The regional agency that supplies drinking water to Santa Margarita Water District announced this week it will slightly reduce the amount of fluoride in its water effective June 1.
Under a 1995 California law, water systems with 10,000 service connections must fluoridate their supplies if funding is available; Metropolitan Water District of Southern California (MWD), which supplies water to SMWD and 19 million people in Southern California, began adding fluoride in 2003.
MWD had adjusted the natural fluoride level in its water, which ranges from 0.1 to 0.4 parts
per million, to 0.8 parts per million in line with recommendations from the California Department of Public Health, as well as the U.S. Centers for Disease Control and Prevention.
On April 27, the U.S. Department of Health and Human Services (HHS) released the final Public Health Service recommendation for the optimal fluoride level in drinking water for a single level of 0.7 mg/L of fluoride, which replaces the previous temperature-dependent range of 0.7 to 1.2 mg/L.
Per the state’s Division of Drinking Water (DDW) recommendations, starting June 1, MWD will reduce the current fluoride target of 0.8 parts per million to the new optimal fluoride target of 0.7 parts per million, with a new control range of 0.6 to 1.2 parts per million, leaving Metropolitan’s treatment plants.
Based on SMWD’s distance from MWD treatment plants, the new fluoride level will reach South Orange County a few days after the change. SMWD’s water-quality testing has shown fluoride levels between 0.7 and 1.0 parts per million.