Water treatment is the process of cleaning water and making it safe for people to drink. Because it is a good solvent, water picks up all sorts of natural pollutants. In nature, water isn't always clean enough for people to drink.

When the microscope was invented in the 1850s, germs could be seen in water for the first time. In 1902, Belgium was the first to use chlorine to clean or treat water in a public water supply. Today, almost every city in the world treats its drinking water. Treatment includes disinfection with chlorine or other chemicals to kill any germs in the water.

The water is sampled and tested throughout the treatment plant. Sampling is performed to ensure the processes are working and that the water is safe before it leaves the plant. Skagit PUD is committed to providing customers with the safest and most reliable drinking water possible. When water leaves the treatment plant, it is as clean or cleaner than state and federal drinking water standards require.

Water Treatment Plant

Rainwater and melted snow are collected throughout the year from streams surrounding Judy Reservoir and stored in the reservoir for use by the PUD’s customers. The stored water is pumped to the water treatment plant, where impurities are removed, ensuring that the water delivered to customers is pure and safe.

Chemicals are added to the water to remove particles and provide disinfection. The water is then gently mixed in four open basins, allowing the chemicals to react with the water. The water then passes through one of eight filters. The filter media consists of a layer of sand and coal supported on gravel. Impurities are trapped in the filter and removed periodically by pumping water through the filter in the reverse direction. The filter wash water is temporarily stored in two lagoons before being returned to Judy Reservoir.

After filtration, the water is disinfected again and then flows by gravity to three steel storage reservoirs near the treatment plant. A computer system allows operators to control and monitor plant facilities at a central location. The system also provides remote monitoring, alarm indication, and data logging.