LOS ANGELES--The Metropolitan Water District of Southern California joined a majority of the nation's water utilities in adding fluoride to the drinking water for 18 million Southern Californians on Oct. 29.
Beginning with the Henry J. Mills Water Treatment Plant in Riverside, Metropolitan rolled out fluoridation at its five treatment plants over a six-week period. Metropolitan will supplement the trace amounts of naturally occurring fluoride in the district's imported source waters from the Colorado River and Northern California to levels promoted by the American Dental Association and national public health groups to help prevent tooth decay.
In line with recommendations from the California Department of Public Health, as well as the U.S. Centers for Disease Control and Prevention, Metropolitan will adjust the natural fluoride level in its imported supplies--ranging from 0.1 to 0.4 parts per million--to the optimal range for dental health of 0.7 to 0.8 parts per million.
However, actual fluoride levels consumers realize at the tap may be less depending on how much their retail agencies blend Metropolitan deliveries with local supplies. Fluoride levels in drinking water are limited under California state regulations at a maximum level of 2 parts per million.
Fluoridation at the Mills treatment plant, which provides supplemental water to southwest Riverside County, will be followed Nov. 12 at the F.E. Weymouth plant in La Verne, primarily serving Los Angeles County; Nov. 19 at the Robert B. Diemer plant in Yorba Linda, treating supplies for Orange County; Nov. 26 at the Joseph P. Jensen plant in Granada Hills, serving Los Angeles and Ventura counties; and Dec. 3 at the Robert A. Skinner plant, serving southwest Riverside and San Diego counties.
In adding fluoride, Metropolitan will becomes the latest urban water supplier to add the cavity-fighting agent to its treatment processes. Today, 43 of the largest 50 cities in the United States fluoridate drinking waters.
Metropolitan's addition of fluoride follows the policy adopted by MWD's Board of Directors in February 2003, directing fluoride to be added to the district's treatment processes.
Metropolitan's board had been examining fluoridation since Gov. Pete Wilson in October 1995 signed a state law that conditionally mandates fluoridation of any public water supply that has at least 10,000 service connections or customers.
Although Metropolitan was not required to fluoridate under the law, local public health officials continued to push for region-wide fluoridation to maximize the financial and dental health benefits.
Prior to the adoption of Metropolitan's policy, seven public health officials representing the six Southern California counties in MWD's service area urged the district's board to consider adding fluoride to district supplies.
The health officials testified that adding fluoride at Metropolitan's treatment plants was the most cost-effective method to fluoridate regionally.
The California Dental Association Foundation, a nonprofit public benefit corporation, in cooperation with a statewide fluoridation task force, provided Metropolitan $5.5 million in grant funds to design and construct fluoridation facilities at its treatment plants.
For more information on the fluoridation of Metropolitan's treated water supplies, visit the district's Web site at www.mwdh2o.com.
