COLUMBIA — It’ll take $77 million to bring Columbia’s wastewater treatment plant and sewer collection system up to speed, city officials said, and they plan to ask voters to approve a bond issue for that amount on April 8.
Approval of the measure would mean a series of annual increases in sewer utility bills. Steve Hunt, manager of environmental services for the sewer utility, told the City Council during a Monday work session that projections show average residential sewer bills rising incrementally from $12.25 this fiscal year to $22.19 in fiscal 2014.
The council heard presentations from Hunt and from consultants Larry Chapple and Derek Cambridge of Black and Veatch. They said the bulk of the proceeds from the bond issue would go toward improvements at the wastewater treatment facility.
The money first would allow the city to add two new nitrifying trains and a blower building to the treatment plant and to meet the Missouri Department of Natural Resources requirement for increased capacity. Currently, the plant, along with wetlands wastewater treatment cells, allows the city to process 20.6 million gallons of sewage per day.
The nitrifying trains, which remove ammonia from sewage, will enable the city to meet a new DNR limit of six milligrams of ammonia per liter so that it can continue directing treated wastewater into its wetlands and the Eagle Bluffs Conservation Area. Although the plant and wetlands provide an acceptable level of disinfection, they do not remove ammonia. And there’s a chance the DNR could make its ammonia limits even more stringent, Cambridge said.
“I don’t have a high level of confidence (the limit) won’t go lower,” he said.
While meeting the new requirements for pumping effluent into Eagle Bluffs will be costly, council members agreed it’s a top priority.
“It’s the right thing to do,” Fourth Ward Councilman Jerry Wade said.
Proceeds of the bond issue would also pay for general improvements to the 30-year-old treatment plant, including the replacement of an engine generator.
That project, along with the nitrifying trains and the blower building, would cost a combined $49.1 million, the consultants said. Another $17.9 million would be necessary to improve the city’s treatment of biosolids, to control odor at the plant and to boost the plant’s ability to remove grit from wastewater.
Although better grit removal isn’t necessary to meet DNR’s new requirements, it would be cost-effective, the consultants said, because grit causes a lot of wear on plant equipment.
“This (project) would be an investment to preserve your other equipment,” Chapple said.
The remaining $10 million of the bond issue would be slated for improvements in the sewer collection system, including annexation of some private sewer lines, repairs to sewer mains and manholes and extension of sewer lines. About $3 million could go to pay for extending sewer service to Columbia’s new high school site on St. Charles Road.
The consultants said that if the bond issue is approved, the city probably wouldn’t need another until 2025. That, however, is based on their prediction of future DNR and Environmental Protection Agency requirements.
Third Ward Councilman Karl Skala supports the proposal, but remained skeptical that requirements won’t change.
“There’s a ton of assumption,” he said.
City Manager Bill Watkins said he expects to hold a public hearing on the proposal in January and to place it on the ballot for the April 8 municipal election. That ballot will also include City Council and school board races, as well as similar races in smaller towns throughout the county.