California state regulators have ordered a dozen "injection wells" in the Central Valley shut down to protect drinking water from contamination. The wells are used to dispose of wastewater from oil production.
The order comes after the discovery of more than two-thousand instances where the state authorized oil field injections into protected aquifers. In ten cases, operators voluntarily shut down. Two other operators were issued cease and desist orders.
The State Water Resources Control Board says the operators will be required to test groundwater near the oil wells to determine where there is contamination.
"The reason we have the investigative orders is to determine .... orders are about," says Jonathan Bishop, who is with the board.
The state's Environmental Protection Agency says in a separate report that the groundwater was injected with oilfield waste due to years of confusion, lax oversight and miscommunication among government regulators.