LOS ANGELES — More than 1,000 oil and gas operators violated a recent California law aimed at cleaning up the state’s idle wells, which pose a threat to the environment, air quality and public health, records show.

The law, A.B.1866, strengthened requirements for operators to either pay a fee or submit a management plan for each of their idle wells — oil and gas wells that are no longer producing — by May 1. Compared to prior years, more operators, especially larger ones, submitted idle well management plans in 2025 instead of paying the increased fees. As a result, most of California’s idle wells are “covered” by these plans, which vary in length of time from 1 to 8 years.

However, according to records from the California Geologic Energy Management Division, or CalGEM, approximately 1,085 operators did not pay the fee or submit a valid plan by the deadline.

“It’s alarming that so many oil companies have broken the law meant to accelerate the cleanup of the messes they’ve caused. These companies have been raking in massive profits in California for generations,” said Cooper Kass, an attorney at the Center for Biological Diversity’s Climate Law Institute. “The new law was a step in the right direction, but these records show regulators need to do more to hold the oil industry accountable and protect frontline communities.”

More than 1,000 noncompliant drillers are responsible for nearly 3,500 idle wells, most of them located in Kern, Los Angeles, Santa Barbara and Ventura counties. These wells can leak methane, a powerful greenhouse gas, and harmful toxins including benzene, toluene and xylene, which are linked to increased risks of asthma, cancer, heart disease and other health problems. Both active and idle wells can also threaten water supplies.

Most of these noncompliant operators have wells on CalGEM’s 2023 Likely Orphan List, a list of wells that the agency has determined lack a solvent operator to conduct cleanup. Some companies don’t exist anymore, others have declared bankruptcy and a portion of violators were individuals who operated a single well decades ago and may be deceased. At the same time, a number of noncompliant operators are still in business.

“When operators disappear, their dangerous unplugged idle wells don’t go with them,” said Kass. “State regulators must fully enforce the law and do everything possible to speed up well cleanup so that Californians aren’t left to foot the bill.”

In California, an idle well can cost $220,000 to $900,000 to plug. According to a 2023 Carbon Tracker report, it could cost $21.5 billion to clean up all the state’s oil sites. At the time of the report, oil and gas companies had only posted $106 million in bonds — less than 1% of what is needed — for plugging and abandonment of all their wells. If regulators don’t recoup these funds from the industry, Californians will have to pay to clean up the wells.

This deficit underscores the need for CalGEM to use the authority given to it by the legislature and require operators to post bonds that cover the full cost of plugging and abandonment. That way if an operator goes bankrupt or ceases to exist, the state can use bonds, not taxpayer funds, to pay for well cleanup.

“The longer regulators wait, the higher the risk for the public and the environment,” said Kass. “Oil production in California has declined more than 70% since 1985. It has reached the end of its lifecycle. Urgent action is needed to clean up these wells and protect the air we breathe and the water we drink.”