TITLE Level. INSTITUTION - Education Resources Information ...

DOCUMENT RESUME

ED 361 170 SE 053 506

TITLE Project Water Science. General Science High SchoolLevel.

INSTITUTION Water Education Foundation, Sacramento, CA.SPONS AGENCY California; California State Dept. of Water

Resources, Sacramento. Office of WaterConservation.

PUB DATE 91

NOTE 56p.; Accompanying materials include the WaterEducation Foundation's "Layperson's Guide to DrinkingWater," a sliding chart of water facts, and aCalifornia Water Map. The sliding chart andCalifornia Water Map are not reproducible.

AVAILABLE FROM Water Education Foundation, 717 K Street, Suite 517,Sacramento, CA 95814.

PUB TYPE Guides Classroom Use Teaching Guides (ForTeacher) (052)

EDRS PRICE MF01/PC03 Plus Postage.DFSCRIPTORS Conservation (Environment); *Ecology; *Environmental

Education; High Schools; Poisons; Science Activities;Science Education; *Science Experiments; ScienceProjects; Secondary School Science; *Water Quality;*Water Resources; Water Treatment

IDENTIFIERS *California; *Hands On Experience; Hands on Science;Precipitation

ABSTRACTThis teacher's guide presents 12 hands-on laboratory

activities for high school science classes that cover theenvironmental issue of water resources in California. The activitiesare separated into three sections. Five activities in the section onwater quality address the topics of groundwater, water hardness,bottled water, water purity, and water purification. Four activitiesin the section on water and the environment address the topics ofwater clarity; rainfall, geography, and vegetation patterns inCalifornia; toxins in water; and water ecosystems. Three activitiesin the section on water and people address the topics of waterdistribution, water conservation, and water treatment. The guidecontains a glossary of 34 terms. The attached "Layperson's Guide toDrinking Water" explains some of the major concerns and controversialissues about today's drinking water and the kind of decisions thatneed to be made. It also contains a sliding chart of water facts, anda California Water Map. (MDH)

***********************************************************************

Reproductions supplied by EDRS are the best that can be madeIc from the original document.***********************************************************************

PROJECT

WATER

SCIENCE

General ScienceHigh School Level

0

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"PERMISSION TO REPRODUCE THISMATERIAL HAS BEEN GRANTED BY

Valerie Holcomb

TO THE EDUCATIONAL RESOURCESINFORMATION CENTER (ERIC)

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; II I I I; II

U DEPARTMENT OF EDUCATIONOfIce o Educahonal Research end ImprovementEDUCATIONAL RESOURCES INFORMATION

CENTER (ERIC)

Whoa dOcument has been te/OrOduCed ustriciyiki from Int prOn Or organizationongunahng it

o Minor changes have been made lo IrtiprOvereproduction Quality

PoinIs 01 view Or opinions slatO in this clOCu-ment do nOt neCeStardy officiMOERI pOsilson Or policy

BEST COPY AVAILABLE

Project Water ScienceSecondary Environmental Science

Teacher's IntroductionProject Water Science is intended for use in earth and physicalscience classes. It gives secondary science teachers a series ofhands-on exercises organized to cover one of the most importantissues of our timeswater, and its importance to our environmentand our lives.

Consistent with the new Science Framework, this material is orga-nized thematically and cuts across all areas of science. These labsca a be used as a unit or integrated into an existing water unit.Ail student pages may be photocopied.

Teacher's information for each of the three sections appearson the blue pages.

Project Water &lanais divided inW three sectionsWater Quality,Water and the Environment, andWater and People.

Materials accompanying Project Water ScienceCalifornia Water MapLayperson' s Guide to Drinking WaterWater Trivia Facts CardWater Education Foundation brochure and order formEvaluation form

OptionalVideoWaterquest

Teacher and Student guides are published by the Water Education Foundation.The guides were jointly funded by the Foundation, the California Department ofWater Resources and the California Department of Education, Environmental/Energy Education Grant Program. Additional educational materials are availablefrom the Water Education Foundation, 717 K Street, Suite 517, Sacramento, CA

94814, 916-444-6240

EditorRita Schmidt Sudman

WriterJudith Wheadey

Editorial AssistanceNlerle FraserValerie Holcomb

Photos

L.S. Bureau of ReclamationRita Schmidt Sudman

DesignRebecca Sobine

The mission of the Water EducationFoundation, an unbiased. nonprofitorganization. is to develop and irnple-ment education programs leading to abroader understanding of water issuesand to resolution of water problems.

A Look InsideWater Quality page

Teacher's Information. Labs 1-5 4

Lab I How Low Can You Go'? 6Groundwater and Porosity

Lab 2 To Suds or Not To Suds 7Water Hardness

Lab 3 How Does It Taste? 8

Is Bottled Better?

Lab 4 Pure As The Driven Snow'' 10Parts per Million or BillionWater Quality in Drinking Water

Lab 5 Water. Water Everywhere But Not A Drop To Drink . .12How to Build a Solar Water Purifier

Water and the Environment

Teacher's Information. Labs 6-9 13

Lab 6 Surveyine a Watery Biome 17

Water TemperatureWater Clarity

Lab 7 It Never Rains in Sunny CalifornaRainfall, Geography, and Vegetation patterns

Lab 8 This Game May be Hazardous to Your Health 14Accumulation of Toxins in the Foodweb

1

Lab 9 It's a Small World After AllA Water Mini-Ecosystem

Water and People

Teacher's Information. Labs 10-12

Lab 10 Where Does All the Water Go'?Distribution in California

5

/ 2

Lab 11 I Can Make a Difference! 31

Lab 12 The Mud Mystery. . ."I Can See Clearly Now- 33 .4targik.A Water Treatment Inquiry

Water Conservation

Glossary 14

4

ii-

SECTION

Ii

4

Water QualityTeacher's Information Labs 1-5

LAB 1

HOW LOW CAN YOU GO?

Grow:limier and Porosity

Obisc DyeStudents will become aware ofsome of the pressing issuesinvolving contamination of ourlimited surface and groundwatersupplies.

Demonstration materials needed1. large glass bowl, jar or

fish tank2. glass beads, fish tank

rocks or sand3. food coloring

Lab HintsUse pea-sizegravel, fine sand,and soil typical inyour area.

filling the crevices. Using astraw to simulate a well,siphon out water (or useaspirator) and note the waterlevel on the side of glassbowl, jar or fish tank with agrease pencil. A cone ofdepression should be formedif particles are small enoughand extraction is largeenough.

Extension ActivitySuggest that some of the groups

change the proportion of sandto gravel to soil. Discusshow the pore size maychange with the mixture.Ask what would happen ifthe gravel was angular asopposed to round.

Activity1. Introduce this learning unit

with the Reading and byreferring to recent newsarticles regarding waterquality problems. Ask thestudents if they are aware ofany pressing local waterquality issues.

2. Hand out photocopies of theLayperson' s Guide to Drink-ing Water p. 2. Promotediscussion about the issues.

3. Using a glass bowl, a largejar or fish tank, simulate aground water basin by addingsand, or gravel and fish tankrocks or another medium likeglass beads. By adding ameasured amount of water,students can observe re-charge. withd:awal and water

Ppoject Water Science

LAB 2TO SUDS OH NOT TO SUDS

Water Hardness

ObjectiveStudents will evaluate the hard-ness of tap water and recognizehardness as an important factorin water quality.

Lab HintsSmall jars like baby food bottlesmay be used if test tubes are notavailable. Use liquid soap, notdetergent. For themystery sample, adda handful of Epsomsalts to a liter oftap water.Epsom saltscontain mag-nesium, andwiP mrle thesample agood exampleof hard water.

Extension ActivitiesSee if students can design an-other lab to test hardness. Thiscould be washing an oily rag indifferent types of water. Alsosuggest one group use detergentfor the initial experiment. Dis-cuss how water softeners work.Show the build up of scale in atea kettle or hot water pipe.Invite a local plumber in to talkabout scale and water softeners.

LAB 3HOW DOES IT TASTE?

Is Bottled Better?

ObjectiveStudents will recog-nize taste as a criterionof water quality

&MNHave students readpp. 12-13 inLayperson's Guide toDrinking Water.These pages maybe photocopied.

Lab HintsCollect water from varioussources (tap, distilled, bottledspring, carbonated, etc.) and putinto plain bottles labeled with anumber. Have unsalted sodacrackers available to eat be-tween samples to remove tastesfrom mouth.

Extension ActivityHave students test water

samples for hardness. Re-late mineral content to taste.

Water Education Foundation

tAB 4PURE AS THE OWEN SNOW?Water Quality in Drinidng Water

ObjectiveStudent willmeasure twoindicators ofwater quality,pH and chlorinelevel, and be ableto identify theirimportance inevaluatingdrinking water.

of testing pH, like litmus paper,may be substituted.

Extension ActivityHave students allowwater samples in partA to evaporate to seeif food coloring resi-due reappears. Have alocal water districtofficial come talk tothe class about localwater treatment pro-cesses. Ask about thelocal THM levels.Possible researchproject: What are the

newest advancements in watertreatment?

ReadingHave students read pp. 8-11 inLayperson' s Guide to DrinkingWater. These pages may bephotocopied.

Lab HintsPart A: Remind students thatfood coloring is already dilutedat 1 part coloring to 10 partswater. Put white paper underclear containers so students canobserve the color changes. Ifyou don't have enough clearcontainers, white plastic eggcartons may be used.

Part B: Use the same watersamples as in Lab 43, How DoesIt Taste? This will give thestudents opportunity to discussthe relationship of water qualityto taste. Use any pool or spatest kit that contains OTO,orthotolidine, for testing chlo-rine, and phenol red for testingpH. You may want to reviewthe concepts of pH, acidity, andalkalinity with the class. If youhave limited pool test kits, youcan have half the class work onpart A, while the other haifworks on part B. Other methods

LAB 5IVAIBI, WATER EVERYWHERE,BUT Mil A DROP TO DRIM(..."How to Build a Solar WaterPurer

ObjectiveStudents will build a waterpurifier using the principles ofthe hydrologic cycle. Studentswill recognize the finite natureof water as a resource.

Pre-Lab activityReview the hydrologic cyclewith the students. Boil water,condense steam on a cold plasticcup. Using a lamp, melt an icecube, and then allow the waterto evaporate.

lab HintsStudents can bring intheir own buckets orcoffee cans and buildindividual stills orwork in groups.Use plastic or glasscontainers if beakers areunavailable. Use lightcolored or clear weighton the plastic wrap.(Dark weight will absorb heatand can bum through wrap.)

Extension ActivitiesHave some of the group putother materials beside salt intheir water (e.g. food coloring,lemon juice, sugar, etc.)

Use Trivia Game to discuss theamount of fresh and salt waterin the world.

Assign a research project on theYuma. Arizona desalinationplant or the Santa Barbaradesalination plant.

Contact a branch of the U.S.Navy and ask how large ships,such as aircraft carriers provideenough fresh water for theircrews.

Discuss other saline waterproblems: salt water intrusionin coastal areas, agriculturaldrainage problems like those atKesterson Reservoir, ColoradoRiver water and agriculturaldrainage.

Water Education Project Water Science 5

1

0

How Low Can You Go?Groundwater and Porosity

introductionWater falling on theground either runs offthe surface, or soaks

into the ground. The amount ofwater that can be absorbed into

the ground, and how far I Resultsdown it travels, is

dependent On the sizeand shape of theparticles. The w ater

molecules move intothe spaces. or pores.between the particles.

Hypothesis

QuestionWhich kind of medium can holdthe most water?

Materialssandgravelgarden soil4 glass or clear plastic

containers/groupgraduated cylinderwater

,

ProcedureFill the containers with ,,and.gravel, garden soil, and anequal mixture of these threesubstances. Shake the con-tainers to distribute the con-tents. Label each one.

2. Add water from a graduatedcylinder to each container.Pour slowly. Measure howmuch water each containerwill hold before overflowing.

3. Record your results in the 1, Conclusiontable.

I. Which medium absorbed themost water?

Data

sand

gravel

solid

mixture

ml

ml

nil

ml

'. Which medium absorbel the least water?

3. What does this mean about the pore space in each container?

4. In a rainstorm. which medium would have the heaviest runoff?

Project Water Science dater Education Foundation

To Suds OP Not To SudsWater Hardness

Introductionne of the characteristics 01water quality is its hard-ness. which refers to the

amount of minerals dissolved init. These minerals includecalcium and magnesium. Hard Resultswater has many dissolved min-erals. which interfere with itsusefulness in washing. Theminerals react with soap to formscum instead of suds. Theseminerals can also form a depositcalled scale inside boilers andhot-water pipes.

Hypothesis

QuestionHow hard is our tap water?

Materia'stest tubessoap solution (not detergent )glass markers or crayonswater solutions: distilled.

tap, bottled spring, saltmystery water sample

Procedure. Pour 5 ml. of distilled water

into a test wbe. Add 1 dropof liquid soap solution, covertube with thumb. and shake.Continue adding drops ofsoap solution until ou havelasting suds. Shake vigor-ously atter each drop.

'se this as a control.

2. Repeat procedure with otherwater samples. I. se a clean.labelled test tube for eachsample. Record the numberot drops ol soap solutionnecessary to producelastini2 suds.

Data

Is your tap water hard orsoft? distilled water ; drops

tap water ! drops

2. Which was the hardestwater?

Which was the softest?

bottled sprim: ater drops

salt water drops

mystery water sample i drops

: 3. Was there any cloudiness in any of the water samples afteradding soap? What do you think this is? !

4. Which would he better for washing_ clothes. distilledwater or salt water? Why?

Conclusion


L A B

2

Project Water Science 7

8

How Does It Taste?Is Bottled Better?

IntroductionThe bottled water industry isbooming, but is bottledwater really "better" than

tap water'?

According to the industry.more than $2 billion inbottled water was sold in the'United States in 1989. doublethat of five years before.California leads all otherstates in bottled water con-sumption and accounts foralmost half of the bottledwater consumed in the nation.One out of three Californiahomes uses bottled waterdouble the national average.

Do Californians drink bottledwater for safety or taste'? Thereasons behind this boom arehard to pin down or quantify.Some consumers buy bottledwater because they believe itstaste is superior to tap water's.

The expensive, imported brands,too. have a definite "snob ap-peal"particularly when servedup with a twist of lime. In this,the era of physical fitness andwell-being, there is also an

allure to the "natural-ness" touted by somebrands. The safety of tapwater is a concern. asmore refined analyticaltechniques make itpossible to detect smallerand smaller amounts of

various contaminantswith little conclusive

evidence of their long-termhealth effects.

a

But just as tap waters vary fromregion to region. so do bottledwaters vary, both in type andquality. In California. watersold as "mineral water" laustcontain more than 500 milli-

grams per liter of dissolvedmineralsfar more than

most tap waters.

