A 27-mile stretch of the once toxic Silver Bow Creek will be open for public use in early July, bringing a 16-year, $125 million cleanup to an end.
All that now remains of the remediation work is a final 3-mile stretch through Durant Canyon, west of Butte.
Pat Cunneen, environmental science specialist for the Natural Resource Damage Program, calls the finishing of this cleanup "a big deal."
"It’s huge," Cunneen said.
DEQ's remediation work has been ongoing since the fall of 1999. Its work included cleaning the floodplain and lengthening the stream from 21.5 miles to 27 miles. Approximately 5.4 million cubic yards of contaminated soil have been removed, with most if it hauled to a designated repository at Opportunity Ponds, east of Anaconda. There, contaminated soil removed from Missoula’s Milltown Dam, another Superfund site, was buried and capped in 2008.
The floodplain contained more than 1,600 acres of contaminated soil. The contaminants included copper, lead, zinc, cadmium, mercury and arsenic.
"We rebuilt the entire stream and floodplain," said Joel Chavez, project manager with the Montana Department of Environmental Quality.
Cunneen says that Chavez deserves considerable credit for the quality of the cleanup.
"Joel is a real humble, quiet guy, but what has been done under his watch is nothing short of amazing. It’s an eye-opener. The before and after," Cunneen said.
Natural Resource Damage Program put an additional $8 million to $9 million into restoration work along this stretch of the creek, said Greg Mullen, NRDP environmental science specialist. Mullen has been in charge of the restoration work on this portion of Silver Bow Creek since the beginning, working hand-in-hand with Chavez.
"It was all seamless, a seamless relationship," Mullen said.
Restoration also included removing additional mine ore waste, called tailings, at Ramsay Flats, about 11 miles west of Butte. In places, the tailing were as much as 13 feet deep.
"There were no bugs, no wildlife. Now we have insects and hundreds of species of birds," Mullen said.
The state improved the ecosystems along the creek bank, recovered wetland areas, and worked on the streambed and bank to encourage the waterway to meander.
After workers cleaned the streambed and floodplain, they wrapped new soil with coconut fiber, which naturally degrades. The newly planted vegetation includes over a million willow trees and close to two million wetland herbs.
Another project to improve the area and make it user-friendly is the Silver Bow Creek Greenway. This $23.5 million project will enable recreationists to bike or walk 26 miles along Silver Bow Creek from Butte to Opportunity. Project Manager Dori Skrukrud said the trail, which has portions completed, can be entered at Whiskey Gulch or at Rocker. Most of the money came from the Upper Clark Fork River Basin Restoration grant. The greenway is expected to be complete in 2018.
This project has been ongoing since 1998 and, in addition to the trail, the Greenway Service District is making additional ecological investments with plantings along the path.
One sign of the creek's health is the return of fish into the once dead waterway. Trout began to appear in the creek in 2006. (See side story.)
"There were no fish here when we started," Chavez said.
Even after the $125 million cleanup, Silver Bow Creek will not be quite up to the federal and state standards for human health. The Metro Sewer Waste Water Treatment Plant, for example, was built to discharge its nitrates and other nutrients into what was then considered an industrial waterway -- Silver Bow Creek. The discharge led to a depletion of oxygen in the creek.
Butte-Silver Bow has started building a $30.7 million upgrade to the plant, so it will be up to standard for a creek that is no longer classified as industrial.
"It will be very clean water," Butte-Silver Bow Director of Public Works Dave Schultz said.
But construction on the upgrade is not expected to be complete until the end of 2016.
Another problem is that due to technology, the state missed small contamination spots when it began the cleanup 16 years ago. One such area is at a man-made pond that feeds into the creek just south of Ramsay.
Chavez says he expects to clean those areas next winter as part of the state's operation and maintenance work.
Even after the 16-year remediation work is complete this summer, workers will be back this fall to reseed additional floodplains and plant more trees.
"It will be a while before we will really be able to say how well remedy and restoration is," Mullen said. "But every year, it gets marginally better and better. It's going to be fun to sit back and watch the recovery."