MOUNT VERNON — Estimated upgrades to the city’s water treatment plant have jumped 200 percent in the last four years, partly due to the project’s increased scope.
Work that was estimated at $15 million in 2021 is now expected to cost $45 million, a figure which does not include engineering costs.
City council members approved applying for money from the Water Pollution Control Loan Fund in 2021. However, the Environmental Protection Agency considers that agreement expired.
“We were focused only on the slice of it that was phosphorus and the digesters, so we were looking at the minimum compliance approach,” city engineer Brian Ball said Monday. “There was a lot of turnover, and we didn’t want to run in and do a project and then come back to council with a whole bunch of change orders.
“We really needed [Public Utilities Director] Aaron [Reinhart] and his team to get their feet on the ground and do a full assessment of the plant.”
While the $45 million might be sticker shock to council members, Joe Jacobs of the engineering firm Arcadis said other municipalities are paying from $38,370,000 (Circleville) to $65,000,000 (Wapakoneta).
“There’s value in the existing facilities that you have — concrete tankage, the equipment, the buildings, the structures that you have — and it’s worth keeping those existing facilities and upgrading them to give you a newer modern facility,” he said.
Paying for the treatment plant upgrades
As far as paying for the upgrades, Ball said the city has not taken on new debt in the wastewater department. The city paid one debt and will soon pay off another.
EPA and Ohio Public Works Commission grants are part of the city’s funding plan. Revenue from the New Community Authority is another source.
The NCA enables the city to levy an assessment on new developments. City officials can use the fees for new growth-related infrastructure such as water and sewer lines or road improvements.
Wastewater rates have remained steady for two years. Additionally, Ball said the city is looking at tap fees, debt replacement and 0% interest loans.
Jacobs said a rate study will provide in-depth analysis of the city’s finances and the effect on consumers.
“When that study is done, I think we’ll have some better answers on how we can afford this,” he told council.
Rationale for the upgrades
Jacobs said the city is compliant with its wastewater permit, but not necessarily industry standards because codes have changed over time. The upgrades will bring noncompliant areas up to current code.
Three main issues drive the treatment plant upgrades:
• Growth: The plant treats 3.2 million gallons of flow per day. Upgrades will raise the capacity to 4.1 million gallons of flow per day. Jacobs said planners expect 2,000 new homes over the next 20 years in addition to commercial businesses, restaurants, and industry.
• Changing regulatory environment: The EPA has added phosphorus discharge limits to permits. Upgrades will minimize the use of chemicals in the treatment process.
Solids produced by the treatment process are in liquid form with limited options for disposal. Upgrades include a de-watering function that leaves the byproduct in a cake form which the city can dispose of in a landfill.
Reinhart said that for several years the city incurred extra costs for Birch Hydra to de-water the sludge, press it, and take it to a landfill.
Disposing of liquid sludge is also limited in winter because you cannot apply it to frozen ground.
• Plant conditions: The city upgraded parts of the plant in 2012 and 2006, but the majority has not been updated since 1990. Parts of the plant date to the 1970s.
Reinhart said a wastewater plant is a very corrosive environment. Corroding pipes, falling concrete, and peeling paint are among the problems. Leaking backflow pipes, methane eating through pipes, and a 1950s boiler are other issues.
Construction timetable
Design work is about 33% complete. Jacobs anticipates bringing a contractor on board this summer and starting construction in January 2026.
Substantial completion is slated for June 2028 and final completion in August 2028.
Jacobs said the upgraded plant should last 20 years with some areas lasting 30 or 40.
Council members gave a second read to legislation authorizing the administration to apply for the Water Pollution Control Fund Loan.