Notices of alleged reporting violations were issued to seven oil and gas operators in Weld County after an 8-month investigation into falsified data on contamination and remediation at hundreds of well sites.

The Energy and Carbon Management Commission determined that the data manipulation affected soil, groundwater, and inorganic and organic contaminant data submitted on forms required for approval of remediation of spills and closure of oil and gas facilities.

Investigators identified 3,275 instances of falsified data points on 683 lab reports spanning 404 locations.

“In some cases, sample collection dates and the name of laboratory staff personnel were modified. In other cases, hydrocarbon levels were modified such that the submitted data fell below ECMC’s thresholds. In egregious cases, contaminant levels were altered by as many as three orders of magnitude,” the commission said in a July 23 news release.

The closure approvals for all 404 sites identified so far have been revoked and the operators will have to resample and remediate any contamination before new approvals are issued.

“ECMC is aware that individuals at two environmental consulting firms — Eagle Environmental Consulting, Inc. and Tasman Geosciences — allegedly altered laboratory data that they submitted to ECMC on behalf of their clients to varying degrees: Eagle Environmental Consulting, Inc. on behalf of Chevron U.S.A. Inc. and Civitas Resources Inc. and Tasman Geosciences on behalf of Occidental Petroleum Corp,” said a November 2024 news release from the commission.

The commission said it holds the operators responsible for errors or falsifications made by contractors in their reports.

The falsification accusations have been referred to criminal prosecutors for investigation, and the commission will be cooperating with law enforcement due to the extensive nature of the allegations, the body said.

Additional safeguards were implemented by the commission in December 2024 and it has procured a forensic investigation firm to find out if there is a way to electronically review past records of other operators to detect possible falsification.