Oil and gas companies fail to disclose toxic chemicals at Colorado well sites
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In 2022, Colorado passed a law requiring oil and gas operators to let the public know what chemicals were being used underground. Chemicals are routinely used for drilling and fracking and many are considered hazardous to human health.
But a new report showed as of May 1, 2025, 65 percent of operators have not disclosed the chemicals they use.
Dusty Horwitt, consultant for the group Physicians for Social Responsibility, said people living near oil and gas wells disproportionately experience negative health effects.
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"It's really critical for people living near oil and gas operations, for their health providers, for first responders to know what chemicals are going into the wells," Horwitt contended.
Chevron and its subsidiaries operate more than half of the 439 wells with no chemical disclosures posted on FracFocus, the official state-designated repository. The company has come under increased scrutiny after an explosion in Weld County released a watery mix of chemicals and crude oil into surrounding properties and waterways for five days straight last month. Chevron has not yet responded to a request for comment.
Many oil and gas companies have pushed back against revealing their chemicals, arguing the information was a proprietary trade secret. Horwitt pointed out the 2022 law requires operators to disclose the names of chemicals, but not the formula.
"Similar to the way that food makers have to publish the list of the ingredients in a food product, but not the recipe," Horwitt explained.
Colorado has also banned the use of PFAS but Horwitt noted the new report raises serious concerns about whether forever chemicals continue to be used. He argued ultimately, Governor Jared Polis and his appointees on the Energy and Carbon Management Commission are responsible for upholding the law.
"Is it that the companies who operate the wells aren't complying, is it that the companies that manufacture the chemicals aren't complying?" Horwitt asked. "Whatever the case may be, the governor and the state agency -- the ECMC -- need to get to the bottom of this."
