon as possible. The lack of direct, systematic field verification leaves tens of thousands of legacy wells effectively an ongoing hazard. Every dollar spent proactively sealing and monitoring wells prevents exponentially higher costs in climate and health impacts down the road. Every well not drilled is prevention against further health, environmental and economic costs.
It is only going to get worse
The number of orphaned wells in Colorado has more than quadrupled since 2020 and is expected to grow. In the past six years from 2019 to2024, there were 7712 oil & gas drilling permits approved, on average 1,285 new oil & gas wells per year. With more drilling there will be more abandoned and orphaned wells. With the current federal administration’s push for deregulation and more drilling, we can expect even more oil and gas wells to be abandoned. With increased efficiency and competition from solar and wind, we can expect even more oil and gas wells to be abandoned. Forcing Colorado communities to bear the costs is only due to historical habits which have outlasted their usefulness, undue influence of lobbying, greenwashing, and disinformation.
Conclusion
There is a high cost from oil and gas production and abandonment of sites and wells. Despite record profits, the industry is abandoning wells at an increasing rate. The path forward is not mysterious — only underprioritized. No more drilling until the current mess is cleaned up. Colorado must create a dedicated well-integrity monitoring program, require periodic methane testing of all plugged wells, invest in remote-sensing technologies and public mapping tools that clearly identify wells of concern. The state must enforce financial assurances that compel companies — not taxpayers — to pay for long-term containment. There must be mandatory financial assurance bonds that cover full decommissioning costs. In a state that prides itself on innovation and environmental leadership, allowing thousands of potential methane emitters to go unchecked is indefensible. Oil and gas operators have profited for decades; now they must be held accountable for their legacy.
As the oil and gas industry in Colorado declines due to market forces, regulation, or a combination of these, we can expect the economy to evolve and develop to accommodate these changes. The economy has shown that over time it can absorb large changes. Colorado can come together to find a solution that will support the communities that need change. Clean air, safe water, and a stable climate are not luxuries — they are the basic costs of doing business. Colorado must act decisively: plug the leaks, enforce accountability, and invest now — before the cost of inaction rises beyond what any budget, or any community, can bear.
The current standard that society demands is simply that industrial production must be done without unmitigated harm, must be done to the best industry standards, and must compete fairly without externalizing their costs, foisting their costs onto the rest of society. Without strict requirements the oil and gas industry’s default is to abandon wells leaving us to clean up the mess. Every child knows the precept: clean up your mess before drilling for more. The simple answer: a temporary moratorium on new drilling permits until the orphan well backlog is cleared.
Brian Stern is a lifelong environmentalist, environmental advocate, with an undergraduate in environmental politics and attorney of environmental law
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