Project Water Science

Of course. any waterexcept distilled istechnically a "min-eral" water. Sincewater is a solvent,it naturally picksup an assortmentof minerals and

other substances on its trip'Lliiough the hyirologic cycle.(The substances found in waterare measured in milligrams perliter or in parts per million.equivalent terms. One milli-gram per liter is equal toone milligram of thesubstance dissolved ina liter of water.)"Sparkling water" iscarbonated, eithernaturally or artifi-cially, with dis-solved carbondioxide gas, while"still water" (tapwater and many waters sold asdrinking water) comes minusthe bubbles.

Testing the WatersIs bottled water necessarily"better"? From a taste perspec-tive alone. there are those whowould argue this point, espe-cially if the waters in questionarc all placed on equal foot-ingchilled and tasted in a"blind" test under controlledconditions.

A news segment on Los Ange-les television station KNXTfeatured a blind taste compari-son of bottled water and the tapw-ter the Los Angeles Depart-meta of Water and Power servesits customers in Hollywood.The tasters rated the tap wateramong the best, according to thenewscast.

If the label reads "drinkingwater," chances are it is tap orwell water which may haveundergone additional filtering orprocessing prior to bottling. Bylaw, "spring water" must comefrom a spring (unless the"spring" is just in the com-pany's name): it may or may nothave had extra processing.


Another taste test, this oneconducted for the SanFrancisco Chronicle by apanel of food and waterquality experts, rated BayArea water samples. Inaddition to the tap waters

tested was an expensivebottled water from France

which finished at the bottom,behind the tap waters. Across

the continent. Consumers Unionstacked 23 sparkling waters. 14still bottled waters and one tapwater against each other. Ac-cording to these experts, thebest tasting water was NewYork City tap water.

Health and SafetyWhat about the health andsafety questions'?"If everything's workingproperly, tap water andbottled water should heequally safe," says Dr.Jack Sheneman of theCalifornia Department ofHealth Services' Food andDrug Branch. the divisionwhich oversees the bottledwater industry.

To make sure things keepon "working properly."purveyors of tap water andof bottled water both arc re-quired to meet quality regula-tions set by federal and stategovernments and must regularlyreport chemical, physical andmicrobiological test results tothe state.

Bottled Water Test: Hard vsSott Water

Overall, most of the bottledwaters contain lower levels

of dissolved minerals.Minerals, though. helpmake water palatable.and some water bottlersremove and then addback minerals to theirproduct to improve itstaste. Distilled water,which contains no dis-solved minerals. is flat-tasting and not at allrefreshing.

".

Underground contaminationsuch as by improperly used,stored or disposed of chemi-calscould as likely affectbottled waters drawn fromsprings or wells as public sup-plies. The additional processingsome bottled waters undergo.howevei, could remove some ofthese substances.

Two minerals, magnesium andcalcium, contribute to a water's"hardness." Many of the bottleddrinking waters in the varioustests were considered "soft" (thepoint separating harder fromsofter is son" 'where in theneighborhoc..! of 70 milligramsper liter of hardness). whilesome of the state's tap watersparticularly those in southernCalitbrniaare on the hardside.

Although it has not been provenconclusively, some health ex-pens believe harder water isbetter for cardiovascular (heart)health than soft. One specula-tion offered is that hard waterhas some sort of "protective"quality that helps preventcardiovascular disease.

QuestionsI. What kind of water do peoplein your class prefer?

2. What was the least popularwater'? State reasOns.

Water Sample HatingSample Your Rating Score Class Average

Rating Score

I

1

3

-I-

5

J

Water Education Foundation Project Water Science 9

LAB

41Pure as the Driven Snow?Parts per Million OP Billion

introductionSubstances dissolved in,water are usually mea !sured in parts per million

or parts per billion. Rut howdiluted is that? In this part ofthe lab, you will create solu-tions that are one part permillion and one part per billiondilutions.

Different toxins or poisons areconsidered ha/ardous at differ-ent concentrations. Accordingto the Environmental ProtectionAgency (EPA). the follow ingare maximum contaminationle\ els allowed for drinkingwater in parts per hilhon ( ppb):Arsenic 50Selenium 10

Nitrates 10,000Trihalomethanes ) 10)

Materials9 clear containers or one

white plastic egg cartonwhite papertooth picksfood coloring

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.4111141m

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10 Project Water Science

ProcedurePut down sheets of whitepaper. Line up nine clearcontainers. tor use whiteplastic egg cartons).Label #1-9.

2. Put 10 drops of food coloringin #1. Food coloring isalready at a dilution of 1:10.

3. Take one drop trom #1 andplace it in container #2.Add 9 drops water w ith aclean dropper and mix witha toothpick.

4. Repeat this process in eachcontainer. texampk.: 'Fakeone drop from #2. put in #3.add (4 drops water. stir.)Fach dilution will he 10times more dilute than theprevious one.

Data

Container Dilution

1:10

I 100

3

4

5

7

X

Discussion. Which container was at a dilution of 1 part per million?

1 part per billion!

: 2. In which container could you no longer see thc color'?

3. In the last container. was there any food coloring present'?1 low in ight you prove this'?

Conclusion


Pure as the Driven Snow?Water Quality in Drinking Water

IntroductionDrinking water is tested formany substances to makesure it is safe for humans.

In this lab, you will be measur-ing the level of acidity, or pH,and the level of dissolved chlo-rine. Chlorine is frequentlyused to disinfect, or destroypotentially harmful bacteria,viruses, and other organisms indrinking water. Enough chlo-rine is added to leave residualamount of chlorine in the water,to continue to kill any pathogensin the pipelines that convey thewater to the users.

Materialstap water, or the water

samples from Lab #3pool or spa testing kit

Procedure. Fill both sides of test kit

container with water fromone of the samples. Add 5drops of OTO to the chlorinelest side and 5 drops of phe-nol red to the pH test side.Cap or cover the containersand shake eently to mixcontents.

2. Hold white card or paperbehind container and com-pare color of the liquid withthe indicated colors on thecontainer.

3 Record the chlorine level (thenumbers given are in partsper million (ppm). Recordthe pH level.

4. Repeat procedure with eachwater sample.

Data

Water Sample chlorincppm pH

ResultsI . Which sample had the highest chlorine level?

the lowest? Can you explain this difference?

2. Flow does chlorine level relate to the taste test results from lab#3?

3. What are THMs'?How do they relate to chlorine in drinking water?

4. A neutral pH is 7, which means a sample is neither acidic norbasic. Which of the samples was neutral?Which samples were acidic? Which were basic'?Give a possible explanation as to why they were not neutral.

5. The pH of clean rainwater is between 5 and 6. Give a possibleexplanation as to why rainwater is not neutral.

6. How did the pH of the water samples relate to the taste testresults in lab #3?


Water, Water Everywhere,But Not A Drop To DrinkHow to Build a Solar Water Purifhr

Background Readingusable water also can be created by using solar energy tech-niques. There are desert cities, outside the United States.which receive drinking water from solar evaporators.

Almeria, Spain, a town of 300 people gets all its drinking waterfrom a solar evaporator. Saudi Arabia also uses some solar evapo-rators. Although the process is still impractical, technology is beingdeveloped to allow desert towns and cities to turn water from theocean or other sources of salty water into fresh water. The Califor-nia city of Santa Barbara is planning to.build a desalination plant inresponse to an extended drou2ht.

Plastic

Tape

Weight

Beaker

Salty Water


Results1. How does it taste?

Activity1. Follow the illustration in the

Lab to set up your lab materi-als. The water level shouldbe at least an inch below thetop of the beaker.

2. Be sure that your plasticcompletely covers the top ofthe bucket. The plasticshould sag enough when theweight is placed on it so thata cone shape is formed whichpoints down to the openbeaker. Make sure that theplastic does not touch themouth of the beaker.

3. Place your apparatus in theheat of the sun and leave itthere for a few hours.

4: During class the next day,remove the plastic coveringand taste the water in thebeaker.

Is it fresh or salty?

2. What was the energy source that caused the water to changestates?

3. What are the 3 states of water?

4. How much fresh water is there in the world? (See Water TriviaFacts Card)

5. Why isn't fresh water currently being distilled from ocean waterfor urban use?


Water And The EnvironmentTeacher's Information Labs 6-9

LAB 8

SURVEYING A WATER BIOME

ObjectiveStudents will evaluate twocharacteristics of a fresh waterecosystem: water temperatureand water clarity. Students willdetermine how these character-istics affect living populations.

Lab HintsIf your school is near a freshwater ecosystem, (e.g. pond,stream, lake) you can use thislab as a guide to a field study.If not, you can create your own"pond" by filling a large con-tainer (plastic 5 or 10 gallonpaint buckets work well)with pond water and anassortment of bottomdirt and plants. Ifusing a container,knots on MeyerSampler andSecchi Diskshould be atsmall inter-vals. It is notnecessarythat studentsidentifyplants andanimals by name, but ratherthat they have a generalimpression of the types oforganisms present andtheir relative numbers.

Extension ActivitiesThis lab may be extendedto collecting samples forLab 9: Mini-ecosystems.

LAB 7

IT hEVI31 RAWS IN SU=CALIFORMA

Rohde II, Geography, andVegetation Patterns

ObjectiveStudents will identify rainfallpatterns and relate them togeography, topography andvegetation patterns. Studentswill understand how rainfallpatterns affect water supply inCalifornia.

Lab HintsDivide the class into 6 groups.Assign 10 cities from the Pre-cipitation Chart to each group.Each group will place a coloredsticky dot or pin on the Califor-nia Water Map for the rainfallamount for each city using thefollowing categories:

SE. TION

Red = 5 inches or lessYellow = 6-15 inchesGreen = 16-30 inches

Blue = over 30 inches

Using the same categories, eachgroup will also place a coloreddot on their vegetation profilechart for each of their ten cities.

It would also be a good ideato have a class vegetationprofile with all the citiesindicated. A road map of

California makes findingthe location of the cities

easier.

4


Extension ActivityHave students research howrainfall affects what crops aregrown in California. Irrigationsystems may also be studied.The State's CIMIS (CaliforniaIrrigation Management Informa-tion System) and the use ofhome computers to calculatewater requirements of crops isanother interesting researchtopic.



LAB 8THIS GAME MAY BE HAZARDOUS

TO YOIM HEALTHAccumulation 01 Toxins in TheFoodweb

ObjectiveStudents will understand theconcept of an ecosystem, energytransfer through the aquaticfood chain, and how toxicmaterials can enter the foodchain. Students will appreciatethe delicate balance of nature.

Background informationWater quantity problems haveplagued California since thedays of its early settlers. Ourstate's massive water transporta-tion and storage systems aretestimony to the fact thatCalifornia's water supplies quiteoften do not occur where andwhen they are needed most.Our water supply is sometimes acase of glut or famine, flood ordrought. But all the water in theworldin the right place, at theright timewon't do a drop ofgood if it isn't fit to use.

True, our domestic water sup-plies have come a long waysince the days when a glass ofwater might carry with it thethreat of cholera or typhoid.But almost daily, the newsmedia carry alarming stories oftoxic substances threatening ourgrouRd water supplies. We'velearned that our surface suppliesaren't immune from exotic-sounding contaminants.

The very chemical used todestroy disease-causing bacteriain drinking water has given rise

jWater Education Foundation

to a whole new problemtheformation of substances whichmight possibly cause cancer.The quality of our water sup-plies, once taken largely forgranted, is becoming the focusof increasing concern.

Materials needed1.Layperson' s Guide to Drink-

ing Water. Read pp. 3 and 16.

2."Food"white pipe cleanersand colored pipe cleaners,white and colored paper dots(two-thirds of them white,one third colored)you canget these from the schoolhole-puncher. For a class of30 students you should havea paper bag full of 600 of thewhite food (uncontaminated)and a bag full of 300 of thecolored food (contaminatedwith toxics).

Activity1.Tell the class that this is an

activity about aquatic foodchains. Spend some time inestablishing a definition.NOTE: Do not tell thestudents what the color of thefood represents until after thefish have "fed."

a. Divide the class into threegroups. One group will bethe water daphnia (a smallfreshwater animal) group (18to 20 students). The secondgroup (6 to 8 students) willbe the insect larvae who preyon the daphnia group. Thethird group (2 or 3 students)will be the fish who prey onthe insect larvae.

b. Hand each "daphnia" asmall paper or plastic bag orother container. The bagrepresents its stomach (acontainer to hold food en-ergy).

c. Scatter the "food" (pipecleaners or paper dots) in thearea where the activity isbeing conducted. The areacan be the classroom if thedesks or tables can be movedback, or a grassy area out-side. NOTE: You will haveto establish boundaries.

d. The "daphnia" are nowinstructed to go looking forfood, gathering the "food"and placing it in their con-tainer or bag (stomach). Atthe end of 30 seconds, the"insect larvae" attack the"daphnia" and eat (collecttheir "stomachs") as many aspossible in 30 to 60 seconds.Any daphnia caught mustgive up their "stomach" tothe insect larvae and move tothe sidelines.

e.

f.

The "fish" are now permit-ted to "eat" insect larvae for15 to 30 seconds. The samerules apply. At the end of thetime period, ask all studentsto gather together and bringwhatever food bags they havewith them.

Identify which "animals" arestill alive. The live animalsare to empty their stomach(s)and count ic number ofwhite "foou pieces theyhave and the number ofcolored pieces. List on theboard the species and thenumber of each kind of"food." Hand out data chartsheets.

2.Inform the class that there isa toxic chemical loose in thewater environment. It ispoisonous, accumulates infood chains and stays in theenvironment for a long time.In this activity, all of thecolored pieces of "food"represent the poison. All of

the "daphnia" that were noteaten by the "insect larva"may now be considered deadif they have any colored foodpieces in their food supply.Any "insect larvae" with afood supply that exceeds 50percent of colored foodpieces will also be considereddead. Any "fish" with a highconcentration of the toxicchemical may be able tosurvive, but its ability to wardoff disease, produce off-spring, find and catch foodmay be limited.

3.Discuss the activity with theclass and ask students fortheir observations about howthe food chain works andhow the toxic chemicals canaffect it.

Extension activityResearch: point vs. non-pointpollution, bioaccumulation oftoxins.

Water Education Founiion Project Water Science 15

LAB 8irs A ma WORLD AFTER ALLA Water Mini-Ecosystem

ObjectiveStudents will set up aquaria andstudy variable influences ondaphnia, a small freshwateranimal commonly used as foodfor aquarium fish. Students willrealize how complex an ecosys-tem is to maintain artificiallyand to learn how variables canaffect an ecosystem.

