Denver (AP) A western Colorado rancher and an environmental group have filed a formal complaint with state regulators over the release of tens of thousands of gallons of waste liquids from gas drilling storage pits.
Some of the waste is frozen inside a waterfall.
The Colorado oil and gas conservation commission is investigating four large releases from pits operated by two companies on top of the Roan Plateau near Rifle.
The commission says waste, including mud used in oil and gas well drilling, could flow into West Parachute Creek when the ice melts.
Rancher Sid Lindauer lives on Parachute Creek and says the state didn't tell area residents about the spills.
He and the Western Colorado Congress, an environmental group, have filed a complaint with the commission.
Deb Frazier, spokeswoman for the Department Of Natural Resources, which oversees the commission, says there's no immediate threat to wildlife or people because everything is frozen and the spills were in a remote area.