Wastewater Treatment

Boxelder Sanitation District operates a state of the art Biological Nutrient Removal (BNR) Wastewater Treatment Facility. The facility was designed to remove pollutants conventional wastewater treatment facilities cannot, such as Phosphorus and Inorganic Nitrogen to meet strict water quality limits to protect public health and our Poudre River.

So how does it work?

wastewater process

  • When you flush the toilet, wash clothes, or drain the sink, the water is discharged to the collection system where the water is carried to the treatment facility.
  • Screening of the sewage is the first step as it reaches the facility to remove debris such as plastics, paper products, and large objects.
  • Next the sewage is carried by pumps to the anaerobic zone of the facility where the sewage is mixed with a biomass of naturally occurring microorganisms to remove phosphorus, a leading cause of algal blooms and oxygen depletion in streams.
  • The mixture of microorganisms and sewage is then directed to the aerobic zone of the facility where primary treatment is completed by the addition of oxygen. Ammonia is removed by the addition oxygen which creates a by-product of nitrate.
  • The microorganisms then consume the nitrate as a food source to survive. Nitrate is a pollutant that causes adverse conditions in the environment and public health and is critical to be removed in the treatment facility.
  • Once the pollutants have been removed from the wastewater, the biomass flows to clarifiers where the biomass of microorganisms settle to the bottom of large tanks to be recirculated to the beginning of the facility to treat additional wastewater.
  • The treated water known as effluent flows through an ultraviolet disinfection process where viruses and coliforms are destroyed prior to discharging to the Boxelder Creek, and ultimately our Poudre River.

Boxelder Sanitation District is proud to be on the leading edge of maintaining regulatory compliance through excellence in operations and protecting public health and the environment.


Rotifer – Wastewater Treatment Microorganism


Water Bear – Wastewater Treatment Microorganism