AP Photo/Brennan Linsley
A worker replaces dirt displaced by recent flooding at a natural gas extraction well site run by Encana Oil and Gas, in Erie, Colo., Wednesday, Sept. 25, 2013.
DENVER — Another oil spill due to flooding has been found in northern Colorado, bringing the total amount of oil released in and near the South Platte River to about 43,000 gallons, state regulators said Wednesday.
The latest spill, totaling 1,176 gallons, was found at a PDC Energy Inc. site about a half mile east of Greeley. It's the 15th found by inspectors since they started checking drilling operations two weeks ago.
The cumulative amount of spills detected so far is about the amount held by 3 1/2 storage tanks.
About 20 percent of the flooded wells in the Wattenberg Field have not yet been inspected, so more spills could still be found.
Officials at the Colorado Oil and Gas Conservation Commission originally expected the work to take up to 90 days, given the difficulty accessing sites because of damaged roads and flooding, spokesman Todd Hartman said.
The commission also said about 18,060 gallons of wastewater containing residual amounts of oil and gas was spilled in the flooding. So-called produced water is stored in tanks at wells for disposal or recycling.
Meanwhile, people are being warned to stay away from flood-damaged oil and gas production equipment.
Commission officials said the equipment and tanks in the area could pose a risk because they may still be pressurized and contain flammable liquids. The equipment may be unstable and shift, fall or roll.
People who see tanks or other equipment that has moved from an oil or gas location are asked to contact the commission to report the location of equipment and tanks that are not being repaired or replaced by the operators.
In a statement, the commission said 55-gallon drums are generally not related to oil and gas operations. Tanks used for oil and gas operations typically hold between 200 and 400 barrels, or about 8,500 to 17,000 gallons. Stray 55-gallon drums should be reported to local law enforcement or public health officials.
About 1,900 wells were shut down at the height of the flooding. Officials at Noble Energy Inc., the largest oil producer in Colorado, told The Denver Post that it suffered between $7 million and $17 million in losses because of flood damage and lost production.
Three of Noble's tank batteries released 8,900 gallons of oil.
The South Platte is major source of drinking water and agricultural water. The millions of gallons of sewage dumped into the river from broken sewer pipes and waste treatment plants poses a bigger problem than the oil spilled, The state health department has said.
In addition, the large volume of water that rushed out onto the plains from the foothills apparently swept away visible evidence of the oil.
Researchers from the University of Colorado studying how to limit the natural gas industry's impact on the environment and communities are collecting soil samples along the river looking for evidence of benzene, a carcinogen, and benzene compounds, left behind by the spilled oil.
MORE: Colorado Floods Leave Devastation
An M-923 U.S. military logistical transportation vehicle lies on its side in a ditch in Longmont after being washed away by floodwaters as local residents were cleaning up in the wake of heavy flooding on Sept. 16, 2013, in Longmont, Colo. (Marc Piscotty/Getty Images)