Two consulting firms working for a trio of Colorado oil and gas giants submitted falsified data about the environmental conditions at hundreds of locations in Weld County, regulators alleged in a public hearing Tuesday.

State oil and gas regulators are investigating reports that environmental consultants falsified results of tests on soil, groundwater and contamination at about 350 locations in Weld County between 2021 and this summer.

Oil and gas operators shared information with the Energy and Carbon Management Commission (ECMC) that highlights falsified data for 350 sites. The work, done by independent contractors, is now under investigation.

Consultants from two third-party agencies submitted false data reports to regulators on behalf of oil and gas clients for three years, the regulatory agency said.

An initial investigation revealed no immediate threat to public health, but the companies could face criminal charges.