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Water Treatment

The city has two water treatment plants, treating approximately 6 billion gallons of drinking water per year. Drinking water is delivered through 450 miles of pipeline to homes and businesses within the 26 square mile service area (see map) and is used for drinking water, irrigation, and firefighting. Average water use is 10 million gallons per day in the winter and 28 million gallons per day in the summer.

Betasso Water Treatment Plant is located in the foothills west of Boulder and treats water from Barker and Lakewood Reservoirs, which are fed by Middle Boulder Creek and North Boulder Creek. Betasso is currently being renovated to replace aging equipment and support updated treatment processes. Learn more here .

Boulder Reservoir Water Treatment Plant treats water from Boulder Reservoir and the Boulder Feeder Canal (May through October), which are operated by Northern Colorado Water Conservancy District . Boulder Feeder Canal delivers water from the upper Colorado River via Carter Lake.


Water Treatment Process

Water treatment is a multi-step process. Large debris such as sticks and plants, are screened from the water before it is piped to the water treatment plants. To remove smaller particles, aluminum sulfate is added to the water as a coagulant. The Betasso water treatment plant uses a gravity settling process to remove the coagulated particles. At the Boulder Reservoir water treatment plant, dissolved air flotation (DAF) technology is used to remove the coagulated particles from the water. During the DAF process, the particles bind to micro oxygen bubbles injected into the water, which then float to the surface, and are removed from the water prior to further treatment. After coagulation and settling/DAF treatment, the water flows through a dense layer of sand, anthracite, and gravel, filtering the smallest remaining particles from the water. The final steps of the water treatment process include disinfection (with chlorine), corrosion control to adjust the water alkalinity and minimize corrosivity to pipes, and fluoride addition for dental health.

Schedule a Tour

Touring the water treatment plants provides customers with a better understanding of where their drinking water comes from and how it is treated prior to distribution. Free tours are available Monday through Friday, 9 am to 4pm. Two weeks notice is required. Tours at Betasso Water Treatment Plant are not available until after the capital improvement projects have completed.