Materials needed1. plankton net or a large jar

2. white porcelain sorting traysor equivalent

3. eye droppers

4. hand lenses

5. light source

6. thermometers

7. 1 to 2 gallon aquaria (or 1gallon jars) with glass tops

8. spring water, filtered pondwater, or tap water which hasbeen treated with antichlorinecompound (purchased in petshop) and allowed to standfor one week. The pH shouldbe about 7.

9. Daphnia magna

ActivityI. Daphnia magna can be pur-

chased from a tropical fishsupply house or collected.

2. If collecting daphnia use thefollowing procedure: Use the


plankton net and jar to collectseveral samples of zooplank-ton by pouring jarfuls ofpond water through the net.Empty the concentratedzooplankton from the smallbottle on the net into a sortingtray. With the eye dropperand a hand lens, select thelargest daphnia (most highschool biology texts havepictures of daphnia) that haveyoung in their brood pouches(seen dorsally and posteriorlyto the eye). Put them in thejar together with water fromthe pond and some materialfrom the pond surface andbottom.

When you have collected anumber of daphnia (several foreach container you intend to setup), take them back to theclassroom and allow them tobecome acclimated to the class-room environment for a day ortwo. You might consider usingaquarium heaters in each ofyour culture containers to main-tain a constant temperature of22°C (72°F).

Once the mini-ecosystems arefunctioning and in balance, youcan have your student teamschange one variable for theirsystem. One or more systemscan be maintained as controls.You may want to assign thevariable change or else let eachteam pick the variable. Theresults of all these changesshould be recorded and com-pared with that of your controlculture. The following aresuggested changes. The stu-dents should observe the daph-nia regarding the effect of the


variable on change of daphniacolor, swimming habits, etc.

1. Aerate the culture

2. Increase or decrease the foodsupply.

3. Increase the hardness of thewater by adding magnesiumand/or calcium salts: slowly,quickly.

4. Increase or decrease the pHby adding 0.1 M acid or baseslowly over a few days orquickly over a few hours

5. Cut off the light source toreduce the DO (dissolvedoxygen) level.

6. Raise or lower the tempera-ture of the culture, slowlythen quickly.

Extension ActivityThere are manyother changes thatcan be investi-gated such ascompetition bythe introductionof another speciesof daphnia or bythe removal of acertain quantity ofdaphnia at regularintervals.

Surveying A Watery BiomeWater Temperature

Background Readingh,, ir temperature deter-

mines, to a large extent.the surface water tempera-

ture. An ordinary thermometercan be used to take the watertemperature, but the readingmust be taken in the shade.(Your hand can provide theshade.)

Temperature plays an importantrole in determining the speciesof organisms which can live in aparticular body of water, andbecause most aquatic organismsare cold blooded, their tempera-tures vary. Although studentswill not be field sampling watertemperatures from ponds andlakes it is important to knowthat water temperature alsoaffects dissolved oxygen levels.

The Meyer Sampler Bottle is thesimplest and least expensivemethod to use for bringing up asample of water so its tempera-ture can be measured.

QuestionHow is water temperature re-lated to depth?

Materials neededI. one thermometer

2. one Meyer Sampler, withcalibrated cord marked inmeters or feet. Instructions tobuild a Meyer Sampler. (seebelow)

ActivityI. Three things are important

when using the thermometer:

a. Shade the thermometer fromthe direct rays of the sun.

b. Immerse the thermometerbulb in the water and let itremain there long enough toallow it to come to the tem-perature of the water sample.

c. Read the thermometer whilethe bulb remains in the water.

2. Measure the surface tem-perature by immersing thetemperature bulb in the water.Record the temperature andlocation.

3. Following your teacher'sdirections, use the MeyerSampler. The Samplershould be lowered with thestopper in place. At theproper depth the cork isopened by a jerk on the cord.Wait a few seconds for thebottle to fill. Record thedepth in your notebook.Carefully haul the bottle tothe surface and insert a ther-mometer. The water tem-perature should be measuredas soon as the bottle isbrought up.

Instructions for making Meyer SamplerObtain a pint or quart bottle which can be tightly corked.

Obtain some strong nylon string and fashion a net around the bottle andattach a fishing weight to the net at the bottom of the bottle.

Connect a cord to the bottle's neck and fasten the cork to it.

You can calibrate the cord by tying single knots in it at foot or meterintervals so you will know at what depth the water sample was obtained.

When the sampler is lowered into the water, it is corked. At the desiredwater depth. the cord is given a sharp tug to dislodge the cork so the watermay flow into the sampler.


4. Repeat Step 3 two moretimes, recording the depth.temperature and numberingyour samples ( 1,2 or 3).

5. Average your temperaturereadings and record them.

6. If you are to take manyreadings over days or weeks.you will be more accurate ifreadings are made at thesame time of day.

Hypothesis

Record

AirTemperature Location

Water TemperatireTrial 1Location Depth .

Trial 2Location Depth

Trial 3Location Depth

ResultsI. Did the water temperature increase or decrease as depth of water

increased?

2. How does water temperature affect the amount of dissolvedoxygen in water? (Hint: which goes flat first, a glass of warm

coke or cold coke?)

3. How might water temperature affect the organisms living it.body of water?

Conclusion

18 Project Water Science Water Education Foundation

Surveying A Watery BiomeWater Clarity

Background ReadingThe presence of different kinds of organisms living in an aquaticecosystem is determined by various aspects of water quality.

It is important to remembez that physical, chemical and biologicalfactors all interact. For example, an overgrowth of algae caused bysewage runoff may cause a severe reduction of dissolved oxygen inthe water, which will threaten the survival of various aquatic ani-mals. It is important to analyze as many aspects of the aquaticenvironment as possible to get a clear view of what is occurring.

The presence of some aquatic plants and animals may not be aclearly reliable indicator of what is happening, because some plantsand animals can grow in polluted. as well as an unpolluted, envi-ronment. However, bioloeical data. along with physical data, arean important part of the total picture.

This Lab will enable you to gain experience in using your senses tolook at an aquatic ecosystem. Some equipment will be used as anextension of your senses. Secchi Disk readines can give an indica-tion of the amount of productivity of living materials in water. Invery productive waters, light penetration will be limited by thepresence of billions of tiny organisms. Clear water is an indicationof low productivity of living organisms.

QuestionHow is water clarity related to productivity of living organisms in afresh water habitat?

Instructions tor making a Secchi DiskThe Secchi Disk is used to determine water clarity by measuring the distance lightpenetrates into the water. The disk is lowered with a line marked off in feet ormeters until it just disappears from sight.

This is known as the Light Compensation Level, the point at which plants will nolonger grow from the bottom of the pond. The conditions for using the disk shouldalways be standardized: clear sky, sun directly overhead, with readings taken in theshade.

The Secchi Disk is a circular plate 20 cm in diameter. It can be made out of 1/4" or3/8" marine grade plywood or 18 gauge metal. The upper surface of the disk isdivided into four equal pie shapes. with each quadrant painted alternately black andwhite with semi-gloss enamel paint. The undersurface is painted black. The centerof the disk is drilled and a weight and eye bolt are attached. A line which has beenaccurately calibrated in meters is attached to the eye bolt.

Water Education foundation Project Water Science 19

Materials needed1. Secchi Disk

2. hand screen, nets, kitchensieve, coffee can and handlens

3. pans to hold collected species

Procedure1. Examine a sample of pond

water. Either observe smallcontainer of water with ahand lens or look at drops ofwater under a microscope.

Record your observations1. Use the Secchi Disk to deter-

mine the limits of visibility inthe water. Lower the Diskuntil it just disappears fromview and record the depth.Lift the Disk and record thedepth at which reappears.The average of the two read-ings is the limit of visibility.Take at least three sets ofreadings and record each ofthem to the nearest 1/4 of ameter. Average your answersbelow.

CO Pre!001 Water Science

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Lower Secchi Disk

1. Depth at which Disk disappears "r?t,

Depth at which Disk appears .,.

Average of two depths

Do this procedure a total of three times

2. Depth at which Disk disappears .

Depth at which Disk appears - ,


3. Depth at which Disk disappears ..

Depth at which Disk appears


4. Average all three answers

questions1. Was the water clear or clr adv?

-. What organisms are present?

3. How organically productive is this water?

Conclusion


It Never Rains In Sunny CaliforniaRainfall, Geography, And Vegetation Patterns

Background ReadingRainfall is controlled by such factors as wind direction, eleva-tion. and temperature. In California, the northern part of thestate receives more rainfall than the southern part of the state.

Since more people live in the south and most of the food is grownin the arid central and southern areas, there is an imbalance. Dis-tributing this water fairly, without harming the environment, is thechallenge of your generation.

Your water supply comes through the hydrologic cycle, in a never-ending process. Water is carried from the ocean by evaporation ofmoisture, forming clouds. As these clouds move through the atmo-sphere. they rise higher. There they are cooled, causing the mois-ture to fall to the land in the form of precipitationdew, rain, hail.sleet or snow. This moisture is either absorbed into the ground.evaporated, or eventually collected in streams and rivers and re-turned back to the ocean where the cycle starts again.

In California, air flowing east meets mountain ranges. is forced upand cools, loses its ability to hold water and therefore rain or snowfalls.

Questions1. Where does precipitation come from?

2. Where are the areas of highest rainfall?

Lowest rainfall?

3. Does elevation influence rainfall?

4. Find two cities or communities that are at or near the sameelevation. How does the rainfall in the two cities differ?

5. How does the amount of rainfall affect streams, lakes, andground water supplies?

6. How does the amount of rainfall affect what plants grow in alocation?


Materials NeedetiI. Water Map (cellophaned or

laminated)

2. California Precipitation Chart

3. Geographic Cross Sections ofCaliforniaVegetation withProfiles

4. Water Soluble markers,adhesive dots, or stick pins

5. Road map of California(optional)

ActivityI. You will be divided into six

teams using materials pro-vided in this Lab. Each teamwill work from a copy of thevegetation profiles and chartof precipitation levels.

2. Each team will be assigned10 cities with their rainfallamounts.

3. Place a colored dot or pin onthe map to indicate theamount of rainfall of eachcity.

Red = 5 inches or lessYellow = 6-15 inchesGreen = 16-30 inches

Blue = over 30 inches

4. Refer to the cross-section map and thenplace a colored dotfor each city onits appropriatelocation on avegetationprofile. Thiswill indicaterainfall amounts relativeto the vegetation profile.


California Precipitation Chart

\ 1 / .1e e e. . . . .I / // /

N N \ \ N N/ 1 / / / 1 // / / / / /\ N 1 N 1 N/ / / / / /N N \ N N N N/ / / / / I/ I / / / / /\ N N N N \ N N/ / / / I /\ N N N N N N N N1 /... N/N.,N,N,N,N,N,N N N1 /

1 / / / / / / I/ / / / / / / / /

N N \ N N N N N N N \ N/ / / / I / / / /\ N/ / / / I / / .1 / 1 /\ N \ \ 1 \/ / / I / / / / /\ N 1 N \ N. /\ \e//\/'/---.1--:=4_ \ / \ /. . . .. . ./ e. . . . . . . ./ / / / / / /N N N N \ N N N/ / I / / / / / /

/ / 1 / / / I / Z / /N \ N N \ N \ N N N N. N

.1 / / / 4.. / / I / / / /N N \ N N 1 N N N N N \N N N N N N N N N \ N

N. \ \ N. N. \1 / / / / /\ \ N \ \ \ \ \ \ \ \/ / / / / 1 / I /

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Average Yearly Precipitation

Station Annual Station Annual

Alpine 16.39 Covina 17.24Altadena 21.19 Culver City 14.09Anza 14.41 Death Valley 2.03Auburn 34.46 Downey 14.38Bakersfield 5.72 Downieville 62.70Beaumont 17.00 El Centro 2.3513erkeley 23.24 Escondido 14.53

Big Sur 40.48 Fort Bragg 39.30Bishop 5.61 Fresno 10.52Blythe 3.75 Garberville 57.09Borrego Desert 5.85 Gasquet Ranger Station 94.22Burbank 15.78 Half Moon Bay 25.22Chico 25.93 Helmet 11.51

Chula Vista 8.67 Idyllwild 25.39Claremont 17.13 King City 11.25Coalinga 7.83 Lakeport 30.04

40" - 89"

10" 39"

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Water Education Foundation 1/4'

Lemon Cove 13.47Long Beach 11.54Los Angeles 14.85Modesto 11.70Monterey 18.35Muir Woods 36.36Needles 4.39Oak land 18.03Oxnard 14.50Palm Springs 5.20Petaluma 24.02Placerville 36.99Redding 40.95Redlands 12.89Sacramento 17.87San Diego 9.32San Francisco 19.71

San Jose 13.86Santa Barbara 17.70Stockton 14.40Torrance 13.13Turlock 11.39Twentynine Palms 3.89Vacaville 24.29Van Nuys 15.99Visalia 9.86Whittier 14.51Yosemite 36.06

Source: California Almanac

Geographic Cross-Sections of California

with Vegetation ProfilesTRINIDAD HEAD - TRINITY ALPS MODOC PLATEAU

Idin.ith Mtn.

TOMALES BAY - COASTAL VALLEYS - CENTRAL VALLEY SIERRA NEVADA

Modi).

iellres pine

PAJARO VALLEY GABILAN RANGE SAN JOAQUIN VALLEY SIERRA NEVADA OWENS VALLEY -WHITE MOUNTAINS

3

pine

iunipef

SAN SIMEON - SALINAS VALLEY SAN JOAQUIN VALLEY - SIERRA NEVADA - OWENS VALLEYDEATH VALLEY

Merra Noah, Rinamini Mins

SAN PEDRO BAY SAN BERNARDINO MOUNTAINS - OLD WOMAN MOUNTAINS - COLORADO RIVER

iilire pine

pinson iuniper

S.in Bernardino \tins

POINT LOMA CUYAMACA MOUNTAINS IMPERIAL VALLEY COLORADO RIVERMires pine

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Water Education Foundation "(;) I Project Water Science 23

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This Game May Be Hazardous To

Your HealthAccumulation of toxins in the foodweb

Data Chart Beginning # Ending # StomachContents

LiveEnd #

Daphnia

Insect Larvae

Fish

QuestionsDescribe the foodweb in this aquatic ecosystem. includinginformation about the proportion of each organism.

2. How did the toxin affect the Daphnia? the larvae'? the fish?

3. What do you predict will happen in this foodweb over time'?

4. How can toxins be removed from an aquatic ecosystem'?

Project Water Science

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Its A Small World After AllWate, Mini-Ecosystem

Background Reading

0ften it is not possible or practical to study an aquatic ecosys-tem (i.e. pond or stream) in the field. On these occasions, it ispossible to create a miniature, aquatic ecosystem in the class-

room. There arc a number of advantages and disadvantages in-volved in doing this. The main thing to remember in this study isthe limitations of application to an actual aquatic environment whendealing with an artificial one.

