Washington city staff want to start a conversation of how sludge will be processed in the coming years — including the proposal for new equipment.
The city’s board of public works Tuesday, Aug. 13, discussed plans for sludge removal generated from wastewater operations.
“We are always going to be generating between 300 and 350 dry tons of biosolids, which is our sludge, a year, while the plant is running,” Public Works Superintendent Kevin Quaethem said. “We generate that much because our plant has a really effective removal rate of biosolids.”
The city is running out of places to dispose of the sludge, he commented. It goes to landfills, the airport and farm fills in the area.
Quaethem is proposing that the city purchase a BIO-SCRU biosolids drying system to combat the problem.
As the sludge dries, it generates a dust that can be explosive, Quaethem explained. The new, proposed system would contain the dust and remove it.
“This system would create a granular product, that would look like fertilizer you could buy at the store,” Quaethem said.
In fact, Class A sludge can be used as a fertilizer for gardens, farms and yards. The new system would create Class A sludge.
“It’s opening the door to a lot of options we could do, but it’s also reducing the amount of sludge, or biosolids we would have,” Quaethem said.
Quaethem added that the cost would be $3 million total. He proposed that in the budget. The equipment itself costs $2.4 million, but the additional cost would be for installation.
Board member Brad Mitchell asked what is wrong with the current system, and is the cost of the new system going to be worth it.
Quaethem said that it would save money in the future. However, he doesn’t expect the drying system to be approved. He wanted start the conversation because disposing of sludge will be a major issue if the city doesn’t act soon.
“The point is, that in a few years we are going to have to start looking at something,” Quaethem said. “I don’t want to be here toward the end of the time and we didn’t do something.”
The current cannibal system for cleaning the sludge doesn’t work, he further added.
The company who created it, Siemens Wastewater Industry, is no longer in business and has multiple lawsuits brought about by other towns that used the process, Quaethem said.
“It hasn’t worked, and it doesn’t work,” Quaethem said. “Almost every community that put it in, that was led to believe it would work, well it doesn’t work.”
Quaethem explained that the cannibal system worked on a theory that was not feasible, but the drying system would slow the growing sludge problem.
“This is just one solution to getting rid of the sludge,” added Public Works Director John Nilges. “We need to look at other options that may be more cost-effective as well.”
The next board meeting is scheduled for Tuesday, Sept. 10, at 7:30 a.m. at Washington City Hall.