Wastewater Treatment Facility Improvement Project Moves Forward

Jul. 30, 2026 —On Jul. 7, the City Commission approved a preliminary engineering service agreement with Advanced Engineering and Environmental Services, LLC (AE2S) for the Wastewater Treatment Facility improvement project.

This action is the next step in implementing recommendations from the 2023 Wastewater Treatment Facility Master Plan. Several long-term options were considered including improvements to the existing facility, construction of a new plant, and regionalization alternatives. However, the master plan identified upgrades to the current Wastewater Treatment Facility as the preferred solution.

The scope of the Wastewater Treatment Facility improvement project includes:

• Increasing wastewater treatment capacity to accommodate current needs and support future community growth.
• Replacing aging infrastructure to reduce maintenance issues and improve overall systems performance.
• Improving operational reliability, ensuring the wastewater treatment facility can function more efficiently and consistently.
• Addressing biosolids management for long-term handling and disposal needs in addition to odor concerns associated with treatment operations.
• Preparing for future regulatory requirements positioning the facility to meet changing environmental standards.

In short, the project is intended to update the Wastewater Treatment Facility, improve reliability and environmental performance, and ensure the system can serve the city’s growth well in the future.

Why is the project needed?

• The Wastewater Treatment Facility is currently at capacity during peak rain event flows. In 2028, the facility will exceed its biological treatment capacity. This doesn’t mean it will overflow, but it will be harder to treat.
• Older equipment in the facility does not allow for routine maintenance due to lack of redundancy and is also at the end of its useful life.
• Odor issues with the current solids treatment.

The estimated project cost is about $114 million. Funding will come from the City’s utility fund. Without any funding assistance, impacts on residents’ utility bill could include increasing the wastewater base and usage rate incrementally from 2026 through 2030. Currently, the projected utility rate monthly increases for a residential property using 100 cubic feet or 1 unit of water are estimated at $4.09 in 2026; $5.12 in 2027; $6.39 in 2028; $8 in 2029 and $9.99 in 2030.

It’s important to note that this effort has been in the works for several years.  

For updates, stay tuned to cityofmandan.com/news. Please contact engineering@cityofmandan.com or call 701-667-3225 with questions.