October 28, 2026

As construction continues on our treatment plant in West Bountiful, we wanted to shine a spotlight on one of the biggest additions to the facility: the Moving Bed Biofilm Reactor (MBBR)!

The MBBR is designed primarily to reduce the amount of ammonia in wastewater to meet new nutrient limits mandated by the Utah Division of Water Quality. Ammonia can be toxic to aquatic life, and excessive amounts entering rivers and streams can harm fish and other aquatic species. Excess nutrients can also contribute to harmful algal blooms, which threaten water quality and aquatic ecosystems.

MBBR technology has been used in wastewater treatment since the 1980s. The first full-scale MBBR installation was built in Norway in 1985. Compared to many of our plant processes, which date back to 1960, this is relatively new technology! Since its introduction, MBBRs have been adopted around the world as an effective and reliable wastewater treatment solution. For the District, it will provide the ammonia removal needed to meet lower permit limits – something our current wastewater treatment processes cannot adequately achieve.

So, how does an MBBR work? The MBBR is a large tank, filled with thousands of small, free-floating plastic pieces called media that are essential to the process. Their specially designed shapes provide a large surface area where beneficial microorganisms can grow and form a layer called a biofilm. As wastewater flows through the tank, large devices called aerators act like giant bubblers that supply air to keep the water moving and ensure the bacteria constantly meet fresh wastewater and oxygen. Specialized bacteria convert ammonia into nitrite and then nitrate through a process called nitrification. Then, through a process called denitrification, other microbes convert nitrate into nitrogen gas, which bubbles up and is safely released into the atmosphere.

Why does this matter? By reducing ammonia levels before the treated water is released, the MBBR helps protect aquatic life and improve the quality of the water entering our environment.

At the end of the day, wastewater treatment is about more than a process. It’s about caring for our community by responsibly treating the wastewater we all generate and protecting the environment we share. While much of our facility has served the community for decades, this new addition – funded along with other improvements by fees and taxes – is an important step in upgrading our treatment plant to ensure we can continue providing reliable wastewater treatment. Together, we’re investing in an essential service that protects our community today and helps ensure a cleaner, healthier future for generations to come.

 Want to see more of the work taking place at the North Plant? Check out our North Plant Construction page.