volume 2 - resource management Strategies
Box 14-4 Success Story to Reduce the Cost of Water Supply
Officials from the Elsinore Valley Municipal Water District expect that a new water treatment plant will, in addition to reducing arsenic levels in the drinking water, cut the district’s dependence on water from sources such as the Colorado River Aqueduct system by 10 to 15 percent, saving ratepayers more than $1.2 million annually. This was accomplished by providing treatment to two high-producing local groundwater wells shut down in 2007 because of arsenic concentrations above the reduced maximum contaminant level of 10 ug/L. The total cost of the new treatment facility was $8.5 million; it produces water that meets the USEPA arsenic standard.
The USEPA has used the Needs Survey to establish the amount of Drinking Water State Revolving Fund (DWSRF) capitalization grants allotted to states. Table 14-8 shows the DWSRF grants awarded to California since 1997. These funds provide loans and grants to public water systems for capital projects to address public health risk problems and Safe Drinking Water Act violations.
demonstrated that caries will increase if water fluoridation is discontinued in a community for an extended period. One example is in Antigo, Wisconsin. Antigo started fluoridating its community water supplies in 1949 and discontinued it in 1960. Five and one-half years later, second graders had more than 200 percent more decay, fourth graders had 70 percent more, and sixth graders had 91 percent more decay than those of the same age in 1960 (CDPH Community Water Fluoridation Program).
Potential Costs of Drinking Water Treatment and Distribution
The cost of providing drinking water in compliance with all drinking water standards is steadily increasing due to increasing costs for energy and materials and increasing regulations requiring higher levels of treatment. Water bills reflect the costs of pumping, treating and delivery of water, as well as the operation and maintenance of the system, water quality testing and debt repayment. Water treatment costs may include the cost of chemicals, energy, and operation and maintenance of the treatment facilities. Drinking water treatment costs will vary widely from plant to plant. Many different factors can affect the cost of water treatment, including the choice of which water treatment technology to use. The design-build award price for the San Diego County Water Authority’s Twin Oaks Valley Water Treatment Plant, a new 100-million gallons per day membrane filtration plant highlighted in Box 14-4 was $157.2 million, and the annual service fee is $6.5 million, subject to contract escalators for materials and chemicals. Power (energy usage) is a pass-through cost and not included in the annual service fee. It was estimated to be $1.0 million for the first year of operation.
Table 14-5 summarizes the past and future estimated costs of treated full service water provided by the Metropolitan Water District of Southern California (MWD), which treats a blend of surface water from the Colorado River and the California Aqueduct.
caLifoRnia WateR PLan | update 2009