OnTap · OnTap Summer 1996 1 OnTap Drinking Water News For America’s Small Communities Summer...

OnTap Summer 1996 1

OnTapDrinking Water News For America’s Small Communities

Summer 1996Volume 5, Issue 2

On Tap is apublication of theNational Drinking

Water Clearinghouse,sponsored by the

Rural Utilities Service.

An Interview with Jill Long Thompson

What’s the word onwater at the USDA?

Editor’s note: With passage of the Farm Billin April, the U.S. Department of Agriculture’sRural Economic and Community Development(RECD) simplifies its name to Rural Development.However, only the name will change. RuralDevelopment, defined as a mission area, will notchange as a result of the bill. The terms RuralDevelopment and RECD are used interchangeablyin this article.

National Drinking Water ClearinghouseProgram Coordinator Sanjay Saxena, WaterSense Editor Laurie Klappauf, and On Tap EditorHarriet Emerson interviewed U.S. Department ofAgriculture Under Secretary for Rural Develop-ment, Jill Long Thompson. Discussion centeredon the Water 2000 initiative, financial issues,including the impact of congressional budgetcuts and the Farm Bill, and the department’svision for the next century.

Rural Economic and Community Development(RECD), now Rural Development, includes threeagencies that aid rural America: Rural UtilitiesService (RUS), Rural Business–CooperativeService (RBS), and Rural Housing Service.

RUS, which funds the National DrinkingWater Clearinghouse (NDWC), also providesmoney for water and waste disposal loans andgrants, technical assistance and training, emergencycommunity water assistance, rural water circuitrider technical assistance, rural electric and tele-phone loans, and distance learning and medicallink grants.

An extensive network of state and districtRural Development offices administer RUSWater and Wastewater Loan Programs.

A 1995 U.S. Gen-eral Accounting Office(GAO) report statesthat the RUS Waterand Wastewater LoanProgram is “nowthe major source offederal funds targetedContinued on page 9

Search for

Clean Water

Continues,

page 6

Jill Long Thompson, Under Secretaryfor the U.S. Department of Agriculture’sRural Development

water varies in quality and, like many smalltowns, Littleton has faced major decisions abouthow to remain in compliance with the SafeDrinking Water Act. In 1994, it made the some-what unusual choice of installing a photovoltaicchlorine dioxide disinfection system.

Littleton Water and Light Department, munici-pally owned by the Town of Littleton, suppliespower and water to 3,400 electric customers. Itboasts one of the lowest electric utility rates inNew England with rates almost 45 percent lowerthan those of commercial customers subscribingto the state’s largest utilities.

The town’s electric power is purchasedwholesale from New England Power Company(NEPCO) which generates hydroelectric power

Town Treats Water with Chlorine Dioxideby Harriet EmersonOn Tap Editor

Littleton, New Hampshire, has been a small,self-reliant town for more than 200 years—weathering wars, recessions, and depressions.Solvent and stable, Littleton was establishedduring the 1770s by settlers who headed northfrom Boston. It is one of several small townsnestled in New England’s scenic White Mountainregion near the slopes of Mt. Washington. Hometo almost 6,000, it’s the kind of place wherequality of life takes precedence over high incomeand decisions are still made in town meetings.

The town’s drinking water flows from an unfil-tered surface water supply in the well protectedWhite Mountain National Forest watershed. Surface Continued on page 12

2 OnTap Summer 1996

R E S O U R C E S

NA

TIO

NAL DRINKING WA

TE

R

C

LEAR IN GHOUSE

Volume 5, Issue 2Summmer 1996

Sponsored byRural Utilities

Service

AdministratorWally B. Beyer

Loan SpecialistDonna Roderick

Established in 1991 at WestVirginia University, the NationalDrinking Water Clearinghouse

is funded by the Water andWaste Disposal Division of the

Rural Utilities Service.

National Drinking WaterClearinghouse

Manager, WVU EnvironmentalServices and Training Division

John L. Mori, Ph.D.

Program CoordinatorSanjay Saxena

Technical ServicesCoordinator

David Pask, P. Eng.

PublicationsSupervisorJill A. Ross

PromotionsSupervisorDiana Knott

Managing EditorHarriet Emerson

Staff WritersP.J. Cameon

Lauretta GalbraithKathy Jesperson

Graphic DesignerEric Merrill

On Tap is a free publication,produced four times a year(February, May, August, and

November). Articles, letters tothe editor, news items, photo-

graphs, or other materialssubmitted for publication are

welcome. Please addresscorrespondence to:

Editor, On Tap, NDWCWest Virginia University

P.O. Box 6064Morgantown, WV 26506

(800) 624-8301

Permission to quote from orreproduce articles in this

publication is granted whendue acknowledgment is given.

Please send a copy of thepublication in which informationwas used to the On Tap editor

at the address above.

The contents of this publicationdo not necessarily reflect the

views and policies of the RuralUtilities Service, nor doesmention of trade names or

commercial products constituteendorsement or

recommendation for use.ISSN 1061-9291

OnTap

On Tap Looks at Disinfection, Funding

• intermediate rate: 4.875 percent (down.125 percent from the previous quarter);

• market rate: 5.375 percent (down .125percent from the previous quarter).RUS loans are administered through local

or state Rural Development offices, recentlyknown as Rural Economic and CommunityDevelopment offices. These offices canprovide specific information concerning RUSloans and applications.

For the number of your nearest RuralDevelopment office, contact the National Drink-ing Water Clearinghouse at (800) 624-8301.

For the second consecutive quarter, twoof the three interest rates for Rural UtilitiesService (RUS) water and waste disposalloans have decreased. One interest rateis unchanged.

RUS issues loans at one of three interestrates, according to community qualificationcriteria. The rates for the third quarter ofFiscal Year 1996 apply to all loans issuedfrom April 1 through June 30, 1996. Theserates are:

• poverty line rate: 4.500 percent (un-changed from the previous quarter);

RUS Loan Rates Decrease Again

This On Tap overflows with information,much of which deals with disinfection, in general,and chlorination, in particular. We feature a lookat why and how a small New Hampshire townchose to install a solar-powered chlorine dioxidedisinfection system. (See page 1.) Readers oftenindicate that case studies are a good way to learn,and Ed Betz, superintendent for Littleton Waterand Light Department, provides costs, details, andtechnical information on its system. Incidentally, Ilearned about Littleton’s new chlorination systemon the town’s home page on the World Wide Web.

Federal loans, grants, and technical assistanceare an integral part of the infrastructure plan formany small towns. Three National DrinkingWater Clearinghouse (NDWC) staff members hadthe good fortune to discuss funding and visionwith Jill Long Thompson, under secretary to theU.S. Department of Agriculture’s Rural Economicand Community Development, now called RuralDevelopment. (See page 1.)

Mohamed Lahlou, NDWC technical assis-tance specialist, and Eric Merrill, NDWCgraphic artist, are the primary forces behindthe fact sheet or “Tech Brief” in the centerpages of this issue. The topic is disinfection.Our next Tech Brief features filtration.

