Five years ago, Oklahoma oil regulators took on a project with an impressive name: the Source of Truth. State officials wanted a comprehensive database capturing all vital information about the more than 11,000 wells in Oklahoma that shoot the toxic byproduct of oil production back underground.Id heard about this project from several people during the 18 months I had spent reporting on the growing number of cases where oilfield wastewater blasted out of old wells, known as purges, after being injected underground at high pressures. State employees also referenced the project in internal communications that I received after filing nearly a dozen public records requests to the Oklahoma Corporation Commission, which regulates the oil and gas industry.Just before the new year, the Source of Truth itself landed in my inbox in response to an unrelated records request. And it was explosive, revealing a pattern of rule violations by oil and gas companies that state regulators allowed to continue.The project was supposed to clean up or fix state data regarding how much wastewater was being injected and the pressures at which it was being pushed underground. The agencys databases, many of which were based on decades-old paper records, were riddled with contradictory or missing information. In many cases, the agency failed to update its records. More than 1,300 errors were identified.But the Source of Truth found more than just messy data. It also allowed regulators to pinpoint nearly 600 wells that were operating illegally: injecting wastewater above their permitted pressures or volumes.Excessively high injection pressures and volumes can lead to purges and groundwater pollution.That wasnt all. The report also showed that regulators had allowed more than 1,400 other older injection wells to operate for decades without any limits whatsoever on injection pressures or volumes grandfathered in from an earlier era of permissive oversight.In the course of my reporting on oil and gas pollution in Oklahoma, Ive uncovered systemic underregulation by the state as well as a few crucial fork-in-the-road moments, instances when state regulators could have taken action to bring the industry into compliance with their own rules.The completion of the Source of Truth was one of them.With this report, the agency had in hand an extensive list of potentially problematic wells that were either injecting above legal limits or lacked limits entirely. These wells accounted for nearly a fifth of the active injection wells in the state. They warranted scrutiny, my agency sources told me.But after the report was completed, in 2021, regulators did not act on its findings. They did not make oil and gas operators comply with the injection limits on their permits or establish limits on older wells to bring them up to modern standards, agency employees said. They never made the report accessible to the wider agency staff, according to my agency sources and internal documents.In the meantime, the number of oilfield purges grew steadily, from about a dozen in 2020 to more than 150 over the next five years, according to a Frontier and ProPublica analysis of pollution complaints submitted to the agency.As agency employees investigated these pollution events, they identified plenty of problematic wells that, unbeknownst to many of them, had already been flagged in the Source of Truth.The Oklahoma Corporation Commission looked into using the Source of Truth database in the past and elected not to use this form of data collection, said Jack Money, an agency spokesperson, without saying why.Money did not say why regulators did not force oil companies to comply with the limits they had agreed to, why the agency chose not to establish limits on the older wells or why it did not share the Source of Truth widely. He did not respond to follow-up questions.Injecting Without LimitsThe core problem identified by the Source of Truth dates back to 1981, when Oklahoma applied to take over regulation of oil and gas injection operations from the U.S. Environmental Protection Agency.Purges often occur at abandoned, unplugged oil wells as a result of high-pressure injection. Obtained by ProPublica and The FrontierBefore the feds would agree to hand over control, the state had to prove that its regulations would protect groundwater as required by the federal Safe Drinking Water Act. The 1974 law created basic standards for regulating underground injection.This meant big changes in Oklahoma. For decades, the state had routinely approved parcels of land for drilling, along with groups of injection wells that help produce oil. This type of injection well takes wastewater after it has been separated from oil and shoots it back underground to push more petroleum to the surface a technique known as waterflooding.The state proposed approving every injection well individually, setting a maximum pressure and volume for each one to prevent contamination of freshwater, according to Oklahomas application to the EPA. Setting such limits would help ensure that the injected wastewater would not fracture the rock surrounding the well and pollute groundwater.Oklahoma won the EPAs approval, becoming one of the first states to gain direct control of underground oil and gas injection. Today, more than 30 states have authority over regulation of underground injection for oil and gas.Oklahoma did