BAKERSFIELD, Calif. — Regulators say they're making attempts to stop persistent oil spills in the Central Valley.

A Kern County oil field is said to have been flowing off and on for the last 16 years and may have spilled more than 50 million gallons. The problem stemmed from a production method used in the oil field, just west of Bakersfield.

Reports say state regulators have now served Chevron with a notice of violation, ordering it to stop surface flows at another site.

According to Chevron, there has been no harm to water or wildlife.