And in the Q&A (see pages 16–17) ArjitaSharma, NDWC staffresearcher, answers thequestion posed by severalreaders: What are disin-fection by-products?We hope this providesanswers to some ofthose questions.

One On Tap reader suggested that we write ahistory of disease organisms and water. We likedthat idea, and the first of this three-part history byStaff Writer Kathy Jesperson begins on page 6.This series should provide a good backgroundfor educators. But whatever your interest, thereare some fascinating elements in the history ofdrinking water.

On the facing page are the results of our OnTap/NDWC survey. There were so many requestsfor information beyond the scope of drinkingwater, that we’re including a page in this issuelisting newsletters that our office publishes. Thesenewsletters contain useful information on septicsystems, solid waste, environmental training, andthe financial side of the water business. All of thepublications are free (see page 19).

On Tap will continue to provide you with thedrinking water information you want and need. Ifyou have questions, comments or suggestions,call (800) 624-8301, or e-mail me at

[email protected]. If you havetechnical questions, call our toll-freenumber and ask to speak with a technicalassistant. Also, if you are online, technicalquestions can be addressed to Lahlou [email protected] or to

Sharma at [email protected].

Harriet EmersonOn Tap Editor

OnTap Summer 1996 3

N E W S & N O T E SN E W S & N O T E S

On Tap Survey Results Are AnnouncedWe are still receiving occasional responses to

the On Tap readership survey; however, withapproximately 450 responses in, there is sufficientinformation to report.

On Tap appears to have a strong readershipamong individuals charged with the task ofkeeping water systems and communities running.Of those who responded, almost 12 percent arewater plant operators; 31 percent are local govern-ment officials; 12 percent are state governmentofficials; and 6 percent are federal governmentofficials. Thirteen percent of respondents areeither engineers or consultants and 9 percentare educators.

On Tap provides information on the drinkingwater needs of communities with fewer than10,000 people, and 31 percent of all respondentslive in areas with 10,000 or fewer people: 14percent live in areas with populations between3,301 and 9,999; another 13 percent live in areaswith 501 to 3,300 people; and 4 percent live inareas with populations of fewer than 500.Twenty-three percent of respondents stated thatthey live in areas with populations between10,000 and 49,000. A surprising 42 percentof respondents live in areas with populationsgreater than 50,000.

Almost half of the respondents (42 percent)said that they pass On Tap along to others afterreading, which indicates that our readership isbroader than our mailing list. Another 56 percentsaid they save On Tap for reference.

Most respondents appear pleased with thecaliber of our publication. Content and overallusefulness ranked highest with 83 percent and78 percent, respectively, rating the publicationgood or excellent.

Almost everyone responding found thelanguage and type size easy to read: 83 percentfound the language just right although 11 percentfeel the language we use should be more technical.

When asked which articles are most likely tobe read, 70 percent read technical articles, withregulatory articles (68 percent) running a closesecond. Short news articles have high readership(62 percent), as do articles about system operationand maintenance (55 percent). Less than a third(26 percent)—the lowest rating—went to inter-views with government officials. We’re trying toimprove and have switched to a feature articleformat rather than publishing strictly interviewquestions and answers. (See interview with JillLong Thompson on page 1.)

A little more than a third (36 percent) ofrespondents said they read the products page,which may explain why only a quarter of

respondents have ordered products advertised inOn Tap or have called our toll-free 800 numberfor technical assistance. However, of those whodid call for information or to order products, therate of satisfaction was close to 100 percent.

Approximately a third of the 460 individualswho answered the On Tap survey includedresponses to the question: What additional topicswould you like to see addressed in On Tap and/orwhat do you most want information about? Pleasebe specific.

The responses to this open-ended question fellinto five primary categories: water treatment andwater systems; source water, watershed protectionand water conservation; regulations; finance; andeducation.

By far, the largest number of requests were foradditional information on various types of watersystems and how to treat water. (See RESULTSarticle on page 4.) Subsets under this headingincluded requests for information on individualwells and home treatment—point-of-use andpoint-of-entry—devices. Others specificallyrequested information on microbes and new orbest available technology.

There were many requests for information onregulations, including explanations ofnew regulations and changesin existing ones.A number ofpeople specifi-cally requestedupdates on the SafeDrinking Water Act.

More than a dozenreaders requested informationon loans, grants, and fundingsources, including financing through sourcesother than the federal government, and othersrequested information on septic systems. (Seepage 19 for publications on these subjects.)

A number of very good comments, of course,did not fit into the primary categories outlinedabove. Some contain questions that can be usedfor the Q&A section. Many suggestions willmake good topics for articles.

We do receive frequent inquiries as to whetheryou can make copies of articles and distributethem. You can. If you use the information in anewsletter, we request that you give the NationalDrinking Water Clearinghouse credit and sendus a copy.

Thanks for your feedback. We look forward toimproving our newsletter to best serve you.

4 OnTap Summer 1996


Cholera Is Caused by a Bacteriumsimply with a solution of oral rehydration salts(ORS) available from most pharmacies.

If you travel to an area where there is choleraand develop diarrhea, immediately seek treatmentfrom a trained health professional and begindrinking potable water and other non-sweetenedfluids. The WHO recommends that travelers carryORS with them. Severely dehydrated patientsmay need to be treated with intravenous fluidsand antibiotics; however, this is usually notnecessary or recommended.

Are cholera outbreaks still a threat?Cholera is present in many countries. Out-

breaks can occur sporadically in any part of theworld where water supplies, sanitation, foodsafety, and hygiene practices are inadequate.Inhabitants of overpopulated communities withpoor sanitation and unsafe drinking water suppliesare most frequently affected.

For more information on cholera and safetyfacts for travelers, visit the WHO’s home page athttp://cdrwww.who.ch/default.htm.

This issue of On Tap includes the first of a three-part series on the history of water treatment andwaterborne diseaseson page 6. The second install-ment will explore cholera’s impact on humanity.

Water Fact

Polluted waterleads, in one way or

another, to thedeath of some 25

million peopleannually.

—EnvironmentalEngineering News,

HeritageEnvironmentalService, Inc.,

Purdue University

New Version of RESULTS Is AnnouncedThe National Drinking Water Clearinghouse

(NDWC) is pleased to announce the new versionof its drinking water treatment technologiesdatabase.

Called the Registry of Equipment Suppliersof Treatment Technologies for Small Systems,or “RESULTS,” the database serves as an initialreference source for small communities, regulators,and others seeking information about appropriatedrinking water technologies.

“Regulators and communities may not knowwhat technologies are successfully being used inneighboring states or regions with similar waterproblems,” says NDWC Program CoordinatorSanjay Saxena, adding that RESULTS was devel-oped to facilitate exchange of information abouttechnologies in use around the country.

RESULTS 2.0 is easy to use and was developedafter obtaining input from several relevant agen-cies and organizations. Those offering suggestionsincluded representatives of the U.S. Departmentof Agriculture’s Rural Utilities Service, U.S.Environmental Protection Agency, Associationof State Drinking Water Administrators, andWater and Wastewater Equipment ManufacturersAssociation.

