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Chapter 5

Water Supply and Water Quality

KEY IDEASKEY IDEASKEY IDEASKEY IDEASKEY IDEAS

• Florida’s future depends on a continuedsupply of adequate amounts of clean freshwater for human consumption and fornatural systems.

• The amount of water changed by humanactivity is far greater than the amount ofwater directly used by humans.

• In some places in Florida, the demand forfresh water is greater than supply.

• Florida’s water management districts arecommitted to finding new ways to meet thedemand for water.

• Pollution is anything that causes animbalance in or harms the naturalenvironment.

• Scientists use a number of tests andmeasures to determine water quality.

• Pollution takes two main forms: point sourcepollution and non-point source pollution.

VOCABULARYVOCABULARYVOCABULARYVOCABULARYVOCABULARY

Aquifer storage andrecovery

Best managementpractices

Conductivity

Desalination

Detention pond

Dissolved oxygen

Drip irrigation

Environmental pollution

Filtration

Impervious surface

Irrigation

Non-point sourcepollution

“Not only is the level of the water in the global well getting low, the water is also polluted, sometimes to the point where it is no longer drinkable.” — Julie Stauffer, The Water Crisis, 1998, p. xi

Florida’s future depends on a continuedsupply of adequate clean fresh water. Waterquality and water quantity are bothimportant: it does little good to have vastamounts of polluted water. Plants, fish andother animals, as well as humans, all requireadequate amounts of clean water.

The quantity of water changed by humanactivity is far greater than the amount ofwater directly used by humans (Betz 1984).Each time humans withdraw ground water orsurface water for a particular purpose, wasteis generated. Household use generateswastewater from toilets, sinks, showers,bathtubs, dishwashers and washingmachines; phosphate mining generatesphosphate slime; manufacturing generateschemical waste; irrigation generates runoffcontaining nutrients from fertilizers, as wellas from pesticides and herbicides. Even raincontains impurities generated by burning offossil fuels, dust and ash. It’s not enough to becareful about the amount of water we use. Wemust also do our best to return it to theenvironment as pure as possible.

Some places in Florida, such as theFlorida Keys and St. Petersburg, never hadenough fresh water to support large-scaledevelopment. Each day, 16 million gallons ofwater flow from wells near Homestead, onthe mainland of Florida, to the Florida Keys.Water travels through a 130-mile-longpipeline supplying water all the way to KeyWest. St. Petersburg, “a peninsula on apeninsula” with the highest populationdensity in Florida (3,100 persons per squaremile), ran out of water in the 1920s and nowrelies on well fields in Hillsborough and Pascocounties. In other places, water use is rapidlysurpassing inexpensive water supply.

“Although water is part of a global system, how it is used and managed locally and regionally is what really counts. Unlike oil, wheat and most other important commodities, water is needed in quantities too large to make it practical to transport long distances.” — Sandra Postel, Last Oasis, 1992, p. 23

Nutrients

pH

Point sourcepollution

Pollution

Public supply

Reclaimed water

Retention pond

Reuse

Turbidity

Wastewater

Water Use CautionAreas

Xeriscaping

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Fast-growing Charlotte County gets waterfrom DeSoto County, and Sarasota Countygets water from wells in Manatee County.Other parts of Florida are also experiencingshortages. Water levels in the Floridanaquifer in coastal Walton, Okaloosa andSanta Rosa counties in the Panhandle havedropped as much as 100 feet below sea level.Near Orlando, groundwater levels havedropped 25 feet in places, and the flow insprings in the Wekiva River basin hasdiminished. Titusville on the east coast hasnotified the St. Johns River WaterManagement District that by 2010 it will nothave enough water to meet the needs ofprojected growth.

Water resource caution areas, (alsoreferred to as water use caution areas),places where water is either scarce orcontaminated, now cover thousands ofsquare miles throughout the state. The mostextensive water resource caution areas are insouthwest Florida in all or parts of Pasco,Pinellas, Hillsborough, Sarasota, Charlotte,DeSoto, Polk and Highlands counties.

