There are nearly 30,000 idle wells in California, and half of them have not been operated in 15 years or more.
California's state petroleum regulators announced new rules last Friday regarding the handling of idle oil and gas wells.
Regulations set to take effect April 1 require oil producers to test idle wells to prevent leaks, provide engineering analyses for wells unused for 15 years or longer and file long-term plans for managing idle wells, among other measures, The Bakersfield Californian has reported.
Idle wells, defined as those left unused for two years or more, are a concern mainly because well pipes can deteriorate, allowing petroleum or other contaminants to migrate into underground sources of drinking water. Such wells may need to be permanently sealed.
There are nearly 30,000 idle wells in California, and half of them have not been operated in 15 years or more, according to the state Department of Conservation, which announced the new rules. It said the regulations result from the passage of Assembly Bill 2729, which was signed into law in 2016.
The state has spent $29.5 million permanently sealing 1,400 "orphan" wells left behind by insolvent owners. AB 2729 increases fees on well operators — up to $1,500 for each well idle 20 years or more.