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<br />CO chapter 4
<br />ECONOMIC DAMAGES TO HOUSEHOLDS
<br />FROM MUNICIPAL WATER SALINITY
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<br />12 A summary of several previous studies begins on page 32.
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<br />130range County Water District, W;!tr.r ()ll::llity and Cnnf:llrner rmt.;: May 1972.
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<br />1.4Dlack and Veale,h, Consulting Engineers, Economic Fffccts of Mineral Content in Municip::ll W<trer Sup,plies
<br />Washmgton, D.C.: Offlce of Saline Water, May 1967, p.3.
<br />
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<br />15California Department of Water Resources, Southern District. Consumer Cm!s of Water Ouality in Domestic Water
<br />llsc.I.omnor Area Los Angeles: June 1978, p. 6.
<br />16 . .
<br />.lames M. Monlgomery, Consulting Engineers. Inc. W::lter TreRtmenl Principles ::lnd Desir" New York Joh W"I &
<br />Sons, 1986, p. 393. . . n I cy .
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<br />17 American Water Works Association, Inc., Waler Ouality and Treatment
<br />Denver, Colorado: 1971, author, pp. 299, 309-311.
<br />
<br />Corrosion and Hardness
<br />Creating Household Damages
<br />
<br />Starting with Black and Veatch in 1967, pre-
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<br />VIOUS stu les 0 water-quality-related consumer
<br />costs have focu$sed on damages to water-using
<br />appliances in households and water and waste-
<br />water pipes, increased usage of detergents, and
<br />deterioration of clothing and other textiles.
<br />With the exception of the Orange County
<br />rcport,13 these studies related damages to
<br />salinity (TDS) presumably because it was the
<br />most widely used measure of water quality con-
<br />stituents that were known to cause household
<br />damages, primarily through corrosion but also
<br />from scale deposits. To quote Black and
<br />Veatch: "In a particular water supply, it is im-
<br />practicable to determine the specific effects of
<br />minerals alone, since the effects are dependent
<br />not only upon the relative content of individual
<br />minerals but also upon many other characteris-
<br />tics of the water. Considerations of mineral
<br />effects in this report arc only broadly applicable,
<br />and overall conclusions reached do not necessar-
<br />ily apply in specific situations.,,14
<br />
<br />In 1978 a Southern District report of the
<br />California Resources agency stated: "Clearly,
<br />water quality affects the domestic consumer's
<br />water use cost, but because there are many
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<br />water quality parameters which are often inter-
<br />related, it is difficult to assign cost to any
<br />particular water quality factor.',15 These two
<br />caveats, written eleven years apart, reflect the
<br />concerns of many of the chemists and scientists
<br />interviewed during this study. That is, the
<br />assumption of a linear relationship between TDS
<br />and the economic value of various types of
<br />household damages presents a misleading pic-
<br />ture of a very complex situation.
<br />
<br />Corrosion.
<br />The corrosivity of water has been the subject
<br />of textbooks, handbooks, articles, and studies.
<br />The most recent, a chapter in a handbook
<br />prepared by Montgomery Engineers,16 states
<br />that "The rate at which corrosion takes place is
<br />a question of electrode kinetics, which are deter-
<br />mined by a very complex function of surface con-
<br />ditions, electrical behavior, and solution
<br />chemistry." The properties of water affecting
<br />corrosion rates, according to Montgomery
<br />Engineers, include dissolved oxygen, pH,
<br />temperature, velocity, chlorine residual, and
<br />chloride. Calcium carbonate (CaC03) receives
<br />attention in discussions of corrosion but its impor-
<br />tant role is a beneficial one - the formation of
<br />protective scale on metal surfaces.
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<br />The A WW A Water Quality and Treatmellt
<br />Hundbook!7 notes that dissolved oxygen serves
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