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.

How does the wastewater treatment process work?

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 Boxelder wastewater treatment facility. Once it arrives at the plant, here’s the journey it takes:

  1. The first step of the process is screening, which removes large plastics, paper products and other items that shouldn’t be there. 
  2. Next the sewage is carried by pumps to the anaerobic zone of the facility where naturally occurring microorganisms (we call them “bugs”) remove toxic phosphorus that’s dangerous to our rivers. 
  3. The mixture of microorganisms and wastewater is then directed to oxidation ditches where the “bugs” deconstruct matter and consume waste materials through a biochemical process. Oxygen is added to remove ammonia creating a nitrate by-product. 
  4. 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.
  5. 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.
  6. Finally, the treated water, known as effluent flows, through an ultraviolet disinfection process to eliminate any potential leftover organisms. The treated water is then discharged 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.


What part do I play in the process?

What you flush down your drains and toilets makes a huge different for our wastewater system. You can help keep things flowing smoothly for everyone by only flushing the Three Ps – pee, poo and toiler paper. These three things can breakdown properly during the treatment process. Anything else may result in a sewer overflow in your home, or a blockage known as a “fatberg” in our sewer lines. Check out our What not to Flush for more information.

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