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<br />from toilets, kitchen sinks, dishwashers, or laundry
<br />water from soiled diapers, is not suitable for reuse
<br />because it may contain bacterial contaminants,
<br />grease or residues of detergents that are harmful to
<br />plants.
<br />
<br />During the 1976-1977 drought, water conservation
<br />advice often recommended that homeowners use
<br />graywater from laundering
<br />and bathing on outdoor plants.
<br />Graywater captured after in-
<br />door use contains nutrients
<br />that can be beneficial to many
<br />landscape plants. Graywater
<br />is applied through subsurtace
<br />irrigation systems and can be
<br />used to water all plants except
<br />vegetable gardens. (Some
<br />acid.loving plants such as
<br />azaleas and camellias are
<br />generally not suitable for
<br />irrigation with alkaline gray-
<br />water.) However, indiscrimi.
<br />nate use of graywater some-
<br />times had adverse etfects on
<br />some plants, and critics
<br />warned the practice could
<br />contaminate local water sup.
<br />plies or inadvertently spread
<br />disease.
<br />
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<br />
<br />I"dustrial und commercial
<br />j(lciliries IIse about 26
<br />percellt of urban applied
<br />\I'afel: Water IIsage ill
<br />industrial seltiJlgs varies
<br />lI'idely, from product
<br />lI'ashillJ.; iI/food
<br />proCl'ssillg to cooling
<br />rowers ill commercial and
<br />institl/tioJlal buildings.
<br />Sun'e."s by urban Imter
<br />agl'lIcies indicate potential
<br />lI'atel' use reductions at
<br />industrial sites ranging
<br />fin/1/ 25 percent to 90
<br />pcrccm (~rprel'ious llse,
<br />
<br />14
<br />
<br />Those concerns led to enact-
<br />ment in 1992 of state legisla-
<br />tion to develop standards for
<br />household use of graywater
<br />for irrigation. The standards
<br />set specifications for plumbing
<br />design and equipment to ensure that graywater is
<br />safe for intended uses. Because they require dual
<br />piping. surge tanks and distribution piping, graywater
<br />systems can be expensive to install. Plumbing
<br />parts alone for a system designed to serve a three-
<br />bedroom residence with four occupants cost
<br />an estimated 5750. Permit fees, professional
<br />installation of the system, and maintenance costs
<br />are extra.
<br />
<br />Because of the expense involved in dual piping,
<br />experts believe graywater systems are most
<br />likely to appear in new construction in areas where
<br />water supply is unreliable and in commercial
<br />landscapes where substantial water savings are
<br />possible. The California Urban Water Conservation
<br />Council considers graywater use to be a potential
<br />BMP, but has taken no action to elevate it to a
<br />mandatory BMP.
<br />
<br />URBAN MOU AND BMPs
<br />
<br />
<br />Another key urban water conservation eHort is a
<br />series of protocols known as "Best Management
<br />Practices" (BMPs). 16 measures to which many
<br />urban water suppliers have committed in principle.
<br />BMPs predate, but are analogous. to the agricultural
<br />EWMPs. Among the conservation measures
<br />included in the BMPs are programs to promote
<br />installation of low. flow showerheads and ultra-
<br />low-flush toilets, wastewater recycling, aggressive
<br />leak detection, water meters for all new connections
<br />and landscape water conservation programs. It is
<br />estimated that adherence to the BMPs by all urban
<br />water agencies could reduce urban water use by up
<br />to 1 million acre-feet per year.
<br />
<br />For residential water users, experts agree that giving
<br />customers incentives to replace inefficient older
<br />toilets and showerheads achieves quick results in
<br />terms of water savings. For instance, the Goleta
<br />Water District in the water-short Central Coast was
<br />able to avoid drastic rationing steps during most of
<br />the 1987-1993 drought by subsidizing the replace,
<br />ment of old toilets with ultra.low-flush models. Some
<br />urban water districts, such as the Irvine Ranch Water
<br />District, have demonstrated impressive water
<br />savings by working with residential customers, the
<br />landscape industry and commercial landscape
<br />customers on pricing incentives to reduce landscape
<br />irrigation water use.
<br />
<br />Although about two-thirds of the state's 350 urban
<br />water suppliers signed a 1991 MOU to implement
<br />BMPs. according to DWR, implementation is spotty.
<br />Based on initial reviews of urban water management
<br />plans submitted so far, DWR officials say few urban
<br />water agencies have taken steps to effectively
<br />implement BMPs. When DWR reports to the state
<br />Legislature on implementation, it is expected that
<br />only a few agencies will have earned a Level 3
<br />designation, which means they are close to tulty
<br />implementing the BMPs. DWR lacks the legal
<br />authority to compel water agencies either to adopt
<br />BMPs or to implement them fully. Under the Urban
<br />Water Management Planning Act, only a citizen
<br />lawsuit against a specific water agency can seek to
<br />compel adherence to BMPs.
<br />
<br />
<br />Urban water agencies regularly update their water
<br />management plans, most recently in 1995, and they
<br />also are required to develop water shortage contin-
<br />gency plans to prepare for the next drought or other
<br />natural disasters that cause water shortages. With
<br />permission from local water agencies, DWR is build.
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