There are many ways to set up an ecosystem for study. In thisexperiment we will limit ourselves to one species, Daphnia magna.There are a number of reasons for doing this, foremost of which isthe ease of raising and observing Daphna rnagna. In this experi-ment you will study the effects of chaaging ,arious environmentalconditions on daphnia magna.

QuestionHow will variablesenvironment affectof Daphnia magnafleas)?

in aquariuma population(water

,

Materials needed1. plankton net or a large jar

2. white porcelain sorting traysor equivalent

3. eye droppers

4. hand lenses

5. light source

6. thermometers

7. 1 to 2 gallon aquaria (or 1gallon jars) with glass tops

8. spring water, filtered pondwater, or tap water which hasbeen treated with antichlorinecompound (purchased in petshop) and allowed to standfor one week. The pH shouldbe about 7.

9. Daphnia magna


Activity1. Place several mature Daphnia into your team's aquarium (jar)

along with a 1/2 pint (250m1) of pond or stream water rich in

algae and other microorganisms. Repeat this addition of "rich"

pond water every week. Keeping the aquaria well-lighted, to

keep a growing source of algae present. should allow the Daph-

nia population to increase to its maximum in about a week.

Remember to cover the aquaria with glass to pre-,/ent introduc-

tion of unwanted materials and retard evaporat:)::NOTE: If "skin" develops on the water surface. skim it off or

change the water.

2. When all of the cultures are doing well (the population is in-

creasing), they may be considered separate, closed ecosystems.

To determine if the systems are indeed balanced, count the

Daphnia every three days or so over several weeks. This should

give you an approximate idea of when a balanced state has been

reached in each of your cultures when the population level is

steady.

3. Now, what happens to the Daphnia population in each culture

when you change various conditions? The results of the variable

your team will introduce into your aquarium should be recorded

and compared to that of a control culture your teacher will keep.

The following are some of the possible variables:

a. Aerate the culture.

b. Increase or decrease the food supply.

c. Increase the hardness of the water by adding

magnesium and/or calcium salts: slowly, quickly._411011L.

Hypothesis

d. Increase or decrease the pH by adding 0.1 M acid

or base slowly over a few days or quickly over a

few hours. Especially note effects on ptpulation

levels and heartbeat rate. a.: 4e. Cut off the light source to reduce the DO (dissolved

oxygen) level. Note the effect of this change on

Daphnia color, swimming habits, population and

carbon dioxide levels.

1. Raise or lower the temperature of the culture, slowly,

quickly. Note changes in heartbeat, population levels.

DO level, swimming habits, etc.

26 Project Water Science Water Education Foundation

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DataDesign a chart to record your data.

QuestionsI. What happened to your Daphnia culture when you changed your

variable?

_. How do you think the variable affected the Daphnia population ?

3 Get results from at least one other group. How did their variableaffect the Daphnia population'?

Conclusion


SECTION

3Water And PeopleTeacher% Information Labs 10-12

LAB 10WHERE DOES ALL TR WATER GO?

Distribution in California

ObjectiveStudents will locate major riversand man-made water ways inCalifornia and understand howfar water is transported forurban and agricultural use.

Lab HintStudents will use the CaliforniaWater Map to answer questionson the worksheet. Since not allstudents can use the map atonce, we suggest labs 10-12 berun concurrently with one-thirdof the class working on eachone, then moving on to the next.This can be done with lab sta-tions at different places in theclassroom.

Extension activitiesHave a student trace a drop ofwater from its source in Califor-nia to his or her home. Askyour local water district forinformation about local watersources.


LAB 11

I CAN MAKE A DIFFSIENCEI

WateP Conservation

ObjactiveStudents will become aware ofhow much water differentactivities require and developa personal water conservationplan.

Lab HintsBefore beginning this activity.have the class design a chart torecord the amounts of waterused by each student for eachactivity. Post this chart whereall have access to record results.Discuss ways water can beconserved:

Turn off the tap whilebrushing your teeth.

Don't run the water whileshaving.

Only run full dish and clotheswashers.

Wash cars with a bucket andspray nozzlt .

Sweep outside areas ratherthan hosing them off, etc.

Exteneion ActivitiesHave students graph water usebefore and after conservationplans. Have students calculatehow much water could be savedstatewide if everyone followedtheir plan.

Water Education Foimdation

1AB 12THE MUD MYSTERY...

'1 CAN SEE CLEARLY NOW"

A Water Treatment Inquiry

ObjectiveStudents will understand oneaspect of water treatment: floc-culation.

ReadingPages 8-11, Layperson' s Guideto Drinking Water

lab HintsIf balances are not available toall students, premeasure aluminto 112 gram portions. Cutlitmus paper into small squaresfor testing water. Students willhave trouble deciding why thealum and ammonia causes thedirt particles to form floc andfall to the bottom of the con-tainer. Use the inquiry methodof questioning to have studentshypothesize how flocculationoccurs. Refer them back topages 8-11 in the Layperson' sGuide to Drinking Water.

Extension ActivitiesHave students agitate the alumjar to see if this speeds up floc-culation. Have students reviewother parts of the water treat-ment process.

Possible Research ProjectUse of gray water in cities.Difference between Secondaryand Tertiary treated water.Contact your local water treat-ment plant for a speaker orpossible tour.

Where Does All The Water Go?Distribution In California

Refer to California Water Map for answers.The following worksheet can be assigned as group or individual class work.

1. List the sources of water shown on the map that are within 50 miles of your school.

2. What federal water source is nearest your school?

3. Locate the Sacramento-San Joaquin Delta and describe where it begins and ends.

4. How many of California's rivers are classified "Wild and Scenic?"

5. What is the largest reservoir in the State Water Project (SWP) system?

6. Trace the path of water from the northernmost part of the SWP to the southern end.

7. What California industry is the single largest user of California's developed water?

What percent is this of the state's total water runoff?

8. The Sacramento-San Joaquin Valley and the Imperial Valley are two major agricultural areas inCalifornia. How do their water sources differ?

9. Where does the city of San Francisco get its water?

10. What water source do San Diego and the Imperial Valley have in common?

11. How far does the Owens Valley water flow from its source to Los Angeles?

12. What are some benefits Californians receive from our well-managed water supply?

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San Francisco Bay.

Answers to the California Water Map Worksheet1. Answers will vary.

2. Answers will vary.

3. The Sacramento-San Joaquin Delta begins where the Sacra-mento River branches out north and east of San Francisco andends south of Stockton. It empties into San Francisco Bay.

4. There are ten wild and scenic rivers in California: all of theSmith, parts of the Klamath, Trinity, Van Duzen, Scott, Eel,Salmon, Feather, American and Tuolumne Rivers.

5. The largest reservoir in the State Water Project is LakeOroville.

6. The SWP flows from Lake Oroville south through the FeatherRiver to the Sacramento, through the Sacramento-San JoaquinDelta, splits to form the South Bay Aqueduct and the CaliforniaAqueduct which terminates at Lake Pen-is east of Los Angeles.

Agriculture is California'slargest water user.

The largest user of California's developed water (in canals andreservoirs behind dams) is agriculture (83%). Agriculture uses31% of the state's total runoff.

8. The Sacramento-San Joaquin Valley is richly supplied withwater from many rivers draining into the valley. The ImperialValley must import water from the Colorado River.

9. San Francisco gets its water from the !ietch Hetchy Reservoirin the Sierra via the Hetch Hetchy Aqueduct.

10. San Diego and the Imperial Valley both get water from theColorado River.

11. The Los Angeles Aqueduct is approximately 240 miles long.

12. Californians benefit by having water managed for: irrigation,flood control, fish and wildlife support, improvement of navi-gational waterways, drinking water, water quality control,recreational opportunities, generation of clean hydroelectricpower.


Wild and scenic river innorthern California.


L A B

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I Can Make A Difference!Water Conservation

Background Beadingcalifornia's growth has historically revolved around the chal-lenge of developing and distributing waterthe state's "liquidgold." As in most of the semiarid western United States, the

establishment of urban. industrial and agricultural centers hasalways hinged on the ability to obtain a dependable water supply.

For over a century California has found its large undergroundreservoirs to be one of its major sources of water.

Ground water currently accounts for about 40 percent of all thewater used in this state. The water pumped from California'sunderground basins has been one of the most vital factors in thedevelopment of California as the nation's leading agriculturalproducer and its most populous state. Early California settlers wereable to live in many parts of the state because they could sink wellsinto plentiful ground water supplies.

When agriculture, business, and industry began to flourish, pumpedground water was a major water resource. Then, when pumpingcosts increased and the water table dropped. supplemental surfacewater began to be imported from other parts of the state. Eventhough most of California's ground water and surface water is usedfor irrigation, personal water conservation in landscaping and otherurban uses by a majority of Californians can make a difference.

Materials Needed1. Water Trivia Facts Card

2. Paper and pencils

3. Chalkboard

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Follow-upDid you have to change yourlifestyle?

Did your attitude chance?

What activity of yours requiresthe most water?

! How much water could be savedif everyone in California fol-

. lowed your plan?

JuWater Education Foundation

ActiuitYI . Estimate the amount of water

you individually use each dayin various activities. Usequestions on Water Triviagame as a guide. Write yourestimates on the chalkboardfor reference.

Monitor your personal use ofwater for a day. You shouldwrite each event down onpaper. for example: numbersof times you drank at thewater fountain, washed yourhands, flushed toilets, atecertain kinds of foods. etc.Use the Water Trivia FactsCard to determine the numberof gallons of water used foreach of the events listed.

3. The class should compare theestimates of water used to theactual water used.

4. Add all the gallons used bythe whole class and thencalculate the average bydividing the class total by thenumber of students. Indi-vidual students can thencompare personal waterconsumption with the classaverage.

5. Come up with ways that yourpersonal consumption ofwater could be reduced intimes of drought. Devise aconservation plan.

6. Follow your conservationplan for at least two days.

The Mud Mystery..."I Can See Clearly Now"A Water Treatment Inquiry

QuestionHow do water treatment chemi-cals clean water?

Readpp. 8-11. Layperson' s Guide toDrinking Water

Materials2 liters of muddy water2 clear alass or plasticcontainersalum (112 2rams per I liter)ammoniadropperred litmus paper

ProcedureI. Shake muddy water well to

distribute particles.

2. Divide muddy water into 2clear containers. Label one"Control."

3. To the other add 112 gramsalum. Next add a few dropsof ammonia so that the waterchanties red litmus paper toblue.

4. Test after each drop with asmall piece of paper. Stir orshake each container. Mea-sure the time required for thewater to clear in each con-tainer.

Hypothesis

DataControl time to clear seconds

Alum water time to clear seconds

Results1. In which container did the small particles settle rapidly to the

bottom?

2. How do you explain these results?

3. What further steps are taken in water treatment?

4. Which of these is the most important?

Conclusion

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ti ±Water Education Foundation Project Water Science 88

Glossary

aerateto expose to or supply with air

aerobic"with free oxygen."

algaeaquatic one- or multi-celledplants (such as kelp and otherseaweeds).

anaerobic"without free oxygen."

calibrateto adjust or standardize a mea-suring instrument

choleraan acute, often fatal diseasewhich can be spread throughsewage-contaminated water

climateconditions, such as temperature.precipitation and winds, whichprevail in a particular region

cold-bloodedhaving a body temperature thatvaries with the external environ-ment

contaminantanything that makes asubstance, such as water, unfitfor use (contaminants of watercan include raw sewage, oil orhazardous chemicals)

controla standard of comparison forchecking or verifying the resultsof an experiment culture agrowth or colony of microor-ganisms in a nutrient medium(special food)


daphnia magnaa small freshwater-5..animal, somespecies of whichare used as foodfor aquarium fish

dissolved oxygenoxygen, the gas. dissolved inwater is important for the de-composition of organic waste(such as sewage) in water: alsocrucial to the survival of fishand other organisms living in abody ot' water

distillto purify by evaporating ancthen condensing a liquid, suchas water ecosysteminteraction of living things totheir environment

environmentthe total physical surroundingsof an organism or group oforganisms

floclarge. fluffy particles formedwhen a compound. usuallyaluminum sulfate. is added towater, causing smaller sus-pended particles to clump to-gether. Flocculation (the act ofmaking floc) is often an impor-tant step in water treatment(making water suitable and safefor drinking and household use)


ground waterwater which fills the pores(spaces) between rocks andother materials found beneaththe earth's surface. Groundwater supplies about 40 percentof California's water needs,while surface supplies (suchas rivers and reservoirs) supplythe rest.

hardnessamount of calcium and magne-sium dissolved in water 'Hard"water makes cleaning tasksmore difficult (soap doesn't"suds" the way it does with"soft" water), but some scien-tists believe drinking hard watercontributes to healthier hearts.

hydrologic cycle (also called"water cycle')nature's never-ending process ofevaporation of water from theoceans and the earth's surfaceand its return to earth asprecipitation

larvathe wi.4less, often worm-like form of a newly-hatched insect(plural: larvae)

microorganisma microscopic plant or animal(for example. a bacterium orprotozoan)

organismany living thing (plaat oranimal)

PHa measure of the acidity oralkalinity of a solution. A pH of7 is neutral: higher numbersindicate increasing alkalinity;lower, increasing acidity

planktonplant and animal organisms,usually microscopic, that occurin vast numbers in ocean water

porositybeine permeable, or havingholes or spaces

precipitationwater droplets or ice particles.condensed from water in theatmosphere. which fall tc earthas rain, snow, sleet, hail, dew.etc.

rechargeto replenish ground water byinjecting or allowing water toreach the aquifer (ground waterreservoir) by percolatingthrough the soil

Sampleto take and analyze a specimento determine characteristics ofthe whole

speciesa fundamental biological classi-fication that groups togetherorganisms which are capable ofinterbreeding

toxicharmful or poisonous

turbiditysuspended material in waterwhich affects the water's clarity.or clearness. Measured bywater quality technicians interms of "turbidity units,- tur-bidity is one important measureof how safe water is to drink

typhoidan acute, highly infectiousdisease that can be transmittedby contaminated water

water qualitysuitability of water for an in-tended use, such as household,industrial. agricultural, wildlife.etc.

water tablelevel water stands at in a well

zooplanktonfloating, often microscopic.animals


717 K Street. Suite 517Sacramento. CA 95814

(916t 444-6240

ariDznson' eu!de cfto

enVin_ 0 siaerrPrepared by the Water Education Foundation

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Introduction 2

The Toxics Scare 3

Laws 4

Volatile Organics 6

Water Treatment 8

Disinfection 9

THM Control 10

What You Need to 12Know

Other Concerns 14

Conclusion 16

1991

The Lawerson s Guide to Drinking Water isprepared and distributed bY lhe WaterEducation Foundation as a publicinformabon tool. It is part of a series ofLayperson's Guides which explorepertinent water issues in an objective.easy-to- understand manner

The Water Education Foundation is anon-protit. non-partisan. tax-exemptorganization Its mission is to developand implement educational programsleading to a broader understanding ofwater issues and to resolution of waterproblems

Water Education Foundation717 K Street. juite 517Sacramento. CA 9581419161444-6240

LadedWater EducationFOUNDATION

President: Robert HaganEditor: Rita Schmidt Sudman

Author: Jeanne Duncan

Editorial Assistance: Merle FraserNancy Mathewson

Photos:Aerojet GeneralLos Angeles Department of Water and

PowerMetropolitan Water District of

Southern CaliforniaU.S. Bureau ot Reclamation

On the Cover

Water is tested regularly by California waterpurveyors before beina distributed to thepublic.

