​​​​Idle Well Program

​​​​​​​​​​​​​​​​​​​​​​​​In California, an idle well is a well that has not been used for two years or more and has not yet been properly plugged and abandoned (sealed and closed). Plugging and abandonment involves permanently ​sealing the well with a cement plug to isolate the hydrocarbon-bearing formation from water sources and prevent leakage to the surface. If a well is not properly sealed and closed, it may provide a pathway for hydrocarbons or other contaminants to migrate into drinking water or to the surface. Improved reporting shows there are approximately 35,000 wells in California categorized as idle. 

The Geologic Energy Management Division (CalGEM) revised its idle well ​regulations ​in April 2019 to create far more stringent testing requirements that better protect public safety and the environment from the potential threats posed by idle wells. The regulations require idle wells to be tested and, if necessary, repaired, or permanently sealed and closed.

If an operator becomes insolvent or deserts their idle wells, responsibility for permanently sealing and closing these wells may fall to the State. Since 1977, CalGEM has plugged and abandoned about 1,400 wells at a cost of $29.5 million. To reduce the number of idle wells for which the State may become responsible, legislative and regulatory changes have been made to create incentives for operators to manage and eliminate their idle wells by entering into Idle Well Management Plans (IWMPs). If an operator does not have an IWMP, the annual idle well fees the operator must pay for each of the operator’s idle wells have been increased to reflect the potential costs associated with those wells. The fees are deposited into the Hazardous and Idle-Deserted Well Abatement Fund to help fund the permanent sealing and closure of deserted wells.

Idle Well, Cat Canyon Oil Field, Santa Barbara County


Inactive and deserted oil and gas wells that are not maintained can pose threats to groundwater and public safety. CalGEM has taken multiple steps to mitigate such potential hazards with ground-breaking legislation (Assembly Bill 2729, Williams, 2016) and development of rigorous regulations. There are incentives for operators to file Idle Well Management Plans for either plugging and abandoning long-term idle wells or returning them to production. Also, idle well fees have been increased to help encourage operators to address such wells in their inventories.

The 2018 report details that:

    • Wells are now being plugged before they become a problem. 1,234 idle wells, of which 968 were long-term idle wells, were plugged and abandoned (permanently sealed and closed).
    • CalGEM collected $4.3 million in idle well fees, funds that are available to remediate hazardous well conditions to protect public health and the environment.
    • Operators are complying. They filed 76 Idle Well Management Plans, leading to the elimination of 988 long-term idle wells.

Request the downloada​ble version: Department of Conservation Idle Well Program Report, January 1, 2018−December 31, 2018​ (PDF)

CalGEM issued Final Orders to Plug and Abandon more than four dozen idle wells to 14 operators, in response to unpaid idle well fees in 2018. CalGEM sent 12 Notices of Cancellation to operators who failed to comply with the terms of their 2018 Idle Well Management Plans. Future enforcement will expand the focus to compliance with updated idle well regulations (2019) in addition to statutory requirements.

Idle Well Definitions

For Operators