Despite spills of nearly 62,000 gallons of petroleum products from oil and gas wells during September’s floods, no pollutants have been detected in Colorado’s waterways.
That’s according to testing done by the the Colorado Department of Public Health and Environment. They collected samples in 32 locations in the South Platte basin.
But where did the petroleum products that spilled into the floodwaters go?
Steve Gunderson is the Director of the Water Quality Control Division for the state.
"...at least the lighter hydrocarbons...would end up vaporizing into the air relatively quickly."
“The fact of the matter is an over 40,000 gallon release of petroleum products to surface water is a very significant amount of release, but you have to put it into perspective," Gunderson said. "It happened at a time when the flows were a couple hundred times greater than what is normal, a tremendous volume of water."
“Some of the hydrocarbon could be diluted by just the tremendous volume of water, some of it, the water was moving very rapidly so much of it moved downstream. And then the other factor is that at least the lighter hydrocarbons with that much movement of water churning it around, those hydrocarbons would end up vaporizing into the air relatively quickly,” Gunderson said.
He adds they weren’t just looking for oil and gas pollutants.
"Needless to say a spill like that is very alarming but it occurred at a time when the volume of water was just totally overwhelming. So we did not detect any volatile organic compounds. We certainly found high levels of E. coli. The volume of raw sewage that was lost during the flood really was far greater than the volume of hydrocarbons that were spilled,” Gunderson said.
The highest E. coli rates were found in the Boulder Creek and Big Thompson River watersheds. Gunderson says municipal water lines are safe, but that people with wells in affected areas should get them tested.
Boulder and Weld counties are offering free well tests for residents.
Five public drinking water systems remain on boil or bottled water advisories: Jamestown, Lyons, Mountain Meadow Water Supply, Lower Narrows Campground and Sylvan Dale Ranch.
The state is also testing for metals that could have been released from mining areas, as well as the effects of the flooding on aquatic life.