Next to 04 water the mnst vitalsubstance for human life WP have to drinkwater in some form every nay Because it isa necessity. we nave come to consider safedrinking water as our right In the UnitedStates we expect to be able to travel fromstate to state ann tind dew quality drinkinghater wnerever we go.

Most public water officials ,n the UnitedStates believe that public onnking water isthe safest thing you can drink It must meetsome of the most stringent standards in theNork.1 Yet many people served by pupiic.vater svstems are huvmg bottled watarma home treatment uevices .md sonic',yen hod their wink ng oialer

Why -s there so mucn alarm? One ooviousreason is the extensive meom attentionthat some water pollution problemshave peen getting Sites of toxicpollution from industrial chemicalshave Peen widely publicizeo and whenground water is affected it sometimesdrinking water source In the few casesNnere public water wells have beenaffected in California the wells have Peenabandoned or the water treated or mixedNith higher duality water to the extentneeded to meet drinking water standardsBecause toxic pollution has frighteningreplications. people also tend to attribute'hose threats to any ievel ot water qualityproblems they Mat dbOul. even vilierecontaminants are found in very minute'races

Scientific evidence shows that the!ear of cancer from long-termeffects of drinking water contaminants isnot well founded, despite the alarmingthings we read in the papers or see ontelevision. The American Cancer Societytells us that over the past 30 years cancerrates have stabilized or declined for alltypes of cancer except lung cancer. Mostdrinking water standards for substancesbelieved to be carcinogenic are set at aevel considered low enough to becalculated as a I -in-a-million cancer riskover a 70-year lifespan. (This does notmean that one person in a million isexpected to get cancer: it means there istan-a-million chance that anyone will.)

According to the Amer-can CancerSociety s icientiticat-on et ma!or risk factor;associated with cancer. only about 2) e oithe total caricer r SK ev(4 C ria beattributable to anv 01 the pollutants,dentified in water. ncluding man-madeorganic compounds. Hiqn lat. !ow iipofdiets. smoking ana alcohol are ioentifieda-- by far the mapor ri nnwn cancer causesBut people reman senoush, comer fledabout the possiail-tv or even trace amounts; canoet-CaUs:no supstances .rt rholdrinkind water One reason !er !heconcern inn ttr't ctandaras- ening ---s that detection tecenniogy easmprovea Markeav teCent .ear,ina,raCe arrolInV; 0r sunstances c.m he Int.womat once went undetected years c!,esearch will be necessary to iino out if anyof these substances pose a scientilicallyaccepted danger n such in nute amountsAnother reason is mat amendments to thefederal Safe Drinking Water Act requirelimits to be set on many more substancesResearch ;S cone to hemp decidewhat the safe lirn ts should be so we hearmore about potential dangers than we oldin the past

There are wide variations ii (Malty amongdifferent water !,oply sources Californiansget their drinking water from Sierrastreams. from Hie Sacramento Son JoaquinDelta. from the Colorado R-yer dna fromlocal sources including ground water wellsThe quality of drinking water has recentlybecome a topic of great interest due to thepassage of the federal "Safe DrinkingWater Act- ano state laws includingProposition 65. the Safe Drinking Waterand Toxic Enforcement Act of 1986.Proposition 65 is designed to prevent thedischarge of unsafe levels of chemicalsknown to cause cancer or reproductiveharm into actual or potential drinking watersources. Another event bringing focus onwater quality issues is the three-year BayDelta hearing being held by the StateWater Resources Control Board Thenearing is to examine all the competinguses of Delta water and consider waterquality impacts on the Delta and SanFrancisco Bay. The end result will include asalinity control plan. pollutant policydocument ank altimately a new water rightsdecision.

The purpose of this guide mr to present the'acts ann :SSUes about today s ahnking.vater in simple easy-to-understand.anguage. It explains what some of themalor concerns and controversial issues,are. what we need to know to resolvethem, and describes the kinds of decisionsNe have to make For additionalnformation on reiated topics. consult theLayperson's Guide to GroundWater. Other easy-to-understandmaterials available from the WaterEducation Foundation include guides toSan Francisco Bay, Delta, WaterConservation, American River,Colorado River, and AgriculturalDrainage.

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The Body's Need forWaterThe body of a normal personweighing about 145 pounds containsabout 40 liters (1.0.5 gallons) ofwater. At the weight of 8 pounds pergallon, the body's weight is morethan half water.

The body loses two to three liters ofwater each day through kidneyfunctions to remove waste,perspiration to help controltemperature, and respiration. Thelost water must be replaced for us tomaintain good health. Thus, mostpeople should drink about two liters,or six to eight glasses of water orother liquids a day.

In a sense, the human body is itselfan aquatic system. The organsfunction by the circulation of fluidsthrough the body. The chemicalprocesses that build and maintainbody tissues and supply energy foractivity take place in the body'saqueous environment,

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The Toxics Scare

,',, renerically to ocs theaarrn U..,laralCsS tne nature

tit,' iit-oun! n guest,on fhs s in oart: nvinv 7! ohtening terms wn Co

zre rig l.r;e(1 .n connection voin these: ,Irot) CA dasOline or solvent

nr1 water rmont be totallyncicctable drop 01 this same..bst rice n a year S SUL)Ply 01 nrinkInn

p. gni not re -In./thing to get e-c.tedii

t!as developed tor rciainomnuric-nt ot 10x CS. nd the

vin,d,nrs tor tnakino rat onai UStinc: onF,Oet.ween various risks and

..ve 0A:00 not Deny) tiearr;f.:ontusea about the clangers

-3ccept an, :ImOt,n.,:nnry

EP4 has a trichloroethylene (TCE)eye carts per pillion as tne allowablerr'7 r, winking water nile the federal

°cog and Drug Administration allowsdecaffeinated instant cotlee to contain25.000 cads per billion (One part perbillion Is tne eauivalent of one crop in ahign sc^001 swimming pool. Or one personin the population of China ) If thesesuostances are really oangerous in suchsmall amounts ro US or future genera-tions e snouta spend the money tOremove them The prouem is. scientistsaon t snow it most Of them are oangerousin ',nose amounts or not

experts cei.eve tetat trace organicorhoounos n drinking water pose little or

-0 -eaittl threat Some researoners believe!flat carcinogens nave to oe over a certain---eshoid to nose s.do:r cant psi, at allOthers argue tnat for any KnOwn

nogen animals any amount posesa !Si< ann none snoula de allowed in puol;c.%ater supplies Reoara:ess of wnichcos t on .s tasen ir s .mportant to realize

ol Inc costs 01 acn.ev no-ero-contamination ,re kmitless

In fact, it will never Pe possible to take outall the contaminants that get into waterRegulations now Deng proposed wit!determine now far we will go in removingthe contaminants from annkino water ancwnere we will concentrate our efforts.

To guide these decisions. the nuolic neeasto be given enougn information todetermine when the risk is trivial. and wnentne risk is pernaps greater and may lustifya large expenditure. One way to focus onfoe facts is to stop reacting to the languageone learn what tne terms mean. Misuse oftne wora -f cxics couia pe resoonsioie 10rmucn 01100 fear apout our orinking water

1--)yJC means boison mc suostance car,egitimateiy pe cescriped as -toxic w:tnout'edam to the amount. (pose orconcentration) to wnicri we are exposed.The term mignt oe aopiied witnout mucnargument to cyanide. "crow). n cotine. orstrychnine. pecause tneir lethal dose for a150-pouna person is only a few drops, butter even these substances there is atruest-told level oelow wnich no significantnarm can ce aetectea or measurea. Today.every substance tnat is known to be poisonin any amount is trequently reterred to as a'toxic chemical-. This terminology tends toobscure the speculative nature of the risks01ey may pose

There are alfferent forms of to>. city Acutetoxicity harms tor even kills) organisms pydoing short-term or immediate damage.Chronic toxicity harms pv caus nglong-term or cumulative effects. sucn as thedevelopment of cancers or certain vascularsystem degeneration Lead, cadmiumsome radioactivity and many of theregulated organics are suspected orknown carcinogens.

Many toxicologists believe that there is noclear non-aamaging tnresnola level forthese chronic toxic suostances Thisconcern, of course, results in a call forlower permissible levels than wouldotherwise be aopropr.ate. In any eventevery toxic material has an exiDosure levelbelow which it is not prudent orcost-effective to mandate removal. Thesearch for that prudent exposure limit is thecrux of our drinking water regulatorydilemma. The inability of scientists to agreeon what the safe limits should be is thesource Of much 01 the confusion about howserious these problems may be. and thepublic s desire tO eliminate all risk makesagreement even more difficult

EMB

MAJOR GROUNDWATER PROTECTION LAWSSTATE OF CALIFORNIA

Law and Enforcement Agency

Porter-Cologne Water Quality Act (1969)SWRCB and nine regional boards

(California has primary responsibility for enforcementof federal RCRA and SDWA. Various agencies areinvolved. primarily Dept. of Health Services. SWRCBand Regional Water Boards)

Title 22, Calif. Administrative Code, DomesticWater Quality and Monitoring Regulations

Department of Health Services

Title 23, Chapter 3. Subchapter 15. CalifAdministrative Code, Discharge of Wasteto Land

State Water Resources Control Board and 9 regionalboards

State "Superfund"

Department of Health Services

Toxic Pits Cleanup Act of 1984

State Water Resources Control Board and 9 regionalboards

Various Underground Tank Control Laws

DOHS. SWRCB, logal agencies(Local agencies, usually county health, publicworks, or fire departments are responsible forpermitting and monitoring. When groundwaterhas been impacted the regional boards are usuallyrequested to be the lead agency to enforcecleanup.)

Solid Waste Disposal Site Prioritization, WaterCode Section 13273

SWRCB and regional boards

Monitoring of Large Public Water SystemsAB 1803 (1983)

Department of Health Services. SWRCB andregional boards

Provides for

Protection of the quality of surface waters of the state.

See federal laws.RCRAhazardous waste controlSDWAdischarge of contaminants to drinking water

Public water suppliers to regularly monitor systems for certaincontaminants in drinking water and report results to DOHS. Lists primaryand secondary drinkirv standards. (Constitutes California's equivalentprogram to EPA SDWA standards.)

Regulation of discharges of hazardous. "designated" and solid waste tolandfills, waste piles. surface impoundments, and land treatment units fortreatment. storage. or disposal. Requires zero discharge and monitoringfor hazardous and designated waste.(Constitutes California's RCRA equivalent, with other DOHS regulations.)

$100 million program established in 1981, and funded by taxes collectedfrom waste generators, for cleanup of hazardous sites. Amended andincreased in 1984 with passage of bond issue.

No discharge of hazardous wastes within 1/2 mile upgradient of a potentialdrinking water source by 6/30/88. and closure by 1/1/89 of surfaceimpoundments unless double-lined, provided with leachate collectionsystem. and monitored

Reporting, inspection, permitting, monitoring, testing, double containment,repair or removal of leaking underground tanks. 1987 amendmentsextended regulations to certain farm tanks.

SWRCB to test and rank all 1200 solid waste (garbage) disposal sites in thestate. 150 sites to be tested each year until all have had solid waste waterquality assessment test (SWAT). A SWAT is one-time air quality.groundwater and vadose monitoring to see if hazardous wastes areleaking from the landfill.

DOHS to monitor all public water systems for contaminants, regional waterboards to review data and identify discharges which have affected thepublic drinking water wells. (Later amended to include small systems.)

Law and Enforcement Agency

Proposition 65. Toxics Initiative. Safe DrinkingWater and Toxic Enforcement Act of 1986

Lead agency Health and Welfare: Advisory Group.secretaries ot Business. Transportation. andHousing Agency. Environmental Affairs andResources agencies and directors of Departmentsof Food and Agriculture. Industrial Relations. andHealth Services.

Provides for

3overnor to publish a list of chemicals "known to the state to causecancer or reproductive toxicity," to be updated annually March 1.Reauires dischargers of any listed chemical to warn any individual whomay ne exposed Prohibits discharge of any amount of a listedchemical where It might reach potential water supply unless dischargerproves there is no significant risk or observable effect Provides forpenalties and citizen enforcement actions with filer's sharing ofpenalties with enforcement agency and superfund.

MAJOR PROTECTION LAWSFEDERAL

EPA to set national standards for drinking water quality. Maximumcontaminant levels (MCLs) to be set for a wide varietyof contaminants toestablish maximum allowable concentrations. Local water suppliers to

monitor public water supplies to assure that MCLs were not exceeded, andreport to consumers if they were: and to achievecompliance.

Safe Drinking Water Act (SDWA) 1974Amendments (1986)

U.S. EPA and enforced by State

SDWA Amendments

U S EPA and enforced by State

Clean Water Act(Protects ground water indirectly by protectingquality of surface water.)

U S. EPA and enforced by State.

Resource Conservation and Recovery Act(RCRA)

S EPA and enforced dy states

RCRA Amendments

Comprehensive Environmental Response,Compensation and Liability Act (CERCLA)(known as "Suoerfund")

Federal Insecticide, Fungicide andRodenticide Act (FIFRA)

Toxic Substances Control Act (TSCA)U.S. EPA

EPA to set standards (MCLs) for 83 named contaminants within 3 years.

Local water supply systems to monitor for a broad rangeof contaminants

besides those with MCLs.EPA to require filtration and disinfection of surface supplies notadequately protected and to consider disinfection for ground water

supplies.Grant programs and tecn meal and financial assistance tosmall systems

and statesStrengthened enforcement authorityGrant program for designating sole source &Killers for special

ProtectionBan on future use of lead Pipe and lead solder.EPA to evaluate monitorng methods for oeeo well injection waste

disposal sites.Well head protection program

EPA to set standards for surface water, require sewage treatment, and limit

discharge of industrial and municipal wastewater into surface waters.