Florida’s water management districts arecommitted to finding new ways of meetingthe demand for water. Providing high-qualitydrinking water is expensive, and using thatwater to meet all water needs is unnecessary.Floridians will increasingly use alternative

Water Resource Caution Areas(WRCAs) in Florida

NorthwestFlorida WMD

SuwanneeRiver WMD

St. JohnsRiver WMD

SouthwestFloridaWMD

SouthFlorida WMD

District boundaries

Water resource caution areas

supplies of water to meet nonpotabledemands, instead of seeking new, often far-away and more pristine sources. Reclaimedwater, for example, can be used to irrigategolf courses and landscaping, as well as inindustrial processes and power generation.The use of desalination, particularly ofbrackish ground water, is increasing inFlorida’s populated areas. Another

Source: Florida’s water managementdistricts, February 1995

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way to increase water supply is conservationand increased efficiency. Household fixtures,such as toilets and showers, that save waterare now available. Landscaping with native,drought-tolerant plants (Xeriscaping) alsohelps conserve water. Agriculture andindustry have begun to implement new and

more efficient ways of using water. Watermanagement districts have begun to explorethe option of storing water in aquifers duringtimes of abundant rainfall and withdrawingit during times when rainfall is scarce, aprocess known as aquifer storage andrecovery (see illustration, page 90).

Water UseWater UseWater UseWater UseWater Use

DEFINITIONSDEFINITIONSDEFINITIONSDEFINITIONSDEFINITIONSAgencies, such as the U.S. Geological

Survey (USGS) that keep track of how muchwater is used for various purposes,distinguish between withdrawal uses,consumptive uses and nonwithdrawal uses.Withdrawal is the act of taking water from asource for storage or use. In many cases,water is withdrawn from its source andreturned to its original source within a shortperiod of time. Water withdrawn from ariver to cool power plant equipment andthen returned to the river is an example.Some of the withdrawn water is consumed;that means the water is no longer availablefor immediate reuse. Evaporation, planttranspiration and incorporation into aproduct are all consumptive uses. Whenwater is withdrawn for irrigation, forexample, some evaporates, some transpiresand some is incorporated into plants. Theremainder may return to the surface wateror groundwater source from which itoriginated. Nonwithdrawal uses include useby natural systems, recreation use and usefor transportation.

TYPES OF USESTYPES OF USESTYPES OF USESTYPES OF USESTYPES OF USESThe USGS collects and compiles water

withdrawal data in Florida and throughoutthe United States. USGS distinguishesbetween saline water and freshwater useand between surface water andgroundwater use. Data are collected in thefollowing water use categories: public supply,domestic self-supplied, commercial-industrial self-supplied (including mining), agricultural self-supplied (including

livestock), recreational irrigation and power generation (cooling of

thermoelectric power plants).

Public supply includes systems thatserve more than 400 people or use morethan 10,000 gallons of water each day.Public-supply systems provide water tohouseholds, businesses and industries.Domestic self-supplied is water withdrawnby the user for household use, usually fromindividual wells. Agricultural self-suppliedincludes irrigation, the process ofsupplying water to areas of land to makethem suitable for growing crops, sod andlandscaping plants, as well as water forlivestock.

Recreational irrigation was a new wateruse category in 1995. It includeswithdrawals for the irrigation of land usedfor recreational purposes. Golf courses arethe largest users in this category. Before1995, recreational irrigation was includedunder agricultural self-supplied.

HOW MUCH IS A MILLIONHOW MUCH IS A MILLIONHOW MUCH IS A MILLIONHOW MUCH IS A MILLIONHOW MUCH IS A MILLIONGALLONS OF WATER?GALLONS OF WATER?GALLONS OF WATER?GALLONS OF WATER?GALLONS OF WATER?

Agencies that keep track of water useusually do so in million of gallons used eachday (mgd). Visualizing such a large numberis difficult. Think about a bathtub or aswimming pool. A bathtub can hold about50 gallons of water. You would have to take20,000 baths before you used a milliongallons of water! How big do you think aswimming pool would have to be to hold amillion gallons of water? It would have to be10 feet deep, 50 feet wide and 267 feet long!(USGS 2001)

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Total and Per-Capita Global Water Withdrawals

Water Withdrawals in the United States

Source: Gleick 1998

Source: Gleick 1998

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1 automobile

900 kg of paper for bags

1 kg of cotton

1 kg of aluminum

1 kg of beef

1 kg of rice

1 kg of steel

1 liter of gasoline

400,000

32,800

8,800

8,800

7,000

5,000

2,200

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Liters of Water Typically Used to Produce Products in the United States

