Ben Segal
16th January 2026
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16th January 2026
In Illinois’ official ledgers the oil cleanup problem lists around 6,686 oil wells that need attention. It is a tidy number. It is also, according to our new research, just the tip of the iceberg.
A new report we co-authored with the Environmental Advocacy Center of the Bluhm Legal Clinic at the Northwestern Pritzker School of Law suggests the crisis is several times larger. We estimate that the majority of the state’s 30,000 remaining wells are likely producing little to no oil. They sit in a regulatory twilight zone: functionally dead, but legally "active” or “temporarily abandoned."
This distinction is critical. As long as a well is "active" or “temporarily abandoned,” the company isn't required to plug it or remediate the surrounding land. This means that functionally dead wells that no longer produce oil are left to pollute air and drinking water indefinitely.
Furthermore, the state is home to tens of thousands of previously plugged wells that are not monitored, despite the fact that older plugs are known to fail.
We calculate that Illinois is sleepwalking into a $1 billion-plus liability. And this is a debt that won't be paid by the fossil fuel companies that took the profit, but by taxpayers and communities left with the mess.
How does a state lose track of tens of thousands of wells? It failed to collect the data in the first place.
Unlike most major oil-producing states, Illinois does not require companies to report how much oil individual wells produce. Without this data, it is impossible tell whether a well is actually producing anything. An unscrupulous company wishing to avoid or delay clean up need only operate a well for show when an inspector turns up, or indicate to the inspector that it is merely temporarily idling a well.
Despite being responsible for ensuring well cleanup, the state regulator almost never enforces plugging. In fact, when we asked the agency said it could not cite a single instance in the past two years in which it has enforced a well-plugging order.
Crucially, this lack of enforcement keeps the wells tradable. In a pattern seen across the U.S., operators use 'active' status as legal cover to sell aging wells whose clean up costs outweigh the value of the revenues they can produce to smaller companies designed to go bankrupt. This maneuver lets the original owners wash their hands of the liability. When the new owner folds, the well is ‘orphaned’, leaving the cleanup to the state.
For the industry, this is a calculated exploitation of weak rules that amounts to a massive ongoing theft of public subsidy. It allows companies to keep the profits for themselves while leaving the toxic risks and cleanup costs to the public.
This isn't just an Illinois story; it is a national business model. The zombie wells crisis is not an unfortunate oversight. It is a deliberate financial strategy enabled by weak regulation and insufficient oversight.
At ClientEarth, we are dismantling this strategy from multiple angles. In Illinois, we are exposing the regulatory gaps that allowed a billion-dollar environmental disaster to balloon in secret. In Colorado, we are in court, suing companies to hold them accountable for orphaning zombie wells.
Our goal is accountability. If fossil fuel companies can erase their cleanup costs from their balance sheets, they are operating on a subsidy paid for by the health and finances of local communities.
For Illinois, the solution is straightforward. It requires no new technology, merely administrative backbone. Our report provides a common-sense roadmap to transform the state from a cautionary tale into a national blueprint.
Among the key reforms are basic steps every oil and gas producing state should take: require operators to report production data; enforce the laws already on the books; and raise security deposits to cover the actual cost of cleanup.
By closing these loopholes, governments can protect their citizens and their balance sheets in one stroke. Illinois has the tools to defuse this billion-dollar time bomb. Now, it just needs to use them.
Find out more about this issue by reading the full report here.
Since Illinois does not require operators to report how much oil or gas each well is producing, our research had to dig deeper. We analyzed public records, filed FOIA requests, and examined industry transfer patterns. By looking at the age of the wells, the lack of activity, and the financial state of the operators, we were able to estimate that the majority of the state’s allegedly active wells are likely no longer economically viable or are otherwise at high risk of being ‘orphaned’ prior to clean up.
Unplugged wells release toxic chemicals including benzene, arsenic, and hydrogen sulfide, which are known to cause cancer. They also emit methane, a potent greenhouse gas; in 2018 alone, abandoned wells in the U.S. emitted methane equivalent to the CO2 produced by 2 million cars. Locally, these wells threaten to contaminate soil and groundwater, posing direct risks to nearby communities.
In theory, oil companies are supposed to pay. However, Illinois law is rife with loopholes and its regulator consistently fails to enforce the laws on the books. For example, many states require all well operators to post bonds (essentially security deposits) that regulators can collect to cover cleanup costs in the event that company fails to do so. Illinois only requires bonds of some of its operators, and it allows those operators from whom a bond is required to post bonds that do not begin to adequately cover expected clean up costs. Indeed, Illinois allows companies to post bonds as low as $1,000 per well, even though the actual cost to plug a well is often $40,000 or more.
Without data to prove otherwise, operators can classify a well as "active" even if it produces little to no oil. This creates a loophole where operators keep wells nominally “active” or “temporarily abandoned” to avoid the high cost of plugging them.
To avoid clean up costs, operators frequently transfer aging, depleted wells to small, undercapitalized destined-for-bankruptcy companies. These smaller entities then delay clean up as long as possible, siphon off what little revenue can be generated, and line the pockets of their executives. Then they go bankrupt, "orphaning" the wells and leaving the state with the bill for cleaning them up.
No. While Illinois has particularly weak transparency laws regarding production data, the problem is a national crisis. Across the U.S., aging wells are frequently transferred from major oil corporations to smaller, underfunded companies that ultimately go bankrupt. This crisis of clean up avoidance includes, but goes beyond, the use of bankruptcy to defraud governments; companies have an arsenal of maneuvers to delay and dodge obligations, and we see companies regularly employ them with callous disregard for the health and environmental harms they force onto their neighbors.
In 2025, Illinois did pass SB 2463 to address some of these issues, but the new rules are deeply inadequate. The state knows from experience that cleaning up a single well typically costs around $40,000. Despite this, the new law allows operators to post bonds of just $10,000, and sometimes as little as $1,000 or even $0 for certain operators. This math guarantees that if a company fails, taxpayers will foot the bill for the shortfall. Raising bond amounts to cover the actual cost of cleanup is one of the most effective ways to protect public money, but it is a reform the oil and gas industry fights hard to prevent. Furthermore, SB 2463 does nothing to address the State’s woeful data collection and transparency problems, nor does it address a whole range of other issues this report details.
