Eau Claire’s sewage treatment plant is doing such a good job of removing solid waste from water flushed out of homes and businesses that it needs more room to store the stuff.
The city plans to spend $1.2 million next year to build more storage space for sludge at the wastewater treatment plant on Eau Claire’s southwest side.
At a recent budget work session, community services director Jeff Pippenger explained the plant is pulling more solids out of wastewater than initially expected.
“Our efficiency is 99 percent,” he said.
Water pumped out of the plant is cleaner than the water it joins in the Chippewa River, Pippenger noted.
The plant got straight As on an annual report card — except for a B grade for sludge storage.
In that category, it violates a state Department of Natural Resources permit that governs how much room is needed to store solid waste.
The plant produced 9 million gallons of sludge last year. The DNR requires plants have capacity to store solids for six months. In Eau Claire’s case that would be tanks capable of handling 4½ million gallons, but the city plant only has enough room for 4 million.
Expanding the plant’s storage capacity is listed as a high priority in the city’s proposed 2019-2023 capital improvement plan.
The plant underwent a major overhaul in 2013 to 2015, which cost about $39 million to incorporate new technology, change how the facility processes waste and improve filtration.
Those improvements also included better methods for capturing methane gas from solids at the plant, which is then used to fuel biogas boilers at the facility.
“We don’t use any gas from Xcel anymore,” Pippenger said.
He added after the plant became more self-sufficient, Xcel Energy even called to make sure its utility meters were still working right because they showed no outside gas had been used.