Summary

  • The Oklahoma Corporation Commission’s 2018 approval of the Flying Monkey disposal well, granted without the hearing Oklahoma Administrative Code requires when an injection well is to be sited within a half-mile of a public water supply, set in motion an eight-year arc of structural-integrity failures and unrevoked operation that ended only after investigative reporting and a July 2026 tubing leak converged on the well’s operator.
  • Hinkle Oil & Gas’s 2018 permit application, in which a box was checked stating the injection well was not within a half-mile of a public water supply well, was characterized by Enid’s 2025 complaint as “demonstrably false”; Hinkle has declined to answer questions from the newsrooms, and the available reporting does not record any accountability action against the original operator.
  • BCE-Mach III Midstream Holdings, which acquired the Flying Monkey in 2020, framed the well’s permanent Sept. 14 closure as a response to the well’s being “underutilized and operationally unnecessary”; the closure followed a 90-day state fix-or-plug order triggered by a July tubing leak that was reported nine days after the Frontier/ProPublica investigation published.
  • The Corporation Commission has not, in available reporting, committed to a review of the at-least-113 other injection wells statewide within a half-mile of public water supply wells, nor to a reassessment of the 2018-vintage permit pathway that produced the Flying Monkey approval; the Commission’s administrative-law court is scheduled to hear Enid’s permit-revocation and regulatory-broadening case later this year.

BCE-Mach III Midstream Holdings LLC permanently plugged the Flying Monkey disposal well near Enid, Oklahoma on Sept. 14, with a state representative on site to witness a cast iron plug followed by more than 200 sacks of cement, according to a report the company filed with the Oklahoma Corporation Commission. The Frontier and ProPublica investigation that prompted the closure found the Corporation Commission had approved the well in 2018 in violation of a state rule that requires a hearing when injection wells are sited within a half-mile of public water supply wells; the well sat approximately a quarter-mile from two of Enid’s municipal groundwater supply sites. Across Oklahoma, the newsrooms identified at least 114 injection wells sited within a half-mile of a public water supply well, with more than 300,000 Oklahomans relying on those water sources; the closure of the Flying Monkey reduces that count by one, with at least 113 wells remaining in operation.

The 2018 approval and the rule that should have required a hearing

Oklahoma Administrative Code prohibits wastewater injection within a half-mile of a public water well unless the Corporation Commission holds a hearing to evaluate the activity’s effect on groundwater. The rule creates a category of higher-scrutiny permits for proximity-elevated sites. The Frontier and ProPublica investigation found the Corporation Commission did not hold such a hearing before approving the Flying Monkey in 2018.

The original operator, Hinkle Oil & Gas, submitted the permit application in which a box was checked stating that the injection well was not within a half-mile of a public water supply well, according to the 2025 complaint filed by the city of Enid. The city’s lawyers characterized that statement as “demonstrably false.” The well sat approximately a quarter-mile from two of Enid’s municipal groundwater supply sites. Hinkle previously declined to answer questions from the newsrooms about the Flying Monkey.

The pathway from the 2018 application to the disposal revenue the well generated across its operating life runs through an approval stage at which the proximity question was not contested and a hearing was not convened. BCE-Mach III Midstream Holdings later refiled a permit application for the Flying Monkey in which it acknowledged the proximity of the city’s water supply wells, the newsrooms noted — an acknowledgment that contrasts with the 2018 application’s denial of proximity.

A spokesperson for the Corporation Commission did not respond to requests for comment on the closure, including about the agency’s role in the well’s shutdown. The Commission previously declined to comment on the city’s 2025 complaint because the matter is an active case.

Eight years of integrity-test failures, none of which closed the well

The Flying Monkey had a troubled operational history. State regulators shut the well down repeatedly in the last five years after it failed tests of its structural integrity. These failures can indicate a problem that might allow wastewater to escape, potentially threatening drinking water sources. The well failed five of these tests since 2021. In each case, the well was returned to operation; in no case did the cumulative record produce a permit-revocation proceeding until Enid filed its 2025 complaint, which the newsrooms identified as the first reported escalation to permit-revocation proceedings.

In early July 2026, nine days after the Frontier/ProPublica investigation published, the Flying Monkey’s owner reported another leak in the well’s tubing. The state gave BCE-Mach III Midstream Holdings 90 days to fix the leak or to permanently plug the well. The company chose to plug. The available reporting does not address whether the 90-day order was issued on the merits of the July leak alone, or whether the cumulative integrity-failure record, the newsrooms’ investigation, and the leak together informed the Commission’s posture. Whether the agency would have compelled closure absent the company’s voluntary decision is not addressed in the newsrooms’ reporting.

Who benefits: Hinkle, BCE-Mach III, and the city of Enid

The benefit pathway identified in the newsrooms’ reporting splits across the three principal parties.

For Hinkle Oil & Gas, the original operator, the 2018 permit application attested a fact — that the well was not within a half-mile of a public water supply — that the city’s lawyers have characterized as “demonstrably false.” Hinkle previously declined to answer questions about the Flying Monkey. The available reporting does not record any agency enforcement action against Hinkle for the allegedly false attestation, nor any legal action against the original operator in connection with the 2018 application. Hinkle’s lack of a reported accountability outcome stands in contrast to BCE-Mach III’s voluntary closure and to the city’s active complaint posture.

For BCE-Mach III Midstream Holdings, the benefit pathway ran in the opposite direction by the time of the closure. Eric Huddleston, an attorney representing BCE-Mach III, said the company decided to permanently shut the well after determining it was “underutilized and operationally unnecessary.” The article does not document the well’s throughput or revenue history that would substantiate the company’s characterization. The closure removed a liability asset: a well that, by the company’s own framing, no longer contributed meaningfully to the business but had become a focal point of public and regulatory attention after the July leak and the publication of the investigation.

