Toxic wastewater from oil fields keeps pouring out of the ground. Oklahoma regulators failed to stop it.

This article is co-published with ProPublica ; it was created as part of the Local Reporting Network in partnership with The Frontier .

In January 2020, Danny Ray started a complicated job with the Oklahoma agency that regulates oil and gas. The petroleum engineer who’d spent more than 40 years in the oil fields had been hired to help address a spreading problem, one that state regulators did not fully understand.

The year prior, toxic water had poured out of the ground — thousands of gallons per day — for months near the small town of Kingfisher, spreading across acres of farmland, killing crops and trees.

Such pollution events were not new, but they were occurring with increasing frequency across the state. By the time Ray joined the Oklahoma Corporation Commission, the incidents