Domestic Water Use ( liters )

showering 5 minutes

brushing teeth

washing hands

flushing standard toilet

flushing low-flow toilet

washing one load of laundry

running dishwasher

washing dishes by hand

95

10

7.5

23

6

151

19

114

WORLDWIDE WATER USEWORLDWIDE WATER USEWORLDWIDE WATER USEWORLDWIDE WATER USEWORLDWIDE WATER USEAND TRENDSAND TRENDSAND TRENDSAND TRENDSAND TRENDS

Agriculture is the single largest userof water in Florida and in the world.Two-thirds of all the water withdrawnworldwide from surface water andgroundwater sources is used foragriculture (Postel 1992). Many of theworld’s farmers irrigate in the same waystheir ancestors did thousands of yearsago: by flooding or channeling wateracross the land. Postel (1992) estimatesthe overall efficiency of agriculturalwater use worldwide is only 40 percent,meaning that over half of all waterdiverted for agriculture never producesfood.

Industry also uses vast amounts ofwater. Even if water is not part of thefinal product, it is likely to have beenused in the industrial process thatcreated the product. For example, paperis manufactured from wood that iswashed and soaked in vats of water andchemicals to form pulp. The pulp isrinsed, squeezed dry and then pressedinto paper (Prentice Hall 2000). Manyindustries, such as power plants andsteel mills, use high volumes of water tocool down hot machinery.

Worldwide household use is a thirdleading use of water. Most of us takesafe, plentiful water for granted, but inmany parts of the world women andchildren still spend hours every daywalking to shallow wells, collectingwater in jugs and carrying it home.

Most people in Florida and in otherparts of the United States get their waterfrom public-supply systems. When youhave hundreds of people living in asquare kilometer, it is much moreefficient and safer to have the county orcity water department deliver water tohouseholds than to have eachhousehold drill its own well or build itsown water tank. Public water systemssupply water to schools, businesses andindustries, as well as to homes.

In the past century, populationgrowth, industrial development

and expansion of irrigated agriculture haveresulted in an enormous increase in theamount of water used throughout theworld. Throughout the first 75 years of thetwentieth century, absolute and per capitademand for water throughout the world

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increased. Beginning in the mid-1980sand early 1990s, however, these trendsreversed in the United States and wateruse began to decrease despite continuedincreases in population and economicwealth. Between 1980 and 1995, wateruse in the United States declined bynearly 10 percent. The two largestcomponents of United States water use— thermoelectric cooling andagricultural irrigation — declined byabout 10 percent. Industrial use droppedeven more than thermoelectric coolingand agriculture (40 percent), asindustrial water use efficiency improvedand as the mix of United States industrychanged. Part of the decline inagricultural use is a consequence of theavailability of more efficient methods ofirrigation. Drip irrigation is a processwhereby water is applied directly to theroots. It was first developed in Israel andhas expanded worldwide.

FLORIDA WATER USEFLORIDA WATER USEFLORIDA WATER USEFLORIDA WATER USEFLORIDA WATER USEAND TRENDSAND TRENDSAND TRENDSAND TRENDSAND TRENDS

In 1995, ground water accounted for 60percent of the water withdrawn in Florida.Nearly 93 percent of the state’s populationrelied on ground water for their drinkingwater needs, far more than any other state inthe nation (Solley et al. 1998). The majority ofground water is withdrawn from the Floridanaquifer, although the Biscayne aquifer is theprimary source of potable water in southFlorida and the sand and gravel aquifer is themain source of potable water in portions ofwest Florida. Groundwater withdrawalssteadily increased between 1950 and 1990,but decreased 7 percent between 1990 and1995, even though the populationincreased 9 percent, from 12.94 to 14.15million. Following trends in the UnitedStates as a whole, use of water foragricultural irrigation, industry andthermoelectric cooling has also decreased inFlorida, due to more efficient use.

Total surface water use: 2,881 mgd

Total groundwater use: 4,336 mgd

Florida Freshwater Use1995

Surface Water

Ground Water

Source: Marella 1999

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Statewide per capita residential use ofwater has decreased from an average of 144gallons per day in 1980 to 103 gallons perday in 1995. This decrease has resulted fromconservation efforts, including the use ofmore efficient toilets and showers, use ofreclaimed water for lawn irrigation, and useof water-saving landscape techniques(Marella 1999). Florida households still useone-half of their water for landscapeirrigation.