not retroactively apply its new standards. And the EPA never forced it to. Thousands of existing wells were allowed to continue injecting with no volume or pressure limits.Federal regulators hands appear to be tied by the language of the Safe Drinking Water Act, which allows injection without limits to continue for the life of the well, according to Joseph Robledo, a spokesperson for the EPA regional office that oversees Oklahoma.EPA acknowledges that because oil and gas activity began in Oklahoma long before the establishment of federal [underground injection] regulations, many wells in Oklahoma do not meet modern standards, Robledo wrote in an email.He said Oklahoma has taken steps to modernize its oil and gas inventory and submits regular reports to the EPA.But my reporting shows that state regulators have not directly addressed the issue of wells without injection limits.I consulted more than a half dozen experts in oil and gas injection, including lawyers, about these wells operating under outdated standards. None had any idea that so many of Oklahomas injection wells had been grandfathered in and were not abiding by volume and pressure limits. Several noted, though, that the federal law is unclear on what state regulators were allowed or required to do; the Safe Drinking Water Act prohibited states from interfering with oil and gas operations that existed prior to the laws passage unless the operations endangered drinking water.Because the state never investigated these wells, no one can say for certain whether they do, in fact, threaten drinking water. But my reporting shows that excessively high injection pressures and volumes have caused mass pollution in Oklahoma.The most recent state data indicates that 88% of the 1,400 wells found by the Source of Truth to have no pressure or volume limits are listed as active, injecting over a hundred million gallons of wastewater beneath the ground last year.Establishing pressure and volume limits for each of these wells wouldve been a huge task, requiring regulators to approve new permits for each one.Nevertheless, experts say that responsible regulation of underground injection requires, at a basic level, knowing how much and with how much force water is being pushed underground.Pressure and volume limits are key to ensure that injection wells arent, first and foremost, endangering groundwater, but also to prevent bad outcomes like earthquakes and purges, Adam Peltz, an attorney who directs the energy office for the Environmental Defense Fund, an advocacy nonprofit, told me.Problematic Wells Near PurgesIn the years since the Source of Truth was completed, purges multiplied across the state, with toxic wastewater gushing to the surface, polluting farmland and water sources.One especially bad series of purges occurred in a rural stretch of Carter County in south central Oklahoma. Huge volumes of wastewater poured from the ground for months at a time starting in 2021.In an August 2022 internal email chain discussing the response to the ongoing wastewater eruptions, one environmental supervisor pointed out that the Source of Truth could have been a tremendous help to his team as they evaluated the injection wells near the purges but they did not have access to it.After I got the Source of Truth documents, I checked to see if wells that it flagged as problematic were later identified by the agency to be located near purges in recent years. There were at least 30 matches. If the agency had proactively investigated the problem wells to see if wastewater was spreading widely belowground, it may have been able to identify several oilfields where overpressurized injection would later cause purges.In theory, the EPA could still force Oklahoma to improve its regulation of oil and gas injection, if federal officials found that its wells were systematically threatening groundwater. There is some precedent for this, but its rare.In California, federal officials helped conduct an audit of the states oilfield wastewater injection policies in 2011 and found that it had failed to properly protect aquifers. State and federal officials subsequently created a plan to overhaul Californias underground injection regulations. No state has ever had its oversight of oil and gas injection revoked.Similar scrutiny is unlikely in Oklahoma under President Donald Trump, whose EPA is radically loosening regulations on industry.Robledo, the EPA spokesperson, noted in an email that there are some circumstances that would require Oklahoma to place limits on these old wells, including when they are contaminating drinking water or violating other state rules.But state regulators would not know if these wells are contaminating drinking water if they do not investigate them.I asked state regulators whether they would address the many wells still injecting under outdated regulations, a situation created four decades ago and highlighted by the Source of Truth.They did not answer.Help Us Report on the Impact of Oil Field Waste in OklahomaToxic wastewater from oil fields keeps pouring out of the ground in Oklahoma. For years, residents have filed complaints and struggled to find solutions. We need your help to understand the full scale of the problem.Share Your ExperienceThe post Oil Regulators Found Hundreds of Wells Violating Oklahoma Rules. Then They Ignored Their Findings. appeared first on ProPublica.