The state government could require Columbia to spend millions of dollars to disinfect its wastewater, but city officials want to prove to the state that the city’s effluent is clean enough.
At issue is how much bacteria is in Columbia’s treated wastewater when it reaches the Missouri River, which is designated for swimming and other whole-body recreation. Water pollution regulations that took effect in 2005 tightened standards for wastewater flowing into the river, limiting acceptable amounts of fecal coliform and E. coli bacteria.
Columbia’s wastewater does not flow directly into the Missouri River, said Steve Hunt, a sewer engineer with the Columbia Public Works Department. Columbia pipes wastewater from its treatment plant on Gillespie Bridge Road to wetland treatment cells near McBaine. From there, the effluent is released into Eagle Bluffs Conservation Area, a state-managed wetland.
The levels of bacteria from city effluent are within regulatory standards, but Hunt said the Missouri Department of Natural Resources has informally told him that when Columbia renews its wastewater discharge permit in 2010, Columbia might fall under the more stringent standards that apply to the Missouri River.
The more stringent standards would require Columbia to spend an estimated $3.5 million by 2013 and an estimated $250,000 each year thereafter for disinfection.
Rob Morrison, chief of the Department of Natural Resources’ Water Pollution Control Branch, said Columbia could apply for a disinfection waiver, but it will be up to city to prove why disinfection isn’t necessary by doing its own sampling and data analysis.
Columbia tests its water for bacteria before the water is released into Eagle Bluffs. Hunt said the water, as measured currently, would fail to meet the bacteria standards for water flowing into the Missouri River. But he and Columbia City Manager Bill Watkins believe the effluent should be tested after it flows through the state wetlands.
Watkins said he believes the water is clean enough to flow into the Missouri River after working its way through the conservation wetlands.
The Columbia City Council is expected to vote Monday on whether to allow Watkins to contract an engineering firm to help the city make its case to the Department of Natural Resources.
“What we’re trying to do is to force DNR to tell us where we have to monitor and then to construct the argument and the background that says we should be held accountable, like all other Missouri cities, where (Columbia’s treated wastewater) gets to the Missouri River,” Watkins said. “By the time the water gets into the Missouri River, it more than meets the standards.”
At the Feb. 5 City Council meeting, Public Works Director John Glascock proposed a resolution authorizing city officials to spend $13,148 to join six other municipalities and sewer districts to challenge the necessity of disinfecting effluent going into the Missouri River.
The council tabled the resolution until its meeting at 7 p.m. Monday in the Daniel Boone City Building, 701 E. Broadway.