Information about nearly 175 small drinkingwater systems and the manufacturers who pro-vided their treatment equipment is currentlyincluded in RESULTS 2.0, with more datacontinually being sought and received. Searchesof the database can be conducted by:

• state where the system is in place,• drinking water contaminants removed,• technology employed, and/or• equipment vendor.RESULTS is available to the public by

accessing the NDWC’s toll-free computer bulletinboard system—the Drinking Water InformationExchange—at (800) 932-7459, or it may bepurchased on computer disk from the NDWCfor $5, plus postage. Both DOS and Macintoshversions are available and require approximately1.5

megabytes of memory and 3 megabytes of

hard drive space. Those without computer accessmay call the NDWC and ask a technical assistantto perform a specific search for them.

For more information about accessing orsubmitting information to RESULTS, contactNDWC Technical Assistance Specialist MohamedLahlou at (800) 624-8301. You can e-mail him [email protected].

Editor’s note: An article in the Spring 1996On Tap, “Ecuador Suffers Cholera Outbreak,”incorrectly referred to cholera as a virus.Thanks to several observant readers, NationalDrinking Water Clearinghouse staff quicklylearned of the error.

Cholera is an acute diarrheal disease causedby the bacterium Vibrio cholerae. A person canbecome infected by drinking water or eating foodcontaminated by the bacterium. Common sourcesof infection are raw or poorly cooked seafood,raw fruit and vegetables, and other foods contami-nated during preparation or storage.

According to the World Health Organization(WHO), most episodes of cholera are mild andpeople may have no symptoms or only milddiarrhea. Others, however, develop extremediarrhea and vomiting. The loss of large amountsof fluid can rapidly lead to severe dehydrationcausing death—sometimes within three to fourhours if not adequately treated.

How is the illness treated?Early rehydration—replacement of fluids—

can save the lives of nearly all patients with chol-era. Most patients can be rehydrated quickly and

OnTap Summer 1996 5


New Technology Makes Work Less Like Work

Jeffrey Mann, an employee of the E.H. WACHScompany, (right) demonstrates a computerizedvalve operating system for Morgantown UtilityBoard employees Robbie Johnson (left) andKenny Summers (center).

Pulled shoulder muscles and strained backsmay be a thing of the past for Morgantown Util-ity Board (MUB) employees. The MUB, inMorgantown, West Virginia, recently purchaseda computerized valve operating system.

Robbie Johnson and Kenny Summers work asthe city’s valve operating team,which requires them to openand close valves on the city’swater mains on a regularbasis—ensuring their properoperation in emergencies.

“Everyone should knowhow important a valve operatingprogram is,” says David Pask,National Drinking WaterClearinghouse’s technicalservices coordinator. “If propervalve operation is ensured,when a section of the mainneeds to be shut off for repairsor alterations, it may only benecessary to shut off two orthree valves. One faulty valvecould mean the closure of four or five othervalves, causing a much larger area of the commu-nity to be without water.”

A good program is especially important if autility is working with older distribution equip-ment. For example, many of the valves aroundMorgantown have been in place since 1928.Corrosion and debris built up in the valves oftenmake operation almost impossible. In this situation,a little help is essential.

“This equipment is going to make our jobs alot easier,” says Johnson, recalling last year’slong hot summer of manual valve operation inwhich the duo used a gate key and good old-fashioned strength and endurance to accomplishtheir job.

Initial investmentof the equipment isapproximately $12,500for the truck-mountedvalve operating system,$1,500 for a manualvalve operation unit,and varying costsfor outfitting theutility’s truck.

Expensive at first,but worth it in thelong run, say Johnsonand Summers. Havingthe equipment willallow them to do morework in less time withmuch less physical

exertion—keeping them on the job and not athome recovering from muscle strains.

Pask comments that although the equipmentcost may be high for a very small town, it’s aninvestment that several towns might consider as ajoint venture.

For more information, call E.H. WACHScompany at (800) 323-8185.

The U.S. Environmental Protection Agency’s(EPA) American Indian Program has seen excitingadvances in the last two years.

Nationally, EPA Administrator Carol Brownerappointed Terry Williams to head the AmericanIndian Environmental Office (AIEO), which beganoperations in October 1994. Williams came to theprogram from the Northwest’s Tulalip Tribe.

For the first time, EPA has a central officeto coordinate all tribal environmental programdevelopment and implementation.

Regionally, communications among EPA andthe tribes have helped the program assist tribeseither financially or directly. For example, tribesmay apply for grant assistance through the IndianEnvironmental General Assistance Program,which provides funds for federally recognizedtribal governments and tribal consortia. Fundsmay be used for planning, developing, and estab-lishing environmental management programs.

Tribes may apply for these grant fundsthrough EPA regional offices. New grants willbe for a minimum of $75,000. The project periodfor general assistance grants can be from one tofour years; however, the grantee may apply foradditional time if it is needed.

One project developed and funded throughEPA’s American Indian Program is the RuralAlaska Sanitation Initiative. This program focuseson improving sanitation conditions in remoteareas of the state.

Tribes may receive more information aboutgrant funding through regional EPA offices. Formore information about EPA’s American IndianProgram, call the AIEO at (202) 260-7939. Forthe number of your regional EPA office, callthe National Drinking Water Clearinghouse at(800) 624-8301.

American Indian Program Builds Momentum

6 OnTap Summer 1996

Search for Clean Water Continues

E D U C A T I O NE D U C A T I O N

“And the rest of the actsof Hezekiah, and all hismight, and how hemade a pool, and aconduit, and broughtwater into the city, arethey not written in thebook of the chroniclesof the kings of Judah?”II Kings 20:20

by Kathy JespersonNDWC Staff Writer

Editor’s note: This is the first installment of athree-part series on the history of water treatmentand waterborne diseases. The subject was sug-gested by a respondent to On Tap’s readershipsurvey. In this first article, we’ll look at our questfor clean drinking water from ancient times to thepresent, using various water treatment methods.While there is no way we can touch on everywater treatment known to humankind, we canillustrate that humans have always had a thirstfor clean water.

Long before humans learned to rub two stickstogether to make fire or took a hammer and chisel

in hand to carve out the first wheel, theythirsted for pure drinking water. As we findourselves in awe of the latest contaminanttreatment methods and detection devices, it iseasy to forget that the desire for pure drinking

water is not a modern phenomenon. Evidencefrom almost all historical periods suggests that

people took measures to ensure a fresh drinkof water.

But sometimes that drink came with morethan its thirst quenching qualities. Earlyhumans thought that the taste of the water

determined its purity, and they did not considerthat even the best tasting water could containdisease-causing organisms. We know now thatjust because water tastes good, it is not necessarilysafe to drink. However, the efforts of these watertreatment pioneers were not in vain. It wasthrough their trials and errors that we now knowhow to make water safe to drink.

Centuries Old Quest ContinuesAccording to the American Water Works

Association’s (AWWA) two-volume 1981 text-book, The Quest for Pure Water: The History ofWater Purification from the Earliest Records tothe Twentieth Century by M.N. Baker andMichael Taras, “Man has persistently pursued‘pure’ water for thousands of years.” Theyspeculated that this “quest” for pure water musthave begun in prehistoric times. But the earliestwater treatment records come from Sanskritwritings and Egyptian inscriptions.