EPA to develop regulations to track wastes from 'cradle to grave coveringgeneration. storage. transport, treatment. and disposal of hazardouswaste. Protects all sources of groundwater from contamination byhazardous waste Also pronibits pollution of surface water and air by

hazardous waste sites.

Reauthorization and amendments to increase thenumber of waste

generators sublect to regulation and placement of underground storage

tanks under EPA regulations.

Fiinds and EPA authority to clean up existing hazardous wastesites based

on priority of threat to water or other resources Also creates liabilityprovisions for federal and state to seek reimbursement from responsible

Parties (generators. transporters. or disposers) for cleanup. or to seek a

court order requiring those responsible to clean up a site

EPA to regulate pesticides and toxic substancesthat may have an adverse

effect on the environment, including groundwater and other drinking water

sources.

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Even the word 'chemicals has acquired afrightening connotation, partly because it isso often linked with "toxic' and-dangerous- Every substance in the worlds made up of chemical compounds of afew more than a hundred basic elements.We use those same elements to create'man-made chemicals". A piece offirewood has thousands of chemicalconstituents in each fiber. Water is achemical compound. So is everything else

Scientists use these terms in their work sothey do not have the same emotional,eaction to the words When we look at.vnat the words mean, they tend to losesome of their power to frighten One of thebasic elements, carbon. is present in everyliving thing. Chemical compoundscontaining carbon are called -organicchemicals Organic chemicals make uomost of the foods we eat.

Then there is another term. 'volatileorganic chemicals-. or VOCs.Volatile, richemical terms, does not mean explosive:-I simply means it evaporates readily atroom temperature. Volatile organics can besomething unpleasant to breathe, likegasoline fumes, or as sweet as the scent ofgardenias or orange blossoms. (The termvolatile or even -aromatic-, has nothing toJo with scent but if you can smell it in theair something has )ecome volatile or itNoulon't reach your nose. There arevolatile chemicals that have no Perceptibleodor )

Volatile organics can be removed easilyfrom drinking water because they arenclined to evaporate readily However, it isexpensive to remove them from largeamounts of ground water because largequantities of water have to be pumped.The most common treatment involvesforcing air upward through a tall column otpacked materials over which the pumpedNater trickles downward The chemicals'hen volatilize (evaporate) out of the waterand into the air

This is not to say that some chemicals arenot harmful. We know some are just from'he ones we use in our homes, likeiimmonia and chic eine bleach Most of ushave learned to be cautious in using thesechemicals. and as a society we are-earning to be more cautious about them inthe environment

But because ,y.e are farna:ar withhousenolci c.eaners ang solvents, they donot carry the same trepidation for us asbnemicals with mysterious names. likeTCE Many a' the substances that get intodrinking water nave been identified ascarcinogenic or -potent:ally carcinogenicWhen evaluating reports of carcinogens inour water, the things to consider are tneamounts in Question as well as the basis'or their being described as carcinogenic

Whenever there is a higher than normalnciaence of cancer or Dinh defects in a

community something toxic in the waterpecomes a Or me suspect Tliis :s a'easonable ryace to start looking becausewater is one of the fundamental thingseveryone affected has in common.However, the problem could also comefrom many other sources. such as the air.food, common building materials in thehomes. a common work-Place, or evensubstances naturally occurring in the soil.

Many of the regulations now being set toprotect the environment are placed farbelow the exposure levels we have fromother sources in everyday living. Theseregulations are being demanded by thePublic. and legislators are responding bypassing new laws each year. Critics of.ncreasing'y strict standards warn thatthese laws will cause the price of water toskyrocket. and yet accomplish very little,unless efforts are concentrated oneliminating tee most serious health threats.

Progress is being made in developingmethods to assess risks and to put them.nto meaningful perspect;ye. however it isstill a very primitive field. As scientists withdiffering viewpoints begin to explainrelative risks in understandable terms. thepublic can begin to make better informeddecisions about "how safe is safeenough")- and other similar questionsHowever, subjective factors will continue toinfluence puolic opinion L ke most of ourwater problems, this one nas no easysolution. It does seem clear that betterdecisions will be likely if we can reduce thenfluence of panic at the word "toms-

(4-

What Happens from theSource to the Tap?Water treatment technology is remarkablen cleansing -the universal solvent from ailthe potential perils from its source to ourtap. Clear mountain springs might be`lowing through sulfur, arc. orarsenic-laden soils. Lakes. rivers, andaquifers can pick up contamination suchas nitrates from fertilizers or septic tanks.'tom acid mine drainage, or naturallyoccurring minerals. Rivers and streamssometimes carry harmful bacteria fromanimals and the risk of disease.Storm-caused urban runoff can also carrypollution .nto rivers and streams

Pollutants can also enter the water fromagricultural drainage and runoff, and fromwastewater discharges. Other potentialsources of pollution are landfills and otherNaste disposal sites, where rain water cansoak into the ground and leach out harmfulsubstances and carry them into watersupplies In our homes, factories. andbuildings corrosive water can dissolvemetal in the pipes, such as lead solder. Orcan be contaminated by accidentalcrossconnections with nonpotable watersources

Yet these potential routes of contaminationhave been explored for decades, andmany of these problems have been solvedThough they still have to be guarded-against. they are well understood. Waterquality professionals have developedmethods to detect them, measures to avoidthem, and modern treatment techniques toeliminate these harmful effects before theNater is delivered to consumers of publicNater supplies

Despite concerns about possiblec.:ontamination of future watersources, existing supplies of publictap water in the U.S. areunquestionably safe to drink Wherepublic water is available, it is rarelynecessary for people to spendmoney to buy bottled water or installhome treatment devices.

Current and proposed EPAregulations on the quality of drinkingNater in the U.S. ensures consistent.good quality drinking waterthroughout the country. Researcherscontinue to study the long- termeffects of contaminants that mayoccur in the water supply.

What The Letters MeanMCL Maximum contaminant level set by EPA for a regulated substance in drnking

water. The MCL must be set as close to the Goal (MCLG) as feasible, usingbest treatment available considering cost.

MCLG Maximum contaminant level goal set by EPA for each regulated substance indrinking water. The goal is to be set at a level at which no known oranticipated human health effects will occur allowing an adequate margin of

safety.

TCE TrichloroethyleneA VOC used as a degreaser or solvent (commonly used inindustry, dry cleaning, and household carpet cleaners).

THMs Trihalomethanes Any of several synthetic organic compounds formed wrienchlorine combines with organic materials in water. One of the most commonTHMs is chloroform.

THMFP Trihalomethane formation potentialDepenos on amount of organic materialpresent .n water to combine with chlorine to form THMs.

VOC Volatile organic compound--A chemical compound which evaporates readilyand contains carbon. Regulated VOCs include both chlorinated organiccompounds, such as ICE, and aromatic organic compounds. such asbenzene. VOCs are used as solvents and degreasers, and are present in fuelssuch as gasoline.

-Air stripping systems f:an remove VOC's from millions of oailons of water per day.

I 4,

What About Trace Organics?

The biggest challenge today is in dealingwith newly discovered problems that mayor may not pose real threats to publichealth Because of our ability to detectminute traces of substances in groundwater, we have leatneo that ground wateris not contaminant-free, as we oncebeileved. Testing of around waterthrougnout the country has uncovered thepresence of .ndustrial and agriculturalcnerncals. gasoline tram leaking tanks.ago other substances that have percoiated,nto ground water supoiies.

H rre past many people did not believeHat aumoing ot these c.lemicais wouldcose significant r.sk. Contamination otground water can be a serious problem if t

s extensive, because the contaminantgenerally travels slowly and unobserveduntil it reaches a water supply well andeventually is oetected. By then it hasdispersed in the ground water and is moreoifficuit to remove.

Another disquieting discovery in recentyears was that Prinking water can acauirenew chemicals even from the treatmenttecnniques used to disinfect itTrihalomethanes. or THMs.are formedas cnionne is aided and combines withnaturally occurring organic material in mostsurface waters. Because THMs.sucn aschloroform. are suspected humancarcinogens, some people fear that theymay be harmful over many years ofexposure. even in the trace amounts thatthey occur. Water utilities are taking variousactions to reduce THMs while continuingto assure adequate disinfection.

On a relative scale, the potential dangerposed by trace organics formed in watertreatment is insignificant, considering thatthe use of disinfectant (mainly chlorine) hasv.rtually eliminated life-threateningmicrobiological epidemics from U S watersupplies for over 70 years and has givenus longer life expectancy In that context.our concern about traces of substancesthat might possibly cause a low levelcancer Increase if ingested over a lifetimemight appear out of balance with otherpublic health concerns Yet it is becausewe continuously examine new informationana take a fresh look at past assumptionsthat we continue to improve th .diety anareliability of our drinking wa'

ERerf _reEtfin [rA

Water Treatment

The glass of water you are about to ar Okhas a long and glorious past. It may oncehave coursed down the Ganges. orsplashed into Julius Caesar s bathing pool.The water we use now is the same supplythe human race started with The totalamount in the global cycle remainsessentially constant, though its distribuf onis continually changing. Its quality isrenewed through the hydrologic cycle inthe cycle water evaporates from riverslakes, ana streams ana goes into the a r aswater vapor. wnere it returns in the tom- ofprecipitation ra.n. snow. sleet or nai

Surprisingly though. 000cl duality drink nowater coos not lust fall from the sky Agreat deal of trouble and expenseandadvanced technology goes into mak.ngour public drinking water supplies safe todrink.

Rain water has already acquired impur tieseven as the water molecules collected intodrops. Particles of dust, smoke and sats inthe atmosphere combine with the waterAirborne gases. such as carbon dioxide.sulfur dioxide ana nitrogen oxide mightalso combine with the droplets to formweak acid solutions When the drops reachthe earth, they break down rocks.dissolving minerals in the rocks and saiThe water, which was briefly composeaonly of two atoms of hydrogen and oneatom of oxygen. now has minerals sucn assodium. chloride, calcium, iron. andmagnesium both dissolved and suspended

11 It.

Water is called "the un.versal solventbecause in all its forms: ice, liquid or vapor.1 is affected chemically by the materials itcomes in contact with. Besides its chemicalalterations from contact with earth ana sky.water also has biological aspects.Organisms. plants. and animals live inwater. and its physical and chemicalproperties affect its suitability for theirhabitation. Conversely. their habitation ot.vater affects its suitability for us to arinkAlaae can make water smelly andunappealing, but a more insidious prooiem.s the disease-causing organisms whichcannot be tasted or seen. from organismsin the fecal matter of animals. such asmuskrats and beavers and land animalsncluding humans.

A century ago !se n.ggest concern otpublic water suppliers was controllingwater-borne alsease. Before aisinfectionbecame a common practice, widespreadoutbreaks of cholera ana typhoid werefrequent throughout the U S Thesediseases are still common in lessdevelopeo countr es. but disappeared nthe U.S when cnionne became widelyused more than 70 years ago.

Good Drinking WaterWater used for dr nking ana domestic ....seshoula taste am] and ne free 01t,npleasant 000rs t ;.riouid be tree 01gisease caus.no croan:sms ana not containany substances a! :eyes :oat could benarmful or tox.0 7 nflouia look clear ananot be si.my or c scolorea its pH balanceshould be in a neutral range so as not to betoo acidic or aikame It should not oecorrosive to pipes or plumbing

Turbidity. or clarity. of water was onceconsidered chiefly an aestheticconsideration. out 1 .s now a primaryregulation for puplic arinking water Th:simportance is placea on turbidity becauseparticles suspended in water can shieddisease organisms ono allow them toescape the etfects of aisinfection

Today our dunking water supplies arebeing increasingly regulated for everycondition known or oven suspectea. toaffect human health A public watersupplier operating a treatment systemtoday has methods to control nearly ali theproperties of the water hardness. acidityand alkalinity, color, turbidity. taste andodor, as well as trie biological and organicchemical characteristics. Large watersuppliers maintain their own laboratoriesequipped to test water for all theseproperties and constituents. Wateragencies in smaller communities usecommercial laboratories.

Despite ail the care aria treatment we giveour drinking water it is an ever-changing.evergrowing task to assure its safety. L kewater. which is never static, the rest of theenvironment is continually changing anaour knowledge of it increases with eacnadvancement in the environmental anahealth scences Most public surface watersupplies receive full conventional treatment.All public supplies Probably wil soonunless they can pass stnngent standaras.because of proposea new EPA surfacewater ano ground ...ater treatmentrequirements

Conventional Treatment

Coagulation/Flocculation

Coagulants such as aluminum suitate.ferric chloride or organic polymers arerapidly mixea .nto the water This alters theelectrical charges surrounding thesuspended particles to make them attractand coagulate, or clump together .ntolarger particles known as floc Inflocculation, the water is gently agitatea so!he floc particles will collide with each otherann entrap other suspended particlesfnrrning still heavier particles

Sedimentation

The flocculated water moves slowlythrough a basin or tank to allow the neavifloc particles to be removed by settling tothe bottomCoagulation/flocculation/sedimentationsteps reauce turbidity by removing many ofthe particles that cause water to appearcloudy

FiltrationWater is passed through filter media madeof sand. coal particles or similar materialsto remove small. light particles that do notsettle. This process further reducesturbidity and results in water that is crystalclear. Filters are backwashed frequently toremove accumulated materials.

Disinfection

Chlorine. chloramines. ozone. or anothertype of disinfectant is added to destroypotentially harmful bacteria. viruses, andother organisms. Enough chlorine is addedto leave a residual amount of chlorine in thewater, to continue to kill any pathogens inthe pipelines that convey the water to users

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LemonJuice

Vinegar

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What pH Values Mean*

CleanRainfall

NEUTRAL

BakingSoda

SeaWater

Ammonia

ALKALINE(Higher Numbers)

5 6 7 8 9 10 11 12 13 14

ke--- Acid Precipitation

Each number represents a tenfold increase or decrease in acidity.

Other ProcessesAeration

Aeration :me mixture of air with water. 'si:ometimes crone a undesirable amounts orron and manganese are present. they aremeld in soiution in water only in theabsence at oxygen Aeration also removesgases dissolved in the water Aeration isdone or manly to improve the aesthetics ot...rater color. taste and odor.

Corrosion Control

Other crernicals may be added to waterduring tre course ot treatment for specificpurposes Caustic soda or lime may beadded to control the corrosiveness of water

adiust no the water s pH. Sometimescompiexes of phosphate or silicate areused for tr s purpose

Fluoridation

in some systems, fluoride is added to heir)reduce tooth decay in children. Fluorideoccurs naturally in some water supplies.Ind the amount which can be in drinking.,,ater is regulated by EPA

Disinfection: Is ChlorineGood or Bad?