Florida ranks low (30th in the nation) inwithdrawals of fresh surface water. Between1990 and 1995, withdrawals of surface

Freshwater Withdrawals

water increased by less than 1 percent. Theprimary uses of fresh surface water are foragricultural irrigation and as cooling waterfor power plants. Major sources of freshsurface water for irrigation are LakeOkeechobeee, Lake Apopka, theCaloosahatchee River and the marshlandsassociated with the headwaters of the St.Johns River. In some parts of the state,surface water is a significant component ofpublic supply. Hillsborough River and theTampa Bypass Canal supply HillsboroughCounty, and Deer Point Lake Reservoirsupplies Bay County.

Water ReuseWater ReuseWater ReuseWater ReuseWater Reuse

Florida has become a leader amongstates in the reuse of water. Every day, 60gallons of wastewater for each person flowsout of homes and into sewers. As thiswastewater travels miles through the collection system, it is diluted by ground

water that infiltrates joints and defects

in the sewers. By the time wastewaterreaches the treatment facility, its volumehas increased to about 100 gallons perperson per day. Wastewater is now about99.9 percent water and 0.1 percentpollutants. After treatment, wastewater canbe safely used for many purposes.

Source: Marella 1999

81

State law requires reuse within waterresource caution areas. In 1999, the totalcapacity of all reuse systems in Florida wasabout 1.04 billion gallons per day, nearlyhalf of the total permitted capacity of alldomestic wastewater treatment facilities inthe state. A total of 523 million gallons perday of reclaimed water was reused in 1999.

Reclaimed water is being used forlandscape irrigation (including golf

courses, parks, highway medians,playgrounds and residential properties),agricultural irrigation (including irrigationof edible crops), aesthetic uses (decorativeponds, pools and fountains), groundwaterrecharge, industrial uses (for cooling,process or wash waters), wetlandscreation, restoration and enhancementand fire protection (use in hydrants andsprinklers).

Good quality water in adequateamounts is indispensable for the water wedrink, but it is also essential for many otheruses. We cannot safely swim or fish inpolluted waters nor can Florida’s naturalsystems survive without adequate water ofgood quality.

The recreational and ecological valuesof good quality water and other naturalresources are frequently acknowledged butare rarely considered in managementdecisions because we don’t buy and sellthem as we do other commodities. Anarticle published in 1997 (Costanza et al.)in the journal Nature summarizes andsynthesizes studies aimed at estimating thevalue of ecological functions and services.The authors conclude that the economicvalue of Earth’s natural systems averages$33 trillion per year, which is 1.2 times asmuch economic value created by humansand measured by the combined grossnational product of all the countries in theworld.

Scientists use a number of tests andmeasures to help them determine waterquality. These include turbidity, nutrientlevels, pH, dissolved oxygen, conductivityand temperature.

Turbidity is characterized by a cloudyor muddy appearance caused bysuspended solids that decrease the abilityof the sunlight to penetrate the water. Themost common suspended solids are soilparticles and algae. Water may sometimesbe naturally turbid because of highamounts of organic debris, erosion, or

waves or floods that suspend sediments.High turbidity reduces underwater

plant growth by limiting sunlightpenetration and photosynthesis. Adecrease in plant growth results in adecrease in the number of organisms thatdepend on plants for food and shelter. Soilparticles also affect the health of fish byclogging and irritating their gills. Turbidwaters may suffocate some aquatic plantsand animals and impair reproduction anddevelopment of eggs and larvae.

Nutrients in the proper amount arenecessary for healthy aquatic systems, butin excess, nutrients, primarily nitrogen andphosphorus, can be harmful. Nutrientscome from runoff containing fertilizer,waste from leaking septic tanks, decayinglawn debris and animal wastes. When toomany nutrients are present, certain plantsgrow explosively and crowd out otherplants, creating a monoculture. Increasesin nutrients may result in algal blooms inlakes and rivers. When algae multipliesrapidly, it uses up dissolved oxygen, leavingless available for other forms of aquaticlife. Excess nutrients also frequentlyincrease nonnative nuisance plants, suchas water hyacinth and hydrilla.

The measure of the amount ofhydrogen ions (H+) and hydroxide ions(OH-) in a solution is pH (potential ofhydrogen). The more acidic a solution, thegreater the amount of hydrogen ions. Themore basic or alkaline the solution, thegreater the amount of hydroxide ions.The pH scale ranges from 0 to 14.