The Sus’ruta Samhita, Sanskrit writings aboutmedical concerns, dates from approximately 2000B.C. and offers evidence that water treatment maywell be as ancient as humans are. The writingsdeclare that “impure water should be purified bybeing boiled over a fire, or being heated in thesun, or by dipping a heated iron into it, or it may

be purified by filtration through sand and coarsegravel and then allowed to cool.” Other purificationmethods included the use of a kind of stone,known as “Gomedaka,” and the seed of Strychnospotatorum.

In 1905, Francis Evelyn Place, who studiedSanskrit medical lore, wrote, “It is good to keepwater in copper vessels, to expose it to sunlight,and filter through charcoal.” He was referencingthe Sanskrit Ousruta Sanghita, which also datesfrom about 2000 B.C.

Tomb Reveals First Clarifying DevicePictures of the earliest known clarifying

apparatus were first excavated from the wallsof 15th and 13th century B.C. Egyptian tombs(see illustration on facing page). The device waspictured in the tomb of Amenophis II and later inthe tomb of Rameses II. The ancient Egyptianoperators allowed impurities to settle out of theliquid, siphoned off the clarified fluid using wicksiphons and, finally, stored it for later use.

Bible Refers to Water QualityThe ancient Hebrews were also concerned

with clean drinking water. The King James Versionof the Holy Bible records examples that date toapproximately the ninth century B.C. In Exodus15:22–27, when Moses and the Israelites cameupon Marah, they found that the waters therewere bitter. The text states that the Lord showedMoses a tree, and instructed him to cast it into thewater. He did so, and the water was sweetened.

While we don’t know exactly what kind oftree Moses used to sweeten the water, later in the15th chapter of Exodus, the wanderers camp inwhat might be a desert oasis—which has threewells and is surrounded by palm trees.

Later in the Old Testament—II Kings 2:19–22—the residents of Jericho confided to Elishathat their city was a pleasant place to live, butthe water was “naught.” Elisha went to the city’ssprings, where he cast “salt” into water. Thewaters were thus healed “unto this day.”

Medicine Man Explores Water TreatmentHippocrates, known as the father of medicine,

who lived from 460–354 B.C., wrote the firsttreatise on public hygiene. In Air, Water, andPlaces, the medicine man noted that water differedin quality, such as in taste and weight. While hismain concern was with finding the most healthfulsource of water, he did mention how water couldbe purified.

Using what later became known as “Hippo-crates’ sleeve,” which was a cloth bag, heContinued on next page

OnTap Summer 1996 7


This ancient Egyptianclarifying device wasfound pictured on thewall of the tomb ofAmenophis II at Thebes.The inscription wascarved in 1450 B.C.

Reprinted from The Quest forPure Water: The History ofthe Twentieth Century, bypermission. Copyright ©1981, American Water WorksAssociation.

Continued from previous pageinstructed his followers to strain rain water afterit had been boiled. Without this treatment,Hippocrates warned that the water would have abad smell and cause hoarseness.

Other water treatment methods included adrinking cup invented by a ninth century B.C.Spartan lawgiver. The cup was designed to hidebadly colored water from its user, causing the mudto stick to its sides. Some of the more credibleearly water treatment methods included boilingwater before transporting it to war zones andfiltering it through wick siphons.

The Greeks and Romans are well known fortheir elaborate water systems. These early watertreatment professionals used a variety of methodsto control taste and odor problems in their watersupplies. For example, Diophanes of the firstcentury B.C. advised putting macerated laurelinto rainwater. Later, in the first century A.D.,Paxamus proposed that bruised coral or poundedbarley, in a bag, be immersed in bad tasting water.

The eighth century A.D. Arabian alchemist,Gerber, described various stills for purifyingwater that used wick siphons—a method thatrequired a fibrous cord that would siphon waterfrom one vessel to another.

Desalination Experiments BeginIn 1627 A Natural History of Ten Centuries

was complied by Sir Francis Bacon. This workrecorded 10 experiments that dealt with waterpurification. In it Bacon explained some of hisideas about desalination. He believed that seawater could be purified if it were percolatedthrough sand because he had read that anexperimenter had been successful at purifyingsea water by passing it through 20 vessels.

Armed with this information, Bacon concludedthat “what man could not accomplish, naturemight.” He surmised that by digging a hole nearthe sea shore, water passing through the sandwould be naturally purified. Pointing out that thewater passed downward through the 20 vessels inthe experiment he had read about, Bacon said hisseaside experiment would cause it to pass upward.Presumably, salt particles were heavier thanwater, making it more difficult for them tomove in the upward direction, and they wouldconsequently be filtered out by the sand. If onlyhe had been right.

Filtration Is IllustratedThe 17th century A.D. also saw the first

known illustration of sand filters. The Italianphysician Lucas Antonius Portius wrote theSoldier’s Vade Mecum in 1685, which details a

multiple sand filtration method. In this illustration,Portius described three pairs of sand filters—eachpair consisting of a downward-flow filter and anupward-flow filter. Water entered the system’ssettling compartment through a perforated platethat strained the water.

Once the water had settled, it flowed from thetop of the compartment through two funnels anddown through the first filter. It then moved outthrough oblong openings in the bottom of thesecond filter and up through the second filter.The water continued in this same general patternthrough the other two sets of filters.

He also described how pebbles had beenplaced near “the funnels of each partition,” andthat smaller pebbles and larger sand grains pro-duced the best water. Portius further described hisfiltration plan as being an imitation of nature’smethod of passing water through the “bowels ofthe earth.”

Every Household Deserves Clean WaterFiltration was becoming the water treatment

method of choice for many communities.And town officials began tobecome concernedwith supplyingclean water toeveryone, wroteBaker and Taras inQuest for PureWater. Around1703, the Parisianscientist La Hirepresented a planto the French Acad-emy of Sciences,proposing that everyhousehold have asand filter and rainwater cistern.

His plan included an elevated, covered cistern,which would prevent freezing and keep out light,thus preventing the surface from growing a“greenish kind of moss.” The rainwater shouldthen be passed through river sand and storedunderground.

La Hire believed that rainwater treated usingthis method was the best water because it had notbeen “mixed with the salt of the earth as springwaters usually are.” And he believed that it couldbe stored for years, always staying fresh.

Municipal Water Treatment BeginsApproximately 100 years after La Hire proposed

his rainwater filtration method, the first municipalwater treatment plant was installed in Paisley,Continued on page 8

8 OnTap Summer 1996

Search for Clean Water Continuesmade, according to the AWWA’s Water QualityTreatment Handbook. In mid-19th century London,town officials noticed a decrease in cholera deathsduring the 1849 and 1853 epidemics where slowsand filters had been installed.

