Oklahoma Oil Company Seals Disposal Well Threatening City’s Drinking Water

An Oklahoma oil and gas company has permanently sealed a disposal well that posed a significant threat to a city's drinking water supply. The Flying Monkey well, operated by BCE-Mach III Midstream Holdings LLC, was plugged on Sept. 14 after an investigation revealed it had been approved in violation of state rules. The well, located just a quarter-mile from Enid's municipal groundwater supply sites, injected toxic oil field wastewater underground. State regulations prohibit such operations within a half-mile of public water wells unless a hearing confirms safety, which did not occur in this case.

The city of Enid had filed a complaint in 2025 to revoke the well's permit, citing incorrect permit applications by the original operator, Hinkle Oil & Gas. The well had a troubled history, failing structural integrity tests five times since 2021 and reporting a leak in early July. The state gave the owner 90 days to fix the leak or plug the well permanently. The company chose the latter, sealing it with a cast iron plug and cement.

Enid city officials were unaware of the well's closure until informed by reporters. Frank Baker, an Enid city commissioner, called the decision 'thrilling,' emphasizing the importance of protecting the city's water sources. The investigation also identified two other wells in Enid violating the state's distance rule, both of which remain active. Across Oklahoma, at least 114 injection wells are located within a half-mile of public water supply wells, serving over 300,000 people.

Enid has also requested stronger regulations on wastewater disposal near its water supply, including a larger buffer zone. The case will continue to be heard in the Oklahoma Corporation Commission's administrative law court later this year.