Water Quality

Your Drinking Water

Judy Reservoir is filled with water that has been diverted from four creeks in an uninhabited, nine square mile, forested area in the Cultus Mountain watershed. Water is also pumped from the Skagit River to Judy Reservoir during critical periods or when the streams run low. Water is pumped from Judy Reservoir to the adjacent water treatment plant, which was placed into service in 1990. The treatment plant is staffed 24 hours per day, 365 days per year, by certified water treatment plant operators trained in the water treatment profession.

The treatment process begins with primary disinfection using chlorine dioxide. Then, agents are added to cause small particles to combine into larger clusters that can be more easily settled and filtered from the water, a process called coagulation and flocculation. The water passes through filters of anthracite and sand, removing suspended particles and impurities. After leaving the treatment plant, the pH is adjusted, and the water is disinfected using chloramines. The levels of additives are monitored constantly to ensure proper dosages are maintained.

The treatment plant was designed to produce about 18 million gallons of drinking water each day. Skagit PUD expanded its capacity at the water treatment plant in 2009 to 30 million gallons of water each day. This will satisfy the needs of our rapidly growing area. Treated water flows to the Skagit Valley customers by way of two major transmission pipelines that are part of the 650 miles of pipelines that serve PUD customers.