But even more convincing evidence emergedwhen John Snow was able to trace multiplecholera deaths to a single pump in Soho, England,which had become contaminated by a nearbyleaking sewer, wrote N.M. Blake in Water for theCities. An interesting note to this story is that theusers of this Broad Street well pump came fromother parts of the town because they preferredthe taste of the water. This is some of the firstevidence that taste and clarity do not alwaysindicate safe water supplies.

Blake wrote that shortly after town officialsrealized contaminated water had been the culpritin these disease outbreaks, London enacted theMetropolitan Water Act of 1852, which requiredthe filtration of all water supplied to the Londonarea. This legislation is one of the first instancesof governmental regulation of a water supply.

New Concerns EmergeThe 19th century also brought the Industrial

Revolution, and a whole new perspective onwater treatment. Chemicals—and not justmicrobials—now polluted the world’s watersupplies. New, much more sophisticated watertreatment methods would now be called for,raising the question, “Once we’ve polluted thewater—how do we purify it?”

ReferencesThe history of water treatment and water-

borne disease will continue in the next edition ofOn Tap. To learn more about the history of watertreatment and waterborne disease, please checkthe following references:

American Water Works Association (AWWA). 1971.Water Quality and Treatment: A Handbook ofPublic Water Supply. Denver: AWWA.

Baker, M.N. and Taras, Michael J. 1981. The Quest forPure Water: The History of the Twentieth Century,Volume 1 and 2. Denver: AWWA.

Blake, Nelson M. 1956. Water for the Cities. Syracuse:Syracuse University Press.

Bruce, F.E. 1958. History of Technology, Volume 5.Oxford: Claredon Press.

Scotland. This 1804 treatment plant consisted ofconcentric sand and gravel filters, and its distribu-tion system consisted of a horse and cart.

Three years later, Glasgow, Scotland, wasone of the first cities to pipe filtered water toconsumers. By 1827, slow sand filters designedby Robert Thom were put into use at Greenock,Scotland. Similar systems designed by JamesSimpson were completed in London in 1829.Thom’s filters were cleaned by backwash, whileSimpson’s required scraping. The Simpsondesign eventually became the English modelthroughout the world.

Throughout 19th century in London, slowsand filtration was the water treatment method ofchoice. However, the large area of land requiredto support their use caused some concern. Thesand beds, which were two- to three-feet thick,covered acres of ground. Cleaning the beds wasusually accomplished using a shovel and vigorousphysical effort.

The large area of land required also interferedwith land needs for city growth, wrote F.E. Brucein the History of Technology. For example, thecombined water treatment plants of 1849 Londontreated 44.4 million gallons of water a day. At aflow rate of three gallons per hour per squarefoot, 12 acres of land would be required to producethe needed water. By 1901, London required 215million gallons per day of clean water. Obviously,slow sand filters could not keep up with thisexpanding city.

Because the need for clean water was growingquickly, rapid sand filtration was developed in theU.S. in the 1880s, wrote Baker and Taras. Thetwo main design elements of Thom’s filter wereincorporated into this new design—the falsebottom and reverse-flow wash—becomingstandard features of these filters.

Rapid sand filters used water jets or backwashesto clean the filter media and mechanical agitatorsto loosen debris. Treatment capacity was greatlyincreased using these new filters and land arearequirements were greatly reduced, noted Bakerand Taras. However, rapid sand filtration requiredpretreatments, such as coagulation and settling, toreduce the sediment load to the filter. Treatmentto improve taste and odor of the water wasachieved by the use of charcoal filtration, althoughit was not widely used at first because it wasthought to be unfeasible for large supplies.

Links to Health FoundIt was also around this time that the first cor-

relation between water quality and health were

Continued from page 7


“It is good to keep

water in copper

vessels, to expose

it to sunlight, and

filter through

charcoal.”

Sanskrit OusrutaSanghita,

approximately2000 B.C.

OnTap Summer 1996 9

C O V E R S T O R YC O V E R S T O R Y

What’s the word on water at the USDA?Continued from page 1 down. She said they have not changed their fund-

ing priorities and try to process applications asrapidly as they can.

Currently they are working on a proposedregulation change that would streamline the RUSwater and waste application process. “Our stateRural Development staffs are working with otheragencies, such as the U.S. Environmental ProtectionAgency [EPA], to coordinate and redesign theapplication process, and also to synchronize thefunding schedules so that the grant awards andloans are made at the same time across agencies.In addition to that, we’re always looking for waysto cut red tape—to standardize and simplify.”

USDA Is Committed to Water 2000Long Thompson stressed that the USDA is

working with other state and federal fundingagencies to reach as many communities as possible.

“We still have about a half a million homes inrural America that don’t have any running water,”she said. “And then, we have several millionother homes that have water supplies that do notmeet EPA standards. So we have a real challengeto try to meet the President’s initiative—the Water2000 initiative—of making sure that every homehas running water by the time we go into thenext century.”

Long Thompson said the Clinton administrationis committed to increasing the amount of moneyavailable to communities—those targeted byWater 2000 as well as other communities in need.

On March 19, USDA Secretary Dan Glickmanunveiled the administration’s FY97 budget, whichstresses priorities for rural development, research,conservation, and trade. According to a USDApress release, the budget proposes $56 billion inoutlays for FY97, including $9.3 billion for loansand grants for rural housing, utilities, and businessprograms—a $2 billion increase from the 1996level. However, these are proposals and subject toa rigorous review process—and possible reduc-tions—in their journey through Congress.

“The President’s budget proposal for FY97would support a water and waste disposal loanprogram of $800 million, compared with $547million in 1996, and a grant program of $590million versus $365 million for ’96,” LongThompson said.

“We actually have a number of priorities, butcertainly those communities that do not haverunning water are a very high priority for us inthe Rural Utilities Service. And these are areas inthe country that have been identified in our Water2000 Needs Assessment,” Long Thompson said.“The Rural Development directors for the states

to water and sewer projects in rural areas.”According to the report, Rural Development:USDA’s Approach To Funding Water and SewerProjects, the U.S. Department of Agriculture(USDA) has provided $28 billion in loans andgrants to fund almost 17,000 water and sewerprojects in the last 30 years. These projects havebenefited more than 12,500 communities.

The greatest challenges to federal agenciesand federally funded programs, including RUS,are massive budget cuts. Safe drinking water andsanitary waste systems are essential to the eco-nomic and physical health of all communities.Agencies are struggling to stretch funds so theycan meet goals to which they are committed andcontinue services at levels that meet public needs.

“As you know,” Long Thompson began,“there was a 31 percent reduction in the water andwaste loan and grant funds for fiscal year [FY]’96, and that does have a major impact becausethere are huge unmet needs in rural America forconstruction and improvement of water systemsand sewage systems.”

She emphasized that even though budget cutsare deep, USDA remains committed to providingtechnical assistance to small systems and steeringfunds toward Water 2000 communities—whichare those without safe drinking water.

“One of the things we have been very carefulabout is making sure that our technical assistanceeffort has remained close to the same as it was inFY95,” Long Thompson said, emphasizing thatthe technical assistance RUS can provide to thesmaller rural communities with water and wasteneeds becomes critical in times of limited funding.

