The district’s copper ion generation system cleared out the mussels, according to a news release from the BCMUD.
Zebra mussels are an invasive species that can clog water intake systems, contaminate water and disrupt ecosystems, resulting in foul-smelling water, according to the news release.
Copper ion generation systems introduce low levels of copper solution in water intakes, and the increased copper concentration in the water, though minimal, hinders zebra mussel development.
How we got here
The news comes after years of unsuccessful efforts to eradicate the invasive species. The release said zebra mussels were first found in Lake Texoma in 2009 and have since infested 33 Texas lakes. Lake Georgetown and Stillhouse Hollow Lake, BCMUD’s two largest water sources, were among those infested.
Zebra mussels overwhelmed an intake in Lake Austin in February 2019, and foul-smelling water seeped into thousands of home water taps in Central and South Austin as a result, the release said.
“Zebra mussels were first noticed at Lake Georgetown in 2017,” BCMUD Facilities Manager Bill Carr said. “Around 2018 we started feeding sodium permanganate at the [BCMUD] Water Treatment Facility. The hope was to keep the mussels out of our raw water pond and all of the piping infrastructure at our facility.”
Carr and his team tried other chemical-based methods after sodium permanganate proved ineffective, but none were as effective as the copper ion system, according to the release.
Dig Deeper
Carr said the amount of copper that ends up in the water supply is minimal. The BCMUD is able to render zebra mussels harmless with a dose of under 10 parts per billion, he said, noting the Environmental Protection Agency sets the maximum contaminant level of copper in drinking water at 1,300 ppb.
What else?
The copper ion system costs $783,000, Carr said, but the savings from the system have offset the initial cost multiple times over.