Water QualityWater QualityWater QualityWater QualityWater Quality

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The lower the pH, the more acidic thesolution is; the higher the pH, the morebasic the solution is. A solution with a pHof 7 is neutral, neither basic nor acidic.Pure water has a pH of 7. Orange juice hasa pH of 4 and battery acid has a pH of 0.5.Milk of Magnesia has a pH of 10 and lyehas a pH of 14. Most aquatic organismsprefer water with a pH ranging from 6.5 to8.5. As acidity rises (pH falls), othercompounds in contact with the water orthe soil may release toxic elements (forexample, aluminum and mercury).Stormwater runoff containing leakagefrom faulty sewer lines or septic tanks,runoff from agricultural areas and acidrain can all decrease pH in lakes, rivers andestuaries, threatening aquatic organismsand releasing potentially harmfulelements.

Dissolved oxygen in water is essentialfor the survival of nearly all aquatic plantsand animals. Aquatic organisms, includingmost fish, generally thrive when dissolvedoxygen levels are 5 parts per million (ppm)or greater. Oxygen in the water comes fromthe air and as a byproduct ofphotosynthesis. The cooler the water, themore dissolved oxygen it will hold.However, at night when photosynthesisstops, animals continue to use oxygen andthe dissolved oxygen content of waterdrops.

Conductivity refers to how well thewater conducts or transmits an electricalcurrent. Pure distilled water does notconduct a current. As the concentration ofminerals and salts in the water increases,however, conductivity rises. Conductivityis therefore an indirect measure of themineral content of water. Sediments fromstormwater runoff and intrusion ofseawater increase the mineral content ofwater. Increases in conductivity mayindicate water quality problems fromincreased salinity or increased sediment.Both of these make water less useful tohumans and to natural systems.

Temperature affects the growth and life cycles of many aquatic organisms.

Nearly all organisms have a temperaturerange they prefer or even require.Sediments can absorb heat and increasewater temperature. Stormwater runofffrom heated impervious surfaces andpower plant outfalls also increases watertemperature. As water temperatureincreases, the life cycles of aquatic insectsmay accelerate. The growth of algaegenerally increases, whereas the growth ofother plants such as aquatic grasses maydecrease. Other aquatic organisms maybecome more sensitive and vulnerable todisease and their reproductive cycles maybe disrupted with increased temperatures.

CAUSES AND SOURCES OFCAUSES AND SOURCES OFCAUSES AND SOURCES OFCAUSES AND SOURCES OFCAUSES AND SOURCES OFWATER POLLUTIONWATER POLLUTIONWATER POLLUTIONWATER POLLUTIONWATER POLLUTION

Although pollution is often defined ascontamination by harmful chemicals orwaste materials, environmental pollutioncan be anything that harms or causes animbalance in plants and animals in theirnatural habitat — even though thesubstance may not be harmful to humans.For example, phosphorus and nitrogen arecommon elements of most fertilizers. Theyare not harmful to humans. However,nitrogen runoff can be a pollutant insaltwater bays and estuaries, such asTampa Bay and the Indian River Lagoon,and phosphorus runoff can be a pollutantin freshwater habitats such as theEverglades and Lake Apopka and otherfreshwater lakes because it causes animbalance in the natural system.

Pollution is usually caused by humanactivities. Pollutants aren’t alwaysdetectable by smell, sight or taste. Watermay look and smell clean and even tastefine, but it may still be contaminated andunsafe for drinking.

Despite successes in cleaning up somewater pollution, many modern pollutantsare very difficult to remove, and it isobviously better not to pollute in the firstplace. Heavy metals and syntheticchemicals pose particular hazards tohumans and other forms of life.

Heavy metals, such as lead and mercury,

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can interfere with production ofhormones and with reproduction. Leadcan further result in physical and mentaldevelopmental problems in children.Other metals, such as copper and zinc, areless dangerous to humans but are toxic toaquatic life (Stauffer 1998).

More than 10 million chemicals aremanufactured today. Most are used inagriculture and industry. Some breakdown quickly, whereas others, like heavymetals, remain in the environment fordecades. Fewer than 2 percent of thesechemicals have been fully tested withregard to human health risks, and nohealth information is available for morethan 70 percent of them (Stauffer 1998).

Water may be polluted in two generalways: by point source pollution and bynon-point source pollution. With pointsource pollution, the cause of the problemcan be traced to a single source, forexample, a pipe discharging waste from afactory. Non-point source pollution ismore diffuse and originates from diversesources over a wider area.