“Even though the dollars are less for construc-tion and improvement costs, many times the tech-nical assistance combined with some innovativethinking about how we can combine funds andleverage federal dollars can help the dollars that wedo have go farther and reach more communities,”she said.

Long Thompson said that USDA is workingvery hard not only to become leaner and morecost effective, but they are also concentrating onimproving customer service. “While we are closinga number of our field offices, we are working toimprove our communications— redefining positionsamong our field employees so that we can engagein outreach,” she said. “We’re doing a good job ofoutreach even with a smaller field staff.”

Applications Are Processed QuicklyLong Thompson said Rural Development has

worked hard to assure that the grant and loanprocessing time remains steady and does not slow

“We still have about

a half a million

homes in rural

America that don’t

have any running

water. And then,

we have several

million other homes

that have water

supplies that do not

meet EPA

standards.”

Jill Long Thompson,Under Secretary

for the U.S.Department of

Agriculture’s RuralDevelopment

Continued on page 10

10 OnTap Summer 1996

What’s the word on water at the USDA?


that have the communities that do not have runningwater are targeting their water and wastewatermoney to those communities.”

She said Rural Development strives to addressboth water and wastewater system needs. “We’revery much aware that there are some cases whereproviding water infrastructure in a community canthen create a need for a wastewater infrastructure.

“If you have a community, a small town, forexample—where the homes are on wells andseptic systems—if a water system is installed,then that will create a need for a wastewatersystem or a sewer system.”

When that occurs, Long Thompson said,RUS attempts to help the community address thatproblem as well, and advises them of options theymight explore. Again, of course, so much dependson the availability of funds.

“Whether or not we’re able to meet the goalsof Water 2000 by the year 2000 will depend uponthe funding levels provided by the U.S. Congress.We are very seriously and intensely pushingahead, and we are doing everything we can tobe innovative, to partner with state governments,and to leverage the dollars and the resources thatwe have.”

Continued from page 9 USDA Unites Funds with Other AgenciesShe said the USDA is working on ways to

dovetail RUS funding with other federal agenciessuch as the EPA and U.S. Department of Housingand Urban Development (HUD).

“What we have worked to do in the Departmentof Agriculture in the RUS is to find ways thatwe can pair our money with money from othersources—whether it be private sector, or localor state tax dollars.

“That allows us to leverage the dollars that wehave to go farther by lending money rather thanmaking grants, or putting together a combinationloan and grant package that allows the money togo farther,” she said.

The Empowerment Zones and EnterpriseCommunities (EZ/EC) Initiative is designedto create self-sustaining, long-term economicdevelopment in areas of pervasive poverty,unemployment, and general distress. It is admin-istered through USDA’s Rural Developmentmission area that Long Thompson oversees.

She explained that this presidential initiativetargets communities that are most financiallystrapped. “We have both urban and rural commu-nities that are designated as empowerment zonesor enterprise communities, and we work withHUD and Health and Human Services [HHS]very directly on meeting those needs. In manycases there are water and waste needs that we’reworking on.”

Information on the EZ/EC home page statesthat 33 rural communities in 24 states have beenidentified for assistance, which includes HHSgrants, technical assistance, and tax-free facilitybonds. On the average, Empowerment Zone com-munities have a poverty rate exceeding 36 percentand an unemployment rate exceeding 14 percent.

She said the Farm Bill’s Fund for RuralAmerica authorizes $300 million—$100 millionfor each of FYs ’97, ’98, and ’99—to assist ruralcommunities. Each year the $100 million will bedivided among research and Rural Developmentand the USDA secretary will have the discretionof allocating the remaining third (i.e., $33.3 milliongoes to Rural Development; $33.3 million toresearch; and the remaining $33.3 million will bedivided between the two).

These funds are part of the historical $47 billionFarm Bill that passed in April, which, with a fewexceptions, lifts restrictions on what and howmuch farmers can plant. For decades the USDAhas subsidized farmers and placed restraints onwhat they can plant. This bill caps spending forthe first time, and guarantees farmers a series oftransition payments through 2002.Continued on next page

Jill Long Thompson, a long-time advocate for ruralAmerica, was raised on afarm in Indiana. She earneda bachelor’s degree from ValparaisoUniversity, a master’s degree in businessadministration and a doctoral degree inbusiness from Indiana University. LongThompson taught business and co-managed her family’s farm in Indiana.She won a seat on the Valparaiso, Indiana,City Council in 1983, and in 1989 waselected to represent Indiana’s FourthCongressional District.

Recognized on Capitol Hill as a championof rural issues, Long Thompson waselected Chair of the Congressional RuralCaucus in 1993 and since then has morethan doubled membership in the caucus.President Clinton appointed LongThompson to her present position with theU.S. Department of Agriculture in 1995.

OnTap Summer 1996 11

Continued from previous page greatest strength is the commitment that thepeople of local communities have to work toimprove quality of life, employment opportunities,etc. The real strength in rural development lieswith the local communities and the local govern-ments,” Long Thompson emphasized.

“We work as a partner. But the days when thefederal government believed it could go in andchange a community—those days are long behindus. The federal government doesn’t have theresources. We just don’t have the ability, and thatapproach probably never could work anyway.

“I don’t think there’s any question that as wemove toward the year 2000, that in addition toupgrading rural electric and rural telephonecommunications across the country, that we alsohave to have adequate water supplies and wastedisposal.” That’s one reason why Water 2000, shesaid, is intricately tied to the economic health ofrural America.

“I think the role of USDA will be to ensurethat whether you choose to live in rural Americaor urban America or suburban American, youhave access to good quality health care andgood quality education, and there are economicopportunities so that families and communitiescan prosper,” she said.

“A child who grows up in rural America oughtto be able to compete with children growing upall around the world. My vision for the USDARural Development mission area is that we workas a partner with state and local government andthe private sector to strengthen rural America.

“The biggest contribution of USDA is at leasttwo-fold: One is, of course, financial, and theother is technical assistance,” she said.

What can we do for rural development?“I think it’s important for everybody to make

their concerns known to their elected officials andthat includes not just federal officials, but stateand local. Before I was elected to serve in theU.S. House of Representatives and before cominghere, I always worked to make sure that the con-cerns I had were raised with my representatives,”she said.

“I firmly believe that while lobbyists play arole in the policy-making process, that electedofficials work very hard to be responsive to theirconstituents, to the people who elected them totheir position. There’s probably nothing moreeffective than writing a letter to your electedofficial expressing your opinion.”

“The funding in the Rural Development areawould be used for water and waste, as well as forhousing, so there’s no question that will help uswith the huge backlog of applications that wehave for money for water and sewer systems inrural communities,” Long Thompson said. “Idon’t think there’s any question that Water 2000will be enhanced as a result of the Fund for RuralAmerica.”

Is block granting a good idea?There is considerable discussion these days

about block granting. Long Thompson said thatwhile block granting works for certain kinds ofprograms, she doesn’t think it works well as areplacement for what they do in the Rural Devel-opment area in the USDA.

