The EPA has a plan to channel Willow Creek on bedrock which will remove the threat of the rock pile washing downstream at the Nelson Tunnel/Commodore Waste Rock superfund site. Here’s a report from Matt Hildner writing for The Pueblo Chieftain. From the article:
Hays Griswold, who’s overseeing the stabilization of the pile for the EPA, said the original plan to build a ramp up the channel for West Willow Creek that would serve as the stream bed was abandoned after this year’s runoff threatened to wash away part of the two-acre pile…
High runoff in 2005 did wash away large portions of the pile and sent debris streaming down the canyon where it threatened to block the flume that funnels the creek through town. That event highlighted the instability of the pile, which also contains contaminants such as arsenic, cadmium, lead, manganese and zinc, among others.
The new design for the project, once the channel is established in bedrock, would line grouted boulders four-to-six feet up the side of the bed. From there, the pile would be benched and pushed back further. “If we can make it as wide as we can, I don’t foresee anybody having to fight with it again like the county has and the city has every year,” he said. In the meantime, the EPA’s contractors are digging through various cribbing in the pile in an effort to reach the remaining third of the bedrock they believe is needed for the stream bed. Griswold estimated the stabilization of the waste rock pile would cost between $2 million to $3 million.
While the end of work is near on the rock pile, the EPA is still doing testing inside the Nelson Tunnel to determine the type and number of water sources entering the 8,000-foot adit that drains five mines before dumping into West Willow Creek. The agency did the first round of testing on the site in November and plans another round next week. After the data is gathered, the agency will do a feasibility study on the best cleanup solution for the tunnel, which is the watershed’s biggest contributor of cadmium, lead and zinc.
More Coyote Gulch coverage here.