Toxic water flow in Redwell Basin stopped with tons of concrete

Artesian well no longer flows

With 18,000 pounds of concrete pumped to between 7,000 and 12,000 feet below the ground, the Colorado Division of Reclamation, Mining and Safety (CDRMS) stopped the flow of a man-made artesian well in Redwell Basin last week.

The well, which flowed out of a 2.5-inch borehole likely drilled and then abandoned sometime in the late 1960s, has been spewing metal-laden,
highly acidic water into Redwell Basin and Redwell Creek for the last several decades.
Redwell Creek flows into Oh Be Joyful Creek and then enters the
Slate River.
Reports from the state and from the U.S. Environmental Protection Agency (USEPA) have found that these water bodies are impaired and exceed the instream limits for several different metals and nutrients.
According to the CDRMS, the borehole was recognized as an issue in the early 2000s, around the same time the USEPA began looking at the damage left behind from the Standard Mine. CDRMS took the first steps toward plugging the well last year when it pumped about 3,300 pounds of grout into the hole. That wasn’t enough and the effort failed, in part because the borehole was much deeper than anticipated. The agency then made a plan to try again this fall.
This time it appears the work was successful.
“Last week we were able to pressure-grout the entire length of the borehole,” said state reclamation specialist Tara Tafi. “We brought in 5.5 pallets of grout, and put 193 94-pound bags of cement down the hole using a pressurized system that allowed us to pump to the point of refusal.”
Tafi said CDRMS was “pleased with the results of the pumping,” but its success won’t truly be known until next year when water quality testing in Redwell will be resumed.
“We’re pretty confident that we were able to grout the length of the pipe and stop out-flowing water,” said Tafi. “I’m looking forward to next year to get some really good sample results from the basin.”