chapter 14 - Drinking Water treatment and Distribution
Table 14-3 Treatment plants on California public water system sources
Type of conta Surface water1 Nitrate Arsenic Radiological
Number of treatment plants 660 150a 65a 15a
Volatile and synthetic organic chemicals Aesthetic water quality Note: These estimates are based on a survey of CDPH offices and from CDPH records.
Surface water, as defined under the California Surface Water Treatment Rule (Cal. Code Regs., tit. 22, § 64651.83.) means “all water open to the atmosphere and subject to surface runoff...” and hence would include all lakes, rivers, streams and other water bodies. Surface water thus includes all groundwater sources that are deemed to be under the influence of surface water (i.e., springs, shallow wells, wells close to rivers), which must comply with the same level of treatment as surface water.
Includes chemical removal and blending treatment facilities
consumption. Water recovery is the water converted to potable water in a treatment plant—the remainder is a residual or waste stream. It is important for treatment processes in water-short areas to maximize the amount of a water supply that can be converted to potable water by reducing the amount that is discharged as a waste such as water used to backwash, or clean, filter vessels.
Public water systems in California use more than 17,000 groundwater wells and surface water supplies to meet the water supply needs of consumers. Some of these need treatment to meet either aesthetic quality or to remove or inactivate contaminants prior to consumption. These could include minerals, metals, chemicals from industry or agriculture, pathogens and radiological constituents. Information on the number and type of water treatment plants installed on public water system sources in California is shown in Table 14-3.
Fluoridation of community drinking water has been practiced in the United States for more than 60 years. It is accepted as a safe and effective public health practice for people of all ages. The previous five Surgeons General have recommended communities fluoridate their water to prevent tooth decay. California’s fluoridated drinking water act, Assembly Bill 733, became law in 1995, requiring water systems with 10,000 or more service connections to fluoridate once money from an outside source is provided for both installation and operation and maintenance costs. CDPH is also responsible for identifying funds to purchase and install fluoridation equipment for public water systems.
During fluoridation treatment of public water system supplies, many water systems provide optimal fluoridation treatment. Optimal fluoridation means that the water treatment facility and distribution system are able to provide a consistent level of
caLifoRnia WateR PLan | update 2009
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