“It would constitute a real loss to rural commu-nities in the country,” she said. “In particular, thechallenge under block granting is the states wouldnot have the ability to leverage the dollars to theextent that we are able to in the federal government.The states that have the greatest need would behit the hardest because in order for a state to setup a revolving loan fund and offer a lower interestrate than in the market, they would have to have ahigh bond rating.”

Long Thompson explained that a high bondrating is based on having a portfolio of communi-ties, cities, and towns that are very strong finan-cially. “So there would always be the choice thatthe state would have to make: to keep the bondrating up, you only include the cities that pose theleast financial risk, and that means you’re notgoing to be able to lend money at lower rates tothe highest need communities.

“Because we have the U.S. Federal Treasurybacking whatever we do, we can offer lowerinterest rates, and we leverage the dollars muchfarther. In addition, we’re able to provide technicalassistance that the states would simply not be ableto provide. We run very cost-effective programs,and we not only administer them cost effectively,but we reach communities that are the hardestto reach—communities that simply cannot getfinancing from state or private sources.”

What challenges does rural America face?“I think the biggest challenge to small systems

is cost, and we find that the costs continue to goup. And that’s why we find that there is a need forpartnership between federal, state, and local gov-ernments and the private sector.

“Probably the greatest challenge for ruralareas in the next century is infrastructure. The


“Probably the

greatest challenge

for rural areas in the

next century is

infrastructure.”

Jill Long Thompson,Under Secretary for

the U.S.Department of

Agriculture’s RuralDevelopment


Town Treats Water with Chlorine DioxideContinued from page 1 monthly (warm weather) average only. The

wastewater and water billing rate is currently$1.83 and $1.62 per 100 cubic feet, respectively.

Littleton Decides To Upgrade“It’s generally a good water supply,” Betz

said, adding that the only disinfectant they usedin the past was sodium hypochlorite, which ischlorine in liquid form. It is slightly moreexpensive than chlorine gas, and though it iscorrosive, it is safer to handle than gas. Betz saidthe water system operator added bleach disinfectantat the intake, but since their reservoir was uncov-ered, it was necessary to disinfect again to assurewater quality.

The town decided that it needed a betterbackup water system and proposed a $3.5 millionbond issue to put in a new well. “We got a major-ity,” Betz said, “but in New Hampshire you needa two-thirds vote.” So they went back to thedrawing board.

“We took another look and found that inEurope chlorine dioxide is fairly common. Itgave a good CT.” Usually expressed in units ofmilligrams per liter (mg/l) by minutes, CT refersto the concentration of disinfectant multiplied bythe time it takes to kill disease-causing organisms(CT = concentration x contact time). In otherwords, a given percentage destruction of a certainorganism can be obtained by balancing doseagainst contact time.

“And we would be able to maintain a gravity-fed water supply,” Betz added.

Aside from environmental and health consid-erations, the initial cost of installing a chlorinedioxide system would be far less than drilling anew well to a groundwater source. Of course,chemical costs and the cost of running each systemhad to be taken into account.

“We had notices and public hearings,” Betz said.“People liked the idea of not raising water rates.”After considering public comments, three commis-sioners for Littleton Water and Light made thedecision to procure a chlorine dioxide system.

What is chlorine dioxide?Chlorine dioxide (ClO

2) is a powerful disin-

fectant and oxidizing agent applied in treatmentplants for controlling tastes and odors, disinfection,oxidation of iron and manganese, and controllingtrihalomethanes (THMs) formation. THMs, disin-fection by-products, are formed by the reaction ofnatural organic matter, such as humic and fulvicacids, or animal waste, and chlorine. Chlorinedioxide does not react with ammonia to formless-active chloramines and will not form THMs.

at the Samuel C. Moore Dam on the ConnecticutRiver in Littleton. NEPCO established the190,000-kilowatt hydroelectric complex in the1950s and it has been a boon for the town’s taxbase, as well as an asset for recreation.

Ed Betz, P.E., an engineer and superintendentfor Littleton Water and Light Department, explainedthat Littleton’s drinking water comes from thewatershed approximately 12 miles away. Waterflows by gravity without pumping at a rate of upto 1.8 million gallons per day (gpd). As a backup,the town has a drilled rock well capable of sup-plying another 400,000 gpd.

Meters Help Conserve WaterLittleton’s water system has been metered

since 1989. “The use of water meters has had asignificant positive impact on water conservation.It allows us to maintain our existing gravity surfacewater supply in lieu of developing more expensivegroundwater alternatives,” Betz said. He explainedthat prior to 1989 Littleton regularly experiencedwater shortages in the winter months when

customers ran their water continually to keeppipes from freezing, and in summer months whencitizens over-watered lawns and gardens.

Littleton has an available safe yield watersupply of 2.2 million gpd and averages dailymetered flows of 470,000 gpd for 1,600 industrialand residential water users. The average dailyresidential consumption is approximately 150 gpd.

“We have seen a steady decline in water con-sumption since 1989, especially when sewer billswere tied into metered water consumption in1994,” Betz said. “To date, about 50 percent ofshallow/galvanized water services have beenlowered or insulated to prevent freezing.”

He explained that where water services muststill be run in the winter months to prevent freez-ing, a credit of 2,000 cubic feet per month isallowed for running water. Customers who usefewer than 2,000 cubic feet are billed their

Solar panels aremounted on the roofof Littleton’sdisinfection andtreatment facility atNorth Branch of GaleRiver in White MountainNational Forest.


Continued on next page


Continued from previous page “We needed to increase the disinfectioncontact time provided to our first customer by afactor of better than 30 [times greater than it hadbeen]. Therefore, we moved our disinfectionpoint 8,000 feet up the transmission main behinda one million-gallon sedimentation basin adjacentto our Gale River intake, and changed the disinfec-tion process to chlorine dioxide. Taste and odorwere really secondary.

“If raw water is high in organics, it can causeproblems with taste or odor,” he said, “but wedon’t have that problem.” Algae, some microor-ganisms, and such inorganic compounds as ferrous(derived from iron) and manganese ions, can alsocause taste and odor problems.

“Another benefit,” he added, “is that we needless chemicals, as chlorine dioxide is a morepowerful disinfectant. We’re not dependent on thepH of the water and we’re less dependent on thetemperature of the water with chlorine dioxide.”Littleton did not have pH problems.

It’s Not for EveryoneBetz said that there are major factors to consider

when deciding whether or not to install a chlorinedioxide system. “It is quite a bit more sophisticatedthan other chlorination systems.”

However, their principal concerns are relatedto safety: primarily, employees handling volatilesubstances. “Sodium chlorite can be flammable,”he said, noting that if the substance is spilled,when it dries, it can ignite very, very easily.

An additional expense with this type of systemis alarms. “There are alarm systems to monitorgas,” Betz said, adding, “Littleton has a radiotelemetry system for monitoring water. We don’tneed an onsite operator.” They do have a telephoneenunciator system, and if alarms go off or any-thing in the system needs to be attended to,someone on call is alerted via phone.

According to a June 1992 Journal AWWAarticle, “Tastes and Odors Associated with ChlorineDioxide,” although most of the ClO

2 is consumed

during treatment, its by-products—chlorite(ClO

2–) and chlorate (ClO

3–) ions— appear in the

distribution system. In the future, utilities may berequired to meet additional EPA standards forresidual oxidants.

