With cranes and bulldozers busy behind them, county officials broke ground Monday for a two-year, $30 million upgrade project of Butte’s wastewater treatment plant.
The upgrades to the Metro Sewer plant on Centennial Avenue should dramatically reduce nitrates released into Silver Bow Creek, boosting oxygen levels and hopefully aquatic life in the headwaters of the Clark Fork and Columbia River systems.
“This is a guarantee that people will enjoy Silver Bow Creek for generations,” Chief Executive Matt Vincent told commissioners, state and county officials and contractors before several of them shoveled dirt.
It followed a similar ceremony Friday for a new, $30 million water treatment plant at Basin Creek that will be tucked in a rural area about five miles south of the Butte airport.
In terms of costs, they are believed to be the two biggest public works projects here in the past century – both happening at the same time.
The sewer upgrades were mandated so lower amounts of nutrients are released into Silver Bow Creek, thereby reducing algae blooms that rob water of oxygen and damage the ecosystem.
As it stands now, about five miles of the creek from the plant’s discharge point are either a “dead zone” or a “high-stress zone” for fish and other aquatic life.
One new structure at the plant will be used to keep the flow of wastewater balanced as it enters bioreactors that remove most nitrates. It is then fine-screened before going through a series of giant membrane filters that remove more nitrates and phosphorous.
Plant Manager Frank Shields and representatives of the Clark Fork Coalition and Trout Unlimited hailed the upgrades as big steps toward a cleaner creek and environment.
“We’re all striving for the same goal – we are going to clean up Silver Bow Creek,” Shields said.
The upgrades are being funded largely through previously approved sewer rate increases phased in over the next few years to pay back a state loan. But the state, in a deal Vincent worked out, will reimburse the county for about $4.4 million of the costs and dampen the rate hikes.
The upgrades should be complete within the next 24 months.