Water Sources, Treatment, and Distribution

Water Sources, Treatment, and Distribution

Arvada's water system annual operation and maintenance budget is over $18 million.  Sixty employees make sure that water is properly treated, adequately tested, and efficiently distributed to homes and businesses.  Below is a description of Arvada's raw water sources that are used to make treated drinking water, Arvada's water treatment process, and some of the components needed to deliver drinking water to customers.

Drinking Water Sources

The City has 24,900 acre-feet (AF) of water rights, 19,500 AF (78%) is supplied from Denver Water and 5,400 AF (22%) comes from Clear Creek. One acre-foot is 325,851 gallons.  An average family uses approximately 0.4 AF per year.

Denver Water provides Arvada with water from its Moffat Collection System.  The water is collected in the Williams Fork, Winter Park, and Fraser areas and transferred to the east slope through the Moffat Tunnel. Then water is transported down South Boulder Creek to Gross Reservoir in the Boulder Mountains. From Gross Reservoir the water flows down south Boulder Creek through El Dorado State Park where the South Boulder Diversion Canal takes the water to Ralston Reservoir. Water from Ralston Reservoir flows through two pipes directly to Arvada's Ralston Water Treatment Plant (RWTP) that treats raw water to produce drinking water. See related links for a water supply diagram.

Drinking Water Treatment

In a normal year, the City treats and delivers over six billion gallons of water using the Arvada and Ralston Water Treatment Plants.  The Ralston Water Treatment Plant (RWTP) is the main water treatment plant.  It operates all year long and can treat 36 million gallons per day. The RWTP receives its water from Denver Water Board's Moffat Tunnel System.  The Arvada Water Treatment (AWTP) is only used for peak flows, normally April - October, and can treat 16 million gallons per day.  The AWTP's source of supply is the Arvada / Blunn Reservoir which receives water from Clear Creek and Ralston Reservoir.

Both treatment plants use the same treatment process:

When the water enters the plant, a coagulant is added which allows impurities in the water to clump together forming a floc. The water then enters several large chambers where it slowly circulates, allowing the large floc to settle out and is removed from the water. The water is then sent through mixed media filter beds consisting of layers of gravel, sand and anthracite for the final cleaning. The water is adjusted for proper pH, disinfected, has fluoride added, and is then sent into the distribution system for delivery to our customers. See related links for a water treatment diagram.

The drinking water distribution system is mostly gravity-fed, with only one pump zone. It contains:

  • 531 miles of water lines
  • 9 water tanks
  • 13,700 valves
  • 4,534 fire hydrants

To keep the pipes that transmit drinking water clean, occasional line flushing is required. Water system flushing can occur on a routine basis from fire hydrants for maintenance purposes, or might occur after pipe repair to assure that the water system contains only safe drinking water.

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