City outlines how much residents, business owners will pay for the new wastewater treatment system. 4:13 pm, Feb. 3, 2021 × ORONOCO — The town is ready to drop its unflattering epithet. With the money (mostly) in place, and plans being drawn up, Oronoco is ready to hand off the title of "Minnesota's largest unsewered city" to some other town. "I think it’s definitely going to be plus for us, for our citizen and for our growth, residential and commercial growth," said Oronoco Mayor Ryland Eichhorst. With aging septic systems dotting the town that sits on karst geology – which allows water from the surface to seep down into the groundwater fairly quickly – along a running river, a wastewater treatment plant can't come soon enough, Eichhorst said.