For the city of Enid, the closure returned a resource that had been at risk to municipal control. Frank Baker, an Enid city commissioner, told reporters the decision was, “for lack of a better word, thrilling because this is such a vital issue,” and added that “our water sources have been put in danger.” He expressed hope that the closure would be replicated statewide: “I hope and pray this is an example that we’ll start to see replicated across the state in the near future.” The city did not learn of the well’s closure until a reporter informed officials, a sequence that itself records the asymmetry between the company’s filing and the city’s awareness. The closure does not address Enid’s pending requests for stronger distance buffers and broader regulations on oilfield wastewater disposal near its water supply, both of which remain pending in the Commission’s administrative-law court. The request for stronger regulations comes amid a “recent uptick in wastewater injection in the Enid area,” according to a legal filing made by the city, as the newsrooms reported.

The newsrooms’ reporting does not include statements from the operators of the two other Enid wells, from the broader set of operators holding permits within the 114-well statewide list, or from the agency personnel who reviewed the 2018 application. The benefit pathways for those operators, and whether they too have multi-failure integrity histories, are untraced in the available reporting.

The 113 remaining wells and the regulatory pathway

The closure resolves one well’s risk. The arithmetic of the next several years under the regulatory structure described in the article is: at least 114 wells minus 1 equals at least 113. The at-least-113 figure declines only via continued voluntary pluggings, further enforcement actions in the Corporation Commission’s administrative-law court, or a revised half-mile buffer such as the city of Enid has requested.

The newsrooms’ investigation identified two other wells in Enid that violated the state distance rule between wastewater injection wells and the city’s groundwater supply sites. Both wells, which are owned by other companies, remain active. The available reporting does not name those owners, nor does it trace their permit histories or integrity-test records. The 114-well statewide count includes those two Enid wells as well as at least 111 other sites across Oklahoma, in communities that collectively include more than 300,000 residents.

The Corporation Commission has not, in available reporting, committed to a review of the at-least-113 other at-risk permits, nor to a reassessment of the procedural pathway by which the 2018 Flying Monkey approval was granted. Whether the absence of a hearing in the Flying Monkey case is anomalous or representative of the Commission’s permitting practice is not addressed in the available reporting. Whether the half-mile buffer in the state rule reflects current hydrogeological evidence, or whether the rule has been revised since 2018, is also not addressed.

The pending administrative-law court case will be heard later this year. The case will consider Enid’s 2025 complaint seeking revocation of the Flying Monkey’s permit — a request rendered partially moot by the Sept. 14 closure, though the broader regulatory requests for stronger distance buffers and stronger regulations on oilfield wastewater disposal near the city’s water supply remain in play. The case will continue to be heard in the agency’s administrative-law court.

Open questions the article does not resolve

Several specific factual gaps remain in the available reporting. The newsrooms’ reporting characterizes the hearing requirement as a “state rule” and the body paragraphs identify it as “Oklahoma Administrative Code” by reference to standard Oklahoma oil-and-gas regulatory architecture; the available reporting itself does not name a specific code title or section. Whether the rule has any statutory component is not addressed in the article.

Extrapolating from a single well’s arc to a multi-year timeline for the remaining at-risk permits requires the assumption that the regulatory and operational patterns observed in the Flying Monkey record will hold across the other cases. Whether the other at-least-113 at-risk wells show similar time-to-resolution arcs is not addressed in the available reporting.

The 2018 Hinkle application attestation, characterized by Enid’s lawyers as “demonstrably false,” has no reported accountability outcome. The article records Hinkle’s declination to answer questions but does not report any agency or legal action against the original operator.

BCE-Mach III’s stated reason for closure, “underutilized and operationally unnecessary,” is the company’s own characterization; the article does not document the well’s throughput or revenue history that would substantiate the claim.

The article does not address whether the absence of a hearing on the 2018 application is anomalous or representative of the Commission’s permitting practice. The two other Enid wells identified as violating the same distance rule are owned by unnamed companies; whether their permit histories follow the same pattern as the Flying Monkey is untraced.

The article does not address why enforcement of structural-integrity failures escalated only after journalistic publication. The well failed five such tests since 2021; the 90-day fix-or-plug order followed a July leak report, which came nine days after the investigation. Whether the order was issued on the merits of the leak alone, or whether the Commission would have compelled closure absent the company’s voluntary decision, is also not addressed.

Additional considerations

Across the state, more than 300,000 Oklahomans live in communities that rely on the water wells that sit within a half-mile of the at-least-113 injection wells. The Commission’s 2018 approval of the Flying Monkey, granted without the hearing the state rule requires, is the documented instance. The available reporting does not establish whether the same procedural pathway recurred in the 113 other approvals.

The 2018-vintage application, the multi-year integrity-failure arc, the 2025 city complaint, and the 2026 closure are recorded; the Commission’s posture toward the remaining cases, the status of the rule itself, and the question of whether the structural pattern in the Flying Monkey record is replicated elsewhere are open. The closure returns one well’s specific risk to municipal control. The pathway that produced the approval, the cumulative record of integrity failures, and the timing of the agency’s response are the documented record from which the broader question — whether the regulatory review process for the remaining at-risk wells will follow the same arc — is to be assessed.

Analytical techniques used in this piece

This analysis applies the methods below. Each links to a short, plain-English explainer you can read and reuse.

Cui Bono — Who Benefits
Asks who gains and who pays from a state of affairs, decision, or claim.
Red-Team Assessment
Models a capable adversary probing a plan for the seams they would exploit.
Systems Dynamics (Structural)
Maps a system’s structure — stocks, flows, and the architecture that shapes its behavior.
Tragedy of the Commons
A shared resource is depleted because each user’s incentive is to take more.