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Water Treatment Process#

The Fort Collins Utilities Water Treatment Facility, staffed 24 hours a day by state-certified operators, chemically and physically treats raw (untreated) water to make it safe to drink. Our treated drinking water and corrosion control consistently surpass state and federal standards for purity.

The facility has the ability to treat up to 87 million gallons of water a day. On average in 2020, it treats 23 million gallons a day and peak production was 49 million gallons in one day.

The diagram and descriptions below explain each major section of the treatment process.

Before raw Poudre River water is piped to the treatment facility, it passes through the presedimentation basin. The basin screens out large debris and settles out sand and silt.

The water is mixed at high speed while aluminum sulfate (alum) is added to chemically combine with contaminants and neutralize the electrical charges. This allows the impurities to begin coagulating, or forming small particles that can more easily be removed.

The small contaminant particles formed in the rapid mix begin to collect and form larger particles, called floc, which are heavier than water. The water is mixed slowly at different speeds to assist floc formation, and a polymer is added to strengthen the floc.

The larger suspended particles (floc) formed in the flocculation basin settle to the bottom of the basin. Inclined plates are used to speed the settling. Clear water is skimmed off the top of the basin.

After settling to the basin's bottom, the floc is scraped into a pit and drawn off through a pipeline. The resulting material, residual solids, are spread out in a shallow pond, where they dry out for easier handling.

The clarified water flows through layers of sand and anthracite coal to remove any remaining impurities.

Is a small holding tank where the finishing process takes place, ensuring that the water is safe and healthy to drink. Chlorine is added as a disinfectant according to state and federal regulations. Fort Collins citizens mandated the addition of fluoride in the 1960s to enhance dental health. Lime and carbon dioxide are added to make the water less corrosive to home plumbing systems.

To ensure that the drinking water is adequately disinfected before reaching the first customer, the treated water flows through the serpentine-like Chlorine Contact Basin before going into storage, to provide adequate time for the chlorine to do its job disinfecting the water.

Once water is treated and ready for drinking, it is stored in underground reservoirs until needed. The reservoirs provide storage for 37 million gallons of water that can be used during high-use periods. Underground pipes carry the water from the storage reservoirs to your tap.

See How Our Water Compares#

Check out this bottled water comparison from our Water Quality Lab.


Did You Know?

Shrubs and trees require less water than bluegrass, so it's best to water them separately.

Rebates are available for 1.1 gallons per flush, WaterSense-labeled toilets.

Information about business-related programs and rebates regularly goes out in the Keep Current e-newsletter.