In the past, pollution from industrialand domestic point sources was common.Stronger regulations, new technologiesand more advanced treatment of wasteshave reduced point source pollution.Today most water quality problems resultfrom non-point source pollution,including stormwater runoff, septic tanks,runoff from croplands, dairies, feedlotsand farms, and erosion from constructionsites and unpaved roads. Non-pointsource pollution carries pesticides andfertilizers from lawns and fields, oil andgreases from roads and parking lots,sediments from construction sites andclear-cutting of trees, and wastes fromimproperly functioning septic tanks.

In 1982, the state of Floridaimplemented a rule to reduce stormwaterrunoff. Since 1982, all new developmentshave been required to use bestmanagement practices (BMPs) tominimize runoff during construction and

to treat stormwater after construction.These BMPs include requiring swales,retention ponds, detention ponds anddetention ponds with filtration.

FLORIDA WATER QUALITYFLORIDA WATER QUALITYFLORIDA WATER QUALITYFLORIDA WATER QUALITYFLORIDA WATER QUALITYAND TRENDSAND TRENDSAND TRENDSAND TRENDSAND TRENDS

Because Florida is so populous andhas grown so rapidly, an important sourceof pollution, particularly of surface water,is urban storm water. Surface waterquality problems occur with the greatestfrequency in heavily populated areas —the southeast, in the central region nearOrlando, in the St. Johns River basinparticularly around Jacksonville, inPensacola Bay and its tributaries, in thePeace River basin and along the westcoast between Tampa and Naples. Waterbodies whose watersheds include largeurban areas and intensive industry andagriculture have the poorest water quality.

Developed areas have a much higherproportion of impervious surface thanrural areas. Impervious surfaces arecovered with buildings or asphalt,concrete and other materials that preventwater from seeping into the ground. As aconsequence, the volume of storm waterincreases, carrying pollutants with it.

The Florida Department ofEnvironmental Protection monitors waterquality in over 600 surface water bodiesthroughout the state. Between 1986 and1995, the water quality in 71 percent ofthese water bodies was unchanged, thewater quality of 20 percent improved, andthe water quality of 9 percent declined. Ingeneral, improvements were related tobetter control of point source pollution,particularly discharges from wastewatertreatment plants. Declines in waterquality generally resulted from increasesin stormwater runoff.

Florida’s ground water, as well as itssurface water, is vulnerable tocontamination. Large portions of the stateare covered with well-drained sandy soilsoverlying porous limestone. High

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The Effect of Covered Surfaces on Runoff

amounts of rainfall contribute to thepotential for contamination of groundwater: in many places, anything on thesurface is likely to percolate through to theground water. Connection betweenground water and surface water alsomeans that anything found in surfacewater is likely to find its way into groundwater and vice versa.

In the 1980s, hundreds of wells inFlorida were found to be contaminatedwith the soil fumigant ethylene dibromide(EDB). Other wells were found to becontaminated with dry-cleaning solventand gasoline from leaking underground

storage tanks. This resulted in

standards for water well construction andwater testing within areas of knowngroundwater contamination. Groundwater in Florida has also been found tobe contaminated with nitrate fromfertilizers or leachate from septic tanks.Nitrate contamination of ground watermay cause “blue baby syndrome,” acondition affecting human infants under6 months of age. High levels of nitratesdecrease the amount of oxygen carried inthe baby’s blood. The skin around theeyes, mouth and feet appear blue. Thesyndrome may also cause difficultybreathing, loss of consciousness,convulsions and even death.

Source: Fernald and Purdum 1998

85

Monitored Surface Water Quality Trends1986–1995

ConclusionConclusionConclusionConclusionConclusion

not just in Florida but throughout theworld.

“In most countries, water is priced atonly a fraction of its real cost. The workingassumption is that it’s an unlimited publicresource, and the result is that fewconsumers have any incentive to use itsparingly. Yet the time is coming whenwater must be treated as [a] valuable[resource], like oil, not free, like air”(Voyage Publishing 1996).

Although the analysis of water qualityand water pollution is complex, the needfor adequate amounts of clean water isclear. Some major water quality problemsof the past, particularly waterborneepidemics, are now well controlled. Wemust face new challenges resulting from afast-growing population, industry andintensive agriculture.

As water becomes scarcer, it willundoubtedly become more expensive,

Source: Fernald and Purdum 1998