The use of chlorine for disinfection is anexample oi the choices society has to facewhen there is a risk/risx situation and adecision must be made about which f:SiCoutweighs the other. The known risks fromnadequate asinfection are far greater thanpotential r isks from traces of organiccompounds.

Since 1914. chlonne has been thepreferred disinfectant in most United Statespublic water systems Although there areother methods of disinfection. chlorine hasteen considered the most reliable forcontrolling water-borne disease It isrelatively easy to use, inexpensive, andwhen it is added to water it remains.continuing to K.il bacteria in the distributionsystem.

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In the late 1960's and early 1970's.scientists began to be concerned aboutnewly-discovered compounds that areformed when chlorine combines withnaturally occurring organic materials, suchas humic or fulvic acids from soils ordecaying vegetation. These syntheticorganic compounds. the most common ofwhich is trihalomethanes. or THMs.were first discovered when new laboratoryequipment was developed with thecapability of detecting chemicals inamounts as small as one part per billionTHMs were not known to be harmful in theminute amounts detected. but no one wassure what their long-term effects might be.When they were found to be carcinogenicto test animals (and suspected humancarcinogens), disinfection by-productsbecame the subjects of intense research todefine the r harmful effects

With the discovery of THMs. chlorinationhas been called Into question. Most wateragencies .n the U S. use chlorination as theprimary a sinfectant. There are othermethods of disinfection which do not formTHMs. or form fewer THMs. but thealternatives are not equally effective torevery system Also. the other methodssometimes nave problems of their own.

Disinfection TreatmentAlternatives

In 1979. EPA set a max mum contaminantlevel (MCL) for THMs a: 100 parts perbillion (or 0.10 mg/l). Some agencies werenot able to meet this standard usingchlonne. and chose to iose other methodsof disinfection. In 1985. :ne MetropoiltanWater District of Southern California (MWD)began to use a chlonne-ammoniacombination. called ch:cramines. ...nicngreatly reduces the forrhation of -4 Ms.MWD first conductea c at stuoies to test tseffectiveness, and deternen thatU.sinfection with chlora- nes cou:o be aseffective as chlorine ca etenaina thecontact time and using coionne in :nodistribution system. Ch oramines havebeen used by other ma or utilities n theU.S. for many years aho tnis disintectionmethod is gaining in popularity

Ozonation. a disinfect on Process usedwidely in Europe. does oot form THMs. Ithas been used less in r.he U.S primarilybecause of cost. Ozone s effective forcontrolling color, taste ana odor its maiorpublic health disadvan:age is that ozonenoes not remain in the ...ater to ais.nfectthroughout the water c str.bution systemTheretore. cnlorine or aoother disinfectant-host be used also. ai:rough less i.t.oula beheeded than if chlorne a one were usenT-ere is some THM fcr-ation but lessthan with disinfection ted to cr'orine

Some aaencies use ozo^e to meetfeauirernents unrelated to controi of THMs.in 1987 the Los Angeies Department ofWater and Power began using ozone fora:s nfection in its new ...ater filtration planttreating its Los Angeles Aqueduct supplyOzone was selected or -iarily for tseffectiveness in reduc ha turbidity. sincetr'e Department was .t.e below allowableTHM limits. but the use of ozone ann other'actors have further rea,ced THMs in thewater. The efficiency ct the plant wasocreased and fewer coagulant chemicalsre used with the ozo^e process The LosAnne les Department ct :iater ano Poweroontinues to use chlcr he for disinfection in's g stribution system

Ultraviolet ana ionizing raaiation are otherdisinfection methons that do not produceTHMs. These cose some concerns of theirown. and may have unknown side effects.Chlorine dioxide is another alternative tnatproduces few THMs. However. I hasproduced harmful effects on the blood ntests with animals and may produce otnerinorganic and organic tav-orooucts

Studies are being done to investigate thepotential carcinogenic or mutagenic effectsof all disinfection metnoas Because of :assfrequent use. there are less aata on thepotential et',::cts at cn:oram.nes ozone or,-)ther methods ces,des c-or,ne ihn th.,res some indicaton that tnere 1)0

problems with trem eauai to ihe concernwith THMs.

Obviously, the proolem s morecomplicated than lust p.cking anotherdisinfection method They are not ailequally feasible for every system Thechoice depenas on wnat is iikely to be inthe water, as wen as hoid:ng I rne ;ndistribution lines Some People may bemore sensitive to the effects ot onedisinfectant than another Many experts are.n favor of using chlorne simoiy because :1has been effect..iely risen for more thanseventy :ears ith relatiyeivl.ttle evq]enceof serious problems

THM Control

The EPA maximum contaminant level forTHMs is 100 parts per billion

According to a study funded by theAmerican Water Works Association.published in 1984 the existing regulationresulted in a 40 to 50 dercent reduction inaverage THM levels in tne U S . at a costof between S31 million and $102 millionThe next increment of reduction, if thestandard is reduced to 50 ppb or lower.will cost billions and result in the inabilityof many utilities to comply, the studyconcluded

On the basis ot the information availablenow. an EPA source says ne wouldhesitate to say that chlorination should beavoided The hea" effects of THMs arestill debatable. anti other treatment mayhave similar effects

Even ii technical experts favor a standardthat would leave the options open for watersuppi:ers to select the optimal nisinfectionstrategy for their systems to get the bestputalic health protection. EPA policy maynictate otherwise Chloroform. the mostcommon THM. is classified as a Probablehuman carcinogen, and therefore requiresthe maximum contaminant leve! goal(MCLG) to be set at zero. By law theMCL must be as close to the goal as isteasiole. If the THM standard is set even,ower. manv systems va be unable to meet

In chlorine and will nave to use other',It:es cmniect rn

Reducing THMs At TheSource

Some water sources have more organicmaterials than others. and thus havegreater potential for THM formation whenchlonne is added. The Sacramento-SanJoaquin Delta has been found to nave nighlevels of these THM -precursors . andoonseguently a high trihalomethaneformation potential (THMFP) If theseorganics could be prevented from enteringihe water. the formation of THMs could be--, an '.cantly reaucen. however :1 s unlikely'hat a mator THMFP reduct:on can beachieved in water passing througn theDelta The chlorine/THM reactions areenhanced by bromides from sea waterwnich enters the Delta from the PacificOcean Agricultural drainage ana the SanJoaguin River also contain bromides. sothere are other sources besides the oceanThe primary source of organic THMprecursors in Delta waters is from naturallyoccurring organic substances wnich aredissolved from Delta peat soils and soils inthe watershed tributaries Further stuniesare being done to ioentify the maiorsources of THM forming materials in Deltawater supplies

Forty percent of the state s surface watercomes from the Delta. and the Deltasupplies drinking water for millions ofCalifornians. II it is not feasible to reducethe THMFP there, agencies us;no cnlonneto disinfect Delta water will have to rely ontreatment for precursor or THM removal orseek alternative points ot intake not soseverely affected by Delta conditions

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The Delta waters tive high levels of THM "precursors."

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'9.77,01.4;3 THM Removal By Treatment

If chlorine is considered to be the bestmethod of disinfection by a water supplier,THM levels can be reduced before thewater is delivered to the consumer.although this is an expensive undertaking.The feasibility of removal through airstripping or filtration with granular activatedcarbon (GAC) is being studied by EPA andwater suppliers.

Good THM control, along with disinfectionand reduction of many other organicconstituents is being obtained in pilotplants using "advanced oxidationprocesses" (AOP's). These processes usecombinations of ozone. hydrogenperoxide. and UV light to produce hydroxylradicals, one of the most powerful oxidizingagents that can exist in water. Researchersat UCLA and MWD, with somesponsorship from the American WaterWorks Association Research Foundationhave recently done pioneering work on useof AOP's for large-scale water treatment.They use the term "Peroxone" for treatmentwith peroxide and ozone. They findexcellent reductions of THM's at a fractionof the cost of teatment by GAC filtration.

Because of costs and uncertain benefits.municipal water districts have beenreluctant to install THM removal systems.or other non-required safecluards.However, large water suppliers arebeginning to take another look at providingadded water quality assurance to theircustomers because so many customers areinvesting in home treatment devices andbottled water. The fact that so many peopleare willing to pay higher costs for water,hoping to get better quality or taste. hascaused many water purveyors to believethat consumers will support additionalimprovements to be better satisfied withtheir municipal water service.

Although individual water users can buyGAC filter systems. they lack the ability todetermine if the filtration system is workingproperly. Unless filters are changedregularly, such a system could addcontaminants instead of removing them. Ifthe supplier furnishes treatment for allusers, the overall cost is lower and there isassurance that the system will bemaintained routinely by trained personnel.

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Should You Have Your WaterTested?

If you get your water from a private well,experts say you should have your watertested at least once a year for bacteria.This test will cost about $12 at most waterquality laboratories. Shallow wells alongrivers and wells built without propersanitary seals are especially susceptible tobacterial contamination from surface waterentry.

If you are concerned about "toxicsubstances", the tests will cost much more.Testing for minerals can cost from $130 to$200. Testing for organic "prioritypollutants" may cost an additional$200-$300. Testing water for everyth'ngthat might conceivably be in it rea,more extensive tests that can cosi everalthousand dollars per sample. Fortunately, itis usually not necessary to check for the fullrange of pollutants. Chances are otherwells in your area have been tested. andyour county health department is probablyfamiliar with the soil composition andaware of metals or other possiblecontaminants of concern in your vicinity.County and state health departments keeprecords on well trouble spots, and canmost likely tell you whether any substancesof concern have been found in wellsnearby.

With EPA funding assistance, the SantaClara Valley Water District in San Josepublished a booklet "A Guide for thePrivate Well Owner", to answer questionsabout well contamination. Water Districts inother areas may have similar publications.

If you receive water from a public watersystem. you can usually get the informationyou need without having to go to theexpense of having it tested yourself. Publicwater systems must have surface watersupplies tested at least once a year. andwells tested every three years. Mostagencies, especially larger ones, test thewater much more frequently. If you receivea monthly bill for water, the agency thatbills you can probably tell you what thewater has been tested for, how often, andwhat the results were. California state lawrequires all public water agencies toprovide the results of their routine testing toconsumers upon request.

If you cannot find out who your watersupplier is, call the health department inyour county. Records of testing of publicwater supplies are sent to county and statehealth departments.

If you notice an unusual color, taste, orodor in your tap water, you should report itto your local water agency. The agencycan probably explain to you what thecause is and what is being done about it,as well as any steps you should take to besure the water is safe to drink. If theproblem you describe is a potential healthproblem and they are not aware of it, theywill most likely test the water. If you chooseto have your water tested for any reason,you should use a laboratory that is certifiedby the state to conduct the type of analysisyou desire.

Should You Boil Your Water?

If you have a private well and suspectbacterial contamination, boiling your waterfor 15 minutes will kill all disease-causingorganisms. If you receive your water from apublic supplier, there is frequent testing forbacteria and you would probably bewasting energy unnecessarily.

Exceptions would be when the integrity ofthe supply is in question (for example. afteran earthquake), or if you expenerbreak in your water mainline, or t, pebetween the house and the street wherebacteria could enter the distribution pipesin your house. Most public water supplierstest water as it leaves the treatment plantand at the most remote points in the line, tobe sure their entire distribution system isbacteria-free.

Another potential trouble spot is at the veryend of a waterline if connections are fewand there is not enough use to keepdisinfected water flowing in the line (mostare looped to avoid this problem). Yourwater supplier will alert you if a disaster oremergency requires that you boil yourwater.

Boiling the water will also remove volatileorganics, including THMs formed inreaction with chlorine. They will bereleased into the air in your kitchen, and bedissipated into a large volume of air so theamount you actually breathe would besmall. Metals dissolved in the water andcertain compounds, such as nitrate, are notremoved by boiling. In fact, as you boil thewater and some of it evaporates, thesesubstances become more concentrated.

Bottled Water or a HomeTreatment Device?

If your water is from a public watersupplier, there is no reason to look foranother source of drinking water unless youdon't like its taste. In California bob; publicand bottled water supplies must meet thesame state and federal drinking watersafety standards. However, mineral water isregulated as a food and does not have tomeet drinking water standards. Bottledwater could be from the same source asyour public water supply, although mostbottled water has been put throughadditional filtration. The amount and type ofminerals in bottled water depend on itssource and the type of treatment it receives.

The same questions should be askedabout bottled water as about public watersupplies. You need to know the quality otits source, and what its treatment has been.

Bottled water suppliers in Californiasupported state legislation that increasedtheir performance standards over publicsupplies in three areas: THM's, lead andvolatile organic compounds. However,many water utilities already meet strictstandards in these areas.

A home treatment device is unnecessary ifyou get water from a public supplier. Ifsome individual taste preference or otherconcern makes one desirable, it isimportant to be sure the system is servicedregularly and will serve the intendedpurpose. Bacterial contamination is a riskfrom dirty filters in home systems. Filtrationsystems in public supplies are routinelyserviced and maintained.

If you get your water from a private well orprivate water system and you areconcerned about its quality, you mightwant to get a Point of Entry (POE) deviceto treat all the water that enters your home.The other major type is a Point of Use(POU) filter, which treats the water only atone faucet. Within these two categories,there is a wide variety of treatment units.each for different purposes. Before buyinga treatment device, it is important thedevice be appropriate for your needs. ThePacific Water Quality Association inHuntington Beach, California is a nonprofittrade organization for the home treatmentdevice industry you can contact. RecentCalifornia laws require state certification ofhome treatment devices and truth inmarketing to protect consumers from false claims.j

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Lead in Drinking Water

One of today's concerns that all the expertsseem to agree on is that lead is harmful,whether it is ingested in water or inhaled inthe air. Lead accumulates in the body, andtoo much can cause serious damage to thebrain, kidneys, nervous system and redblood cells. Infants, unborn children, andyoung children are especially vulnerable tolead poisoning because they can receivemore lead per body weight than adults.Infants on formula have the greatestexposure from lead in water because it issuch a big part of their diet.

In recent years federal controls on lead ingasoline, paint, and "tin" cans havegreatly reduced the overall exposurepeople have to lead. The amount indrinking water has therefore gone from arelatively minor contributor to one of thesignificant remaining sources.

Lead in water supplies is rarely due to thepresence of the metal in the water source.If lead occurs naturally in the water, it isremovable from public supplies throughtreatment processes. In the cases wherelead is above safe levels at the tap,plumbing materials such as old lead pipesor lead solder in copper pipes in the homeare almost always the source of the leadcontamination.

Both state and federal laws were recentlypassed prohibiting the use of lead pipesand lead solder. These laws, resulting inchanges in building codes, will protectpeople in newly constructed homes andapartments from lead in their drinkingwater.

