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City of Appleton
Water Treatment Facility

Project Details

The City of Appleton’s water supply and distribution system provides services to over 1,300 residents, as well as a significant industrial user. Appleton’s existing Water Treatment Facility (WTF) needed replacement as its gravity filter and chemical feed systems were significantly deteriorated.


The new location of the water treatment facility was to be adjacent to the existing facility, which required additional coordination during the during design and construction phases of the project as the site’s footprint was already constrained. To replace the existing WTF, Apex completed a preliminary engineering report and assisted the city in finding funding for the project.


One of the innovative components of the facility is the use of a Mazzei aeration system. Aeration has long been a tool for groundwater treatment, as oxygen has the ability to oxidize both iron and manganese. Previous generations of aeration treatment required a large footprint and were burdensome to operate, often requiring significant maintenance and being prone to unexpected shutdowns.

In the new Appleton WTF, the use of the new Mazzei aeration system allows for efficient oxygen transfer into water in a small footprint. The Mazzei system works by drawing in atmospheric oxygen and utilizing a pump and a Pipeline Flash Reactor to introduce oxygen into the incoming water stream. After oxygenation, the water travels to the detention tanks, where filterable iron flocs begin to form and settle out of the water. Following aeration and detention, the water is treated with an oxidant and filtered by gravity filtration. Due to the higher levels of iron found within Appleton’s wells, the filter utilizes a relatively slow loading rate of 2.0 gallons per minute/square foot. The design flow of the WTF is 600 gallons per minute.

SCADA and Remote Operation

During the design process, Apex made significant efforts to streamline staff operations by adding cell phone monitoring and alarm capabilities for the operation of the WTF. This allows operators to remotely respond to the facility and spend more time on preventative maintenance rather than emergency repairs and unscheduled maintenance. Additionally, Apex added a number of trending and operational features in the SCADA, which enable operators to easily identify and troubleshoot any alarms in real-time and optimize water treatment.


Financing for the project was provided by the Drinking Water State Revolving Fund, which consisted of a low interest loan in the amount of $6.1 million. The WTF has been operating since June of 2022.

Project Type

Drinking Water


City of Appleton


Appleton, MN

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