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Utilities

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.

Presedimentation Basinhighlight_off

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.

Rapid Mixhighlight_off

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.

Flocculationhighlight_off

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.

Sedimentationhighlight_off

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.

Solids Drawoffhighlight_off

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.

Filtershighlight_off

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

Clearwellhighlight_off

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.

Chlorine Contact Basinhighlight_off

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.

Storage and Distributionhighlight_off

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.