The amount of lead dissolved from pipes orsolder depends on the aggressiveness ofthe water (unless treated, soft and/or acidicwater is more corrosive), the length ofcontact time between the water and thepipes, and the age of the plumbing. Olderplumbing may have developed a protectivecoating, especially where there is hard water.

Concern for the effects of lead on childrenled the EPA in 1991 to direct virtually everywater supplier in the nation to test tapwater for lead. The new rules reduce theold standard of 50 parts of lead per billionparts of water to a two-phase standard of15 parts per billion at the tap and anaverage of 5 parts per billion throughoutthe system.

nerr C ncertnaWhat Can You Do AboutLead in Plumbing?

Generally, most homes older than fiveyears have developed a protective coatingon pipes and there is little risk of elevatedlevels in older homes.

Water suppliers can treat public supplies tomake the water less corrosive where lead isa known problem and replace any oldwater mains and service connectionscontaining lead.

Families can have the water from their taptested for lead This may cost from $20 to$80 per sample at a laboratory certified fordrinking water testing. The test shouldinclude a "first draw" sample and a "fullyflushed- sample. (The first-draw sample willhave the highest level of lead, while thefully-flushed sample, taken after running thewater tor 5 to 30 seconds, will indicate theeffectiveness of flushing the tap beforeusing the water.) Most laboratories willfurnish sample containers and instructionson how to draw your own tap watersamples.

For more information, contact your localwater supplier or county or state healthdepartment. These agencies can also helpyou find laboratories certified by EPA oryour state as qualified to analyze drinkingwater samples for lead. You may find aqualified testing laboratory under"Laboratories- in the yellow pages.

What To Do If You FindHigh Lead Levels

In the rare incidences where you do have ahigh lead level in your water, follow theseprecautions: Never cook or drink waterfrom the hot water tap. Hot water dissolvesmore lead more quickly than cold water

Always use water from the cold tap tomake baby formula. Boiling the water willkill disease-causing bacteria, but does notremove lead. If you have been instructed toboil the water, you still must begin withcold water because hot water will havemore lead dissolved in it. Never drink orcook with water that has been in contactwith your home's plumbing for more thansix hours, such as overnight or during yourwork day. Before using water for drinkingor cooking run the water until you can feelit get cooler to "flush" the cold waterfaucet.

If you own a well or private water source.you can treat the water to make it lesscorrosive. Corrosion control devices forindividual households include calcite filtersThese should be installed in the linebetween the water source and any leadservice connections or lead-soldered pipes

Asbestos In Drinking Water

Asbestos is a fire-resistant fiber found ci themineral serpentine, a greenish mineral socommon in California it has beendesignated as the state rock. Because ofthe widespread occurrence of serpentineasbestos is common in some of California swaters. Serpentine is common in theSacramento Valley. hut does not occur inthe Eastern erra

There is no conclusive evidence thatdrinking water containing asbestos isharmful. Regulation of asbestos begai:when it was learned that workers exposedto asbestos through inhalation showed amarked increase in the incidence of lungcancer. as well as gastrointestinal tractcancer.

Because of the hazards of breathingasbestos fibers. in 1986 EPA proposed toban the use of asbestos roofing andflooring felts, vinyl asbestos floor tile,asbestos cement pipe and fittings, andasbestos clothing, and to phase out allother uses within ten years. Although theban would not affect asbestos already inplace, a specific federal law was passedrequiring that schools protect children andemployees from asbestos hazards.

While the ban has not become finalregarding asbestos cement (A-C) pipe.regulations for cutting or disposing of thepipe have already affected the waterindustry and suppliers are looking atalternatives, such as polyvinyl chloride(PVC) for use in water systems A-C pipehas been used in transmission anddistribution of water pipelines nationally forover fifty years:. Concern about possiblehealth effects of ingesting asbestos fibers--led EPA to set a proposed MCL of 7.1million long fibers per liter.

Conventional treatment includescoagulation and filtration, which canremove asbestos, and these techniquesare used in most major public systemsusing surface water.

Water-borne DiseasesThe clear, cold water of a mountain streamlooks appealing, but it is not necessarilysafe to drink Wilderness waters oftenharbor microscopic parasites that enter thestream through fecal contamination fromanimals, such as muskrats. beavers, andlarger animals. One such water-borneprotozoan is known as Giardia lamblia.and is a common problem in California sSierra waters. Giardiasis. the infectioncaused by Gardia causes nausea.clamps and diarrhea in humans EPA iscurrently setting standards to corer),Gorda Legionella and other entericviruses A similar diseaseCryptosporidiosis. was a known causeof diarrhea in many animal species butonly recently has been recognized ascause of intestinal disorders in humans It isnow suspected as the cause of mildgastroenteritis worldwioe. including casesof traveler s diarrhea, and one of thecauses of acute childhood diarrhea indeveloping countries It is also frequentlyreported to occur in animal handlersInfection with this organism is morecommon than previously suspected. LikeGiardia cysts. Cryptosporidium cystsappear to be highly resistant to the usuallevels of chlorination of potable watersupplies, and may have different filtrationrequirements because they are muchsmaller. Boiling the water can protect wellowners and backpackers from both thesediseasas Ozone may be more effectiveagainst these organisms than chlorine, butmost experts believe a combination oftreatment techniques is needed to kill orremove them.

Small communities cannot always affordelaborate treatment systems and some relyon a single method to meet healthrequirements. A combination of severalmethods is more effective for various kindsof organisms and metropolitan systemsusually have this kind of protection Theconcept of fecal contamination iscommonly misunderstood. When peoplehear this explanation for an outbreak ofdisease, they are often outraged andenvision their water supplies polluted withanimal feces. Bacteria can survive inmicroscopic particles of fecal matter. It isthese particles, that can only be seen bygreat magnification, that only rarely survivefiltration and end up in water supplies

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NitratesWhat About Nitrates? One of the leadingenvironmental problems worldwide isnitrogen pollution of ground water. theprimary concern is that valuable groundwater sources will be lost to futuregenerations because human activity iscausing the buildup of nitrates above whatthe environment can assimilate. (Somenatural denitnfication takes place in soiland ground water.) High nitrate levels arenot allowed in public drinking watersupplies, and are of greatest concern inprivate wells (which tend to be lessprotected against runoff and shallowgroundwater).

High levels of nitrates and nitrites in waterare suspected of causing cancer, but arethe known cause ofMethaemoglobinaemia, or Blue BabySyndrome. This is a sometimes fataldisease of infants (under three months)caused when nitrate reacts with the blood.making it unable to transport oxygen andcausing suffocation.

Nitrates in the environment come from theapplication of nitrogen fertilizers, livestock.and sources such as sewage treatmentplant discharges and septic tank leachfields.

Nitrogen is essential to plants, whichassimilate it in the form of ammonia andnitrate to produce proteins. Plants alsoreceive nitrogen from animal and humanwastes and from the atmosphere. Plantgrowth is enhanced and speeded up bythe addition of chemical fertilizers whichsupply other nutrients and supplementnitrates. Intensive farming has increasedthe amounts of chemical fertilizers appliedto the soil. California's farm organizationsare concerned about this problem and areworking with agricultural advisors andfarmers to help them achieve the properbalance of nitrogen for their crops withcutcausing ground water problems. Wellheadprotection programs can also help reducethe danger of future agricultural practicesendangering water supplies.

Many environmental groups favor banningchemical fertilizers altogether, pointing outthat even if all applications could bestopped now, the effects of past use ofthese fertilizers would still be felt 20 yearsfrom now because of the slow movement ofground water. Agricultural experts say thatfood shortages would result if chemicalfertilizers could not be used.

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EPA has set 10 parts per billion as itsmaximum contaminant level (MCL) fornitrates in drinking water.

Radioactive Materials InWater

EPA is now developing standards forradionuclides in water, but the biggestconcern seems to be about breathing theirdecay products. not drinking them.Radionuclides are radioactive forms ofbasic elements, and they can exist in manydifferent states.

Radon is the one we seem to be hearingthe most about. Radon gas begins as theelement uranium, which decays to radium.then to radon gas. Radon is a colorless.odorless, and apparently harmless gas. butits decay products, called radon"daughters", attach themselves to airborneparticles that can be inhaled into the lungs.Breathing high levels of these radon decayproducts is believed to be one of the majorcauses of lung cancer.

Radon gas can seep into houses fromunderlying geological formation or fromrock foundation materials, but it is alsosometimes in ground water and migrates tothe rest of the home environment when thewater is agitated by running from the tap orshower. It is the overall level in the homethat determines whether there is enough ofthe gas to be dangerous to health. Radonlevels can be reduced by simple measuresto improve ventilation in the home, likeventing basements or even merely openingwindows or doors to promote moreexchange with the outside air. Tightlyinsulated homes are the most likely to posea risk from high radon levels.

Elevated levels of radon have been foundprimarily in the eastern U.S., but also insome Western states. The CaliforniaDepartment of Health Services says thattesting so far in California has found only afew water utilities with fairly high radonlevels. One state source noted the highestlevels found in the state were in foothill andmountain areas east of Fresno and in SanBernardino County using ground waterfrom granite rock formations. Radon isunlikely to be present in surface watersupplies because in transport the waterhas been agitated and has probably lostany radon it may have had.

Conclusion

In this guide we have discussedmost of the health risks that arepossible if drinking water becomescontaminated. The threats fromwater-borne diseases are easy toassess because we know frornhuman experience the illnesses theycan cause, and how serious theycan be. Toxicologists can calculatedose-response curves for systemiceffects of toxins, such as lead. Formany kinds of contaminants there isa known threshold, and studies ordata to establish that nothinghappens below that level. Settingstandards for these substances isrelatively easy, because theinformation is available to determinesafe levels to protect human health.

For carcinogens the situation isdifferent. There is little humanevidence to tell us the amount of aknown or suspected carcinogen thatwill cause cancer. We also do notknow much about the possiblesynergistic effects where more thanone questionable substance may bepresent. In such cases, the totaleffect could be greater than the sumof the individual effects.

Toxicologists try to estimate thehealth effects of carcinogens, but 80to 90 percent of the date they workfrom is animal data,extrapolated to humans, and only 10to 20 percent is based on humanexperience. There are manyuncertainties; species as different asrats and rabbits are from humansmay not react the same way to asubstance. Some substances foundto cause cancer in mice do notcause cancer in rats, and theseanimals are much more alike thanhumans are to either.

Because there is so muchuncertainty about cancer causes,"worst case" assumptions are madewhen EPA sets standards for knownor suspected human carcinogens.They first assume that humans willreact the same as test animals, andthen assume that even one moleculeof a carcinogen will react with DNAto cause cancer.

Toxicologists use a formulato estimate the "no observable effectlevel," and then add a safety factorof 100 times or 1,000 times thatnumber, and set the limit that muchlower. For carcinogens, the drinkingwater standards are thus set at alevel believed low enough to causeno more than one cancer in onemillion people if ingested over alifetime. Most experts agree that thisapproach tends to overestimate thecancer risk, but it does offerunquestionably strong public healthprotection.

To help people assess relative risks,the health risks are usually stateJ interms of the expected number ofhealth effects resulting from a givenlevel of exposure. One way toevaluate a particular risk is tocompare it with the probable numberof health effects or deaths from otheiknown causes. However, the samebasic information can be presentedin different ways. The way it ispresented greatly influences ourperception of risk.

Even the most scientific andunbiased risk assessment may stillhave little impact on our reactions toany risk connected with publicdrinking water.

Scientists can prove that werun far greater risks from smokinga cigarette or eating a foodcontaining natural carcinogens thanwe are ever exposed to from publicdrinking water. They can point outthat we consciously choose to takemore dangerous health risks everyday, in many of our activities.

These arguments have little or noeffect on the level of safety the publicdemands from drinking water. Weare much more willing to accept avoluntary risk than any risk weperceive as imposed upon us. Riskassessment experts say we willspend 100 times as much toeliminate an involuntary risk as avoluntary one. Any risk connectedwith a public water supply is seen asan involuntary risk, and thereforeunacceptable, no matter how low. .

This attitude may change as more isknown about the degree of healtheffects possible from toxicsubstances in given amounts inwater, so that unfounded fears canbe dispelled and actual health effectscan be reliably estimated. Until then,consumers will probably continue todemand increasingly strictregulations for drinking water. It isonly through extensive research andfactual evidence that this trend willchange.

WATER FACTSHOW MUCH WATER DO WE USE?

Takini a Bath orShower

Watsring theLawn and Yard

Washing the Dishosby Machine/Hand

Washing Clothes

Washing the Car

Brushing Your

Teeth

Cookini

Drinking

Rushing the

Toilet (once)

leaking Toilet

(Pe 41Y)

ANSWER 9-12 GAL1DNS

HOW MUCH WATER DOES IT TAKE

TO PRODUCE ONE SERVING OF-.

I re'l LETTUCE (1 cup)

TOMATO CATSUP (1oz)

WHITE SUGAR (Iiis)

WHOLE WHEAT BREAD (1 slice)

TOMATOES (4.3oz)

WHITE BREAD (1 slice)

FRESH BROCCOLI (2.7oz)

TOMATO PASTE (24z)

TOMATO SAUCE (4o4

ORANGES (4.6oz)

BROWN RICE (loz)WHITE RICE (1oz)

PASTA (2o4

CANTALOUPE (8oz)

BUTTER (0.36oz)

MILK (8 oz)

ORANGE JUICE (1 cup)

CHEESE (1oz)

TOFU (1/2 cup)

EGG (1)

ALMONDS (1oz)

PLAIN YOGURT (1 cup)

CHICKEN (86z)

HAMBURGER (4oz)

STEAK (86z)

PULL

0ANSWER

HOW MUCH OF ME EAKII'S WATERSUPPLY IS:

SALT WATER

FRESH WATER

GROUND WATER

LAKES & STREAMS

GLACIERS & ICECAPS

WATER VAPOR IN ME ATMOSPHERE 6

CALIFORNIA WATER SUPPLY QUIZHOW MUCH:

a

FACT:

Water runs off mouftiains in theform of rain or snowmeit?

Water can California's reservoirs store?

Ground water do we use?

More ground water do we use than

goes back into the ground?

Water do we get from theColorado River?

Fresh water flows from the

Delta irrto the ocean (on average)?

Water does the federal

Central Valley Project deliver?

Water is delivered by the

State Water Project?

Water de state experts estimate we

could be short by the year 2010?

L/LJ MILLION ACRE-FEET/YEAR

One acre-foot equals approximately

325,900 gallons, enough to fill a

football field to a depth of one foot

or to supply the water needs of a

household of up to five for a ear.

FOR MORE FACTS, CONTACT:

Water Education Foundation717 K Street, Suite 517 Sacramento, CA 95814 (916) 444-6240

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TITLE Level. INSTITUTION - Education Resources Information ...

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