Water Treatment Plant New Construction Project


The City is constructing a water treatment plant (WTP) to lower levels on manganese in drinking water to water consumers in Northfield. The project currently is in the design phase and construction will happen in 2024 and 2025. The project is funded in the capital plan.

Need for a Water Treatment Plant

On April 5, 2022 the City Council accepted the Water System Study and its related recommendations. More information on the Water System Study can be found at the below link.

Water System Study

Recommendations from the Study

The study recommends constructing a water treatment plant that consisted of gravity filtration and reverse osmosis. A new water treatment plant will lower levels of manganese in the drinking water below the health-based guidance level of 100 micrograms per liter or less which can be harmful to infants under one year old. Additional information on manganese can be found at the below link.

Manganese in drinking water


The City is constructing the water treatment plant near its existing water tower located at 1353 Hall Avenue on land recently purchased by the City. The picture below shows the property for construction of the water treatment plant.

Water treatment plant location at 1353 Hall Avenue

Softened Water

As part of the water treatment plant, the water hardness will be reduced to roughly 90 micrograms per liter. This will make the water below the Minnesota Department of Health’s recommendation for needing to have a water softener in homes but you will still have the option to further soften your water.


Times are subject to change.

  • April 18, 2023 - Council approve Contract with recommended firm (completed)
  • April 19, 2023 - Water Treatment Plant design begins (completed)
  • Fall 2023 - Renderings due
  • November 2023 - 60% plans due and specifications due
  • February 2024 - 95% plans and specifications due
  • February/March 2024 - Project bid and awarded
  • 2024 to 2026 - Construction
  • 2026 - Water treatment plant operational, treated water to residents


The project is going to cost roughly $36,450,000 with the construction of the new water treatment plant and new roads that are being constructed for access to the property.

The water treatment plant itself will cost an estimated $33,450,000 to design and construct.

Rates for Customers

The project will increase rates for residents, however, residents will see the benefits of safer and cleaner drinking water.  Water rates will increase by 20% for the next three years, then 15% for one year and 5% for the following years based on this project or roughly $15.00 per month for the average water user for 2022 rates versus 2026 rates.  Wastewater, stormwater and garbage rates are not affected by the construction of the water treatment plant.

Federal Funding

The City has applied for federal funding which the city’s project was approved as a project in 2022 and now is seeking the appropriations or funding by the federal government. Whether or not the City receives the federal funding, the project is moving forward. Below is a graph showing the adjusted rates if the City does or does not receive federal funding in comparison to similar cities that soften the water. Rates are being adjusted based on the City receiving federal funding.

WTP Projected Rates

Northfield $40.09, Mankato $36.04, St. Peter $50.01, Fairmont $73.41, Northfield with federal funding $29.19

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Bolton & Menk, Inc. proposal

Water System Study