Aging infrastructure, increased population and a need to achieve compliance have prompted Waterloo to consider updating the wastewater treatment plant. The facility, built in 1951 with major upgrades in 1984, can no longer meet the city’s needs. As part of a proposed implementation schedule, construction would not begin until May 2023.
Ben Heidemann of Town & Country Engineering explained how to remedy the deficiencies and how much it would cost at Thursday’s city council meeting. This was just one step in the process of moving forward with the necessary updates. He said the utilities commission has been working on a facilities plan for the structure, located at 401 Hendricks St., for the last two years. A public hearing for the updates will be held June 10.
One of the major reasons for looking into facility upgrades was phosphorous, the Town & Country employee said.
“New phosphorous limits are taking effect,” Heidemann said.
Another aspect is the city’s “wet industries” – Van Holten, AbE Manufacturing and, up until earlier this year, Briess Malting. According to Heidemann, these create excess waste in terms of volume and strength as compared to a residential user. And Van Holten and AbE Manufacturing are expected to grow.
“The other part is everything is circa 1984 and is exceeding its useful life,” he said. “The mechanical components, the electrical components is a big one, are either no longer serviceable and able to get parts for them or are very near reaching the end of their useful life. And as you can expect a plant made in 1984 can no longer meet today’s standards.”
In addition to the 1984 major upgrades, chemical phosphorous treatment was updated in 1997 and again this year with sludge dewatering added in 2012. According to Heidemann, the majority of the plant is operating with equipment and structures from the 1984 update.
As part of the upgrades planning process, Town & Country has looked at the capacity limits. The plan would increase the capacity from 458,000 gallons per day to 617,000 gallons per day and increasing the biochemical oxygen demand (BOD) capacity from just less than 2,000 pounds per day to almost 6,000 pounds per day.
“The things we really care about a lot when we design a treatment plant are BOD, suspended solids – particles in the wastewater that aren’t biodegradable, nitrogen and phosphorous,” Heidemann said, adding the city is regulated on the nitrogen and phosphorous it can release.
The base scope of the project includes site piping and updates; electrical updates; administration building renovation; influent pumping station upgrades; aeration blower upgrades; tertiary filtration replacement; UV disinfection upgrades; and aerobic digester upgrades. Heidemann said these improvements alone would cost approximately $9.36 million.
Beyond those, Town & Country Engineering created a list of four alternatives for the upgrades. Option A would entail utilizing as much of the existing facility as possible “which, inevitably, kind of forsakes some of those public safety type expansions for improvements,” Heidemann said.
Option B is an attempt to address everything to create an ideal operational treatment plant. The Town & Country Engineering representative said this does maintain using chemicals to treat the phosphorous while option C uses a biological phosphorous removal. The final alternative was a membrane bio-reactor, which was cost prohibitive.
Heidemann said the four alternatives range in cost from $9.2 million to $12.28 million. Combined with the base costs, the overall capital cost for the upgrades is $18.6 million to $21.65 million.
His recommendation is for option C, which has a projected overall capital cost of $20,171,122. The estimated operating and maintenance cost for the upgraded wastewater treatment facility is $667,863. The recommendation is based on the fact option C has the lowest feasible operating and maintenance costs, addresses all of the concerns and has the highest level of future flexibility.
The Town & Country Engineering representative also provided an overview of funding options for the wastewater facility improvements. He said Waterloo could consider loans and grants through the USDA Rural Development program and low-interest loans through the Wisconsin Clean Water Fund. Additionally, the city could explore Focus on Energy incentives and Community Development Block Grants.
Per Heidemann’s timeline, the city will hold a June 10 public hearing on the facilities plan and intent to apply for rural development funding. Information gathered at that meeting would be used in a final facilities plan that would be finalized and submitted to the Wisconsin Department of Natural Resources in July.
The final plan approval would occur in December 2022 with construction anticipated for May 2023; the upgrades would be completed by the fall of 2024.
Other council action:
• Approved a special event license for the Aug. 21 Trek 100 MACC Fund ride.
• Amended the city’s off-road vehicle ordinance relating to the use of ATVs and UTVs on city roads to align with state statutes.
• Passed a resolution supporting a strong state and local partnership for shared revenue that funds critical services.
• Approved a conditional use permit for an 800-square foot accessory building at 662 W. Madison St.