Cal Water doesn’t take a “one-size-fits-all” approach to water treatment; instead, we work diligently to identify the best, most cost-effective treatment required for each water source. In some areas, we operate very sophisticated facilities, including microfiltration, advanced oxidation, and ultraviolet units; in other areas, we use very simple, straightforward treatment techniques, such as granular-activated carbon filtration.

Surface water sources, such as lakes and reservoirs, typically require more complex treatment because they are exposed to the natural environment. Treatment for water from groundwater wells varies.

All of our water, whether it comes from surface water or groundwater sources, is disinfected to protect you from waterborne diseases. Disinfection of drinking water has made many once-common diseases, like typhoid and cholera, a thing of the past in the United States and other developed countries.

Chlorine is a common disinfectant used to treat the water. If you detect a chlorine taste or smell in your water, try refrigerating it before drinking. Chloramine is another type of disinfectant used in some areas. More data can be found in your annual water quality report.