Click the link to read the article on the KUNC website (Scott Franz). Here’s an excerpt:
May 31, 2026
A reservoir built to serve nearly a million Northern Coloradans started filling this spring. But Chimney Hollow’s future is still murky weeks after the initial fill. Chimney Hollow will eventually pull water from the Colorado River near its headwaters in Grand County to serve a dozen fast growing cities on the Front Range from Broomfield to Greeley…Chimney Hollow is holding just 2% of its total volume today because there’s a problem. Northern Water discovered that some of the rocks it used to build the massive dam at the reservoir contained radioactive uranium. It was naturally occurring, but it set the project back at least a year. Northern Water is still coming up with a mitigation plan.
“Really, the best way to kind of move that uranium out is to draw down the water and force that out,” spokesperson Rachel Stevens said. “But before we make any of those decisions, we really want to see what the levels of uranium are.”
So every week, crews are taking water samples from the small pool and sending it to a lab to see how much radioactive material is really in the water. The results are expected soon. Northern Water has only been able to test how uranium leaches out of the rocks in a laboratory setting. Filling the reservoir just slightly will help reveal the extent of the problem.
