MASON CITY — The City Council in Mason City this week approved a facility plan for a $26 million update to the city’s Water Reclamation Facility improvements project to deal with reducing nutrients being put into the Winnebago River.
The city is required by the Iowa Department of Natural Resources to complete improvements to the facility by October 2027. WHKS has worked with the city over the past several years to develop a plan to meet those requirements.
Bill Angerman of WHKS says Mason City is not the only community having to deal with this mandate to help reduce nutrients causing the dead zone in the Gulf of Mexico. “A large portion of the country is impacted by this, so basically it’s the Missouri River, Ohio River, Mississippi River basins. Each state individually then is able to come up with their own strategy. Iowa’s strategy is that all major facilities in the state have been imposed with these phosphorus and nitrogen limits.”
Angerman says there have been some improvements needed to be done at the facility, but they’ve been postponed knowing this project would be started in the near future. “We had $4 million worth of improvements that were basically delayed. We said those were things that we might have done over the last five or ten years, but we’re going to delay these and try to time them all at once so we are maximizing items. Another big item is the electrical and controls. Again, Bill Stangler and his staff and we have been delaying improvements. About $7 million of these improvements are really things that we’ve been delaying, again trying to strategize and optimize.”
The council had five options of plant upgrades to choose from and has selected converting to a biological method compared to using chemicals. Angerman says in the long run the biological method is more cost-effective. “What we look at was from a construction perspective, what can we do as far as tanks, treatment process, biological versus chemical removal. What we did was a life-cycle analysis, taking into account construction plus operations and maintenance, what’s the lowest life-cycle cost, it was converting to this biological nutrient removal, which is basically called activated sludge. Think of it that as a big tank and we’re going to blow air into it.”
Besides choosing the method of upgrading the plant, the council approved a professional services agreement with WHKS for final design engineering services associated with the project.