Treatment Process Change for Cal Water’s Oroville Water System
At Cal Water, providing safe, clean drinking water for our Oroville customers is our top priority. We wanted to notify you of a change we will be making to the treatment process, which will still provide safe, clean water to you. Per the City of Oroville’s Resolution No. 9284, passed on July 16, 2024, and the California Public Utilities Commission’s (CPUC) approval in Decision 26-02-039 on February 26, 2026, we will be discontinuing the addition of fluoride to your tap water.
As background, in 1957, the Oroville City Council gained the approval of the CPUC to mandate that Cal Water’s Oroville District add fluoride to the drinking water of its customers. It was a decision made based on the best available data at the time and with the health of citizens in mind. Since then, we have added fluoride according to the safety guidelines established by the health experts at California’s Division of Drinking Water (DDW), which sets drinking water standards for health and safety.
Since 1957, fluoride has become more readily available in other sources. According to the American Dental Association (ADA), topical application of fluoride (i.e., brushing, rinsing, etc.) has been found to be the most effective way to prevent dental caries, and is recommended at higher concentrations than are safe for ingestion. With this in mind, Oroville’s City Council passed Resolution No. 9284 to direct staff to work with Cal Water and the CPUC to discontinue fluoridation of Cal Water’s drinking water.
The CPUC recently approved Cal Water’s application to discontinue fluoridation per the City’s resolution. We have also worked with DDW to change our operating permit to reflect that we will no longer be adding fluoride to our drinking water. And, we have developed an outreach plan to communicate this change, as well as a flushing plan to move the fluoridated water out of the system over the course of several weeks.
During the conversion, you may see Cal Water operators flushing the distribution system, analyzing water quality with field test kits, and collecting samples for additional laboratory analysis. You may notice a different taste or odor, which is due to moving the water rapidly through the pipes; the fluoride itself is colorless and odorless, and you will not be able to notice changes of concentration in fluoride. We will be carefully monitoring the water quality during this time, and you may use and drink the water as normal. The fluoride concentrations will never go up during this process; they will decrease at different rates depending on the area of our distribution system that you are in.
If you have any questions or concerns, including any water quality concerns during flushing, please call our Oroville office at (530) 533-4034.
