According to Kanawha wastewater treatment staff, a lagoon at the treatment plant failed sometime recently, probably at 11am on Sunday morning, sending treated wastewater into West Otter Creek.
The discharged wastewater had already been through primary treatment. Preliminary calculations indicate nearly 7 million gallons flowed into the creek after a pipe in the secondary treatment cell collapsed.
According to the Department of Natural Resources (DNR) Mason City filed office supervisor Trent Lambert, “The bottom line is, about 6.8 million gallons of water, that would have been legally discharged over the next few weeks, was discharged in the last 24 hours because the pipe broke.”
“The wastewater had been sampled and resampled and met state permit limits. While failure of a wastewater treatment lagoon usually send untreated or partially treated wastewater downstream, it didn’t in Kanawha today.”
Lambert went on to say that, “Failure of the pipe should remind everyone to check on the berms on lagoons and basins frequently, especially when you have had so much rain.”
Two inspectors from DNR were onsite on Monday, taking samples and working with city officials.
The creek eventually flows into Boone River about 10 miles northwest of Clarion.