A regulatory standard of <1.0 mg/l for totaloxychloride residuals in drinking water is beingconsidered. This standard is based on possibleadverse health effects associated with the consump-tion of ClO

2, ClO

2–, and ClO

3–. According to the

article, oxychlorine compounds are known tocause oxidative stress, hemolytic anemia, andinflammation of nasal passages in mammals.

(See Q&A, page 16, for a discussion of disinfec-tion by-products.)

The U.S. Environmental Protection Agency(EPA) recognizes chlorine dioxide as a primarydisinfectant, but because it is volatile and danger-ous to transport, it must be generated onsite.Aqueous sodium chlorite (NaClO

2) solution and

chlorine gas (Cl2) are mixed onsite, causing a

chemical reaction that produces a solution ofchlorine dioxide.

2NaClO2+Cl

2 —> 2ClO

2+2NaCl

Chlorine dioxide is generally more expensive,but also more powerful, than disinfectants such assodium hypochlorite alone. It is often selectedbecause the CT is less, it does not impart a chlorinetaste to water, and there are fewer concerns aboutdisinfection by-products.

Is the cost of chlorine dioxide prohibitive?The word in the water business is that chlorine

dioxide is too expensive to make it a viable treat-ment option.

“We had heard that too,” Betz said. He’dheard that the cost would be approximately 1.5times the cost of sodium hypochlorite, but thetown hasn’t found that to be true. “We treat 1,200gallons a minute using eight to 10 gallons a dayof concentrated chlorine dioxide. It costs $14,000per year for chemicals—chlorine gas and sodiumchlorite. That’s about the same as we were payingfor sodium hypochlorite.”

Of course, he admitted, “We may have beendouble disinfecting before. We had an open servicereservoir and we disinfected before and after thereservoir.” Among Littleton’s recent improvementsis a new covered reservoir. Open reservoirs aremore subject to seasonal variation than coveredones. And temperature can affect certain steps inthe disinfection process, such as reaction rate.

Chlorine dioxide does require a lot of peripheralequipment, Betz said. The town spent $27,000 onthe chlorine dioxide system, “as opposed to about$500 for a pump to pump bleach.”

Since the town’s finances are in good shape,there was no need to obtain loans for the systemupgrade. “After we installed the system, wereceived a retroactive 20 percent grant from thestate,” Betz said. “That was a bonus.”

Chlorine Dioxide Has Advantages“We had advantages—chlorine dioxide

doesn’t react with organic particles to form carci-nogenic disinfection by-products,” Betz said, butexplained that the primary reason Littleton chosechlorine dioxide is contact time.

Continued on page 14



Town Treats Water with Chlorine DioxideContinued from page 13 Littleton’s system is solar powered with a

liquid propane (LP) backup generator. The plantequipment and pumps are powered by 720-watt,30-ampere photovoltaic modules. Betz saidthat on long cloudy days they use the bottledpropane backup.

“Because our disinfection facility is about8,000 feet away from electric utility service, wehad to construct an onsite power supply,” Betzexplained. “Solar panels with storage batteriesare our principal power supply, with an LP gaselectric generator and inverters which act asbattery chargers and convert AC to DC power.”

At a flow rate of 750 gallons per minute anda dosage of 0.2 mg/l, the chlorine dioxide require-ment is 2.2 pounds per day. It has a maximumcapacity of 80 pounds per day.

This system makes up chlorine dioxide on acontinuous batch process. Betz said that chlorinegas, sodium chlorite liquid, and water are combinedunder 90 pounds of pressure to produce a 2 percentsolution of chlorine dioxide in 40-gallon batches.

“It automatically batches again when the 40-gallon reservoir drops,” he explained. Levelprobes in the chlorine dioxide holding tank monitorthe stored solution level and start and stop thebatch cycles. Chemical feed rates are fixed.

The W&T system uses manually set feed ratesof sodium chlorite and a high concentration chlo-rine solution to completely convert the sodiumchlorite to chlorine dioxide. Since the resultingchlorine dioxide solution is unstable, it is dilutedto a more stable concentration. The systemconverts 96 to 98 percent of sodium chlorite tochlorine dioxide. W&T guarantees 96 percent orgreater efficiency with their system.

No maximum contaminant levels exist foroxychloride residuals; however, some statesrequire monitoring.

“We’ve had tests for chlorites,” Betz said.“They’ve tested well below the new disinfectantresiduals guidelines.” Chlorites in Littleton’ssystem tested at .4 mg/l. “And most THMs noware below detection. Before we were up around40 to 80 mg/l.

“The University of New Hampshire is doing astudy on disinfection by-products,” he added.“They’re doing tests. We’re doing tests.”

Betz said another concern was that he’d readchlorine dioxide can react with the formaldehydein new carpets to cause odors like kerosene or caturine. (See Journal AWWA article mentionedabove.) “But we have not experienced that.”

Littleton Selects a Solar SystemBetz said that while a number of companies

offer chlorine dioxide systems, the Wallace &Tiernan (W&T) Series 85-250 Chlorine DioxideSystem best fit their needs.

The main components of the system are achlorinator, vacuum switch, sodium chloritepump and supply tank (user furnished), reactiontower, control panel, water-pressure regulator,solenoid valve, flow meters, and a holding tank.Piping, hardware, and sensors and controls thatmonitor system operation are also included.

Solar Panels

Power Control Paneland Inverter

Bank of StorageBatteries (24v)

Flow Meter

Chlorine DioxideGenerator

Chlorinator

Cylinder

Sodium ChloriteSolution

ChemicalPump

ReactionTower

HoldingTank

DosingPump

Standby/EmergencyHypochlorinatorSystem

SourceSupply Main

Distribution

Makeup Water


Basic Solar-Powered ChlorineDioxide System




Water Fact

Seventy-fivepercent of thehuman brain

is water.

—EPA DrinkingWater Activities

for Teachersand Students

Continued from previous page goes on automatically. “That’s less than 3 percentof the year,” Betz said, adding, “we do havestrong bleach odor complaints if we go back toour standby hypochlorite system even temporarily,as the free chlorine from hypochlorite appears toreact with chlorine dioxide residuals. But normallywe have no problems. We get compliments on ourwater quality.”

The U.S. Department of Energy recognizedLittleton Water and Light Department with acertificate for installing the first chlorine dioxidedisinfection treatment system in New Hampshire.

“I’m not sure we know everything there is toknow about chlorine dioxide,” Betz said. “We’relearning all the time.”

Littleton Plans System ImprovementsLittleton is planning further system improve-

ments this year by constructing an infiltrationgallery intake structure on the Gale River thatshould reduce operational costs and reduce rawwater turbidity.

“Presently, we have bar racks and coarsescreens which plug up with leaves, debris, andfrazil ice [ice that adheres to metal and the riverbottom] in the winter months,” Betz said. “Theinfiltration gallery will consist of a parallel seriesof 12-inch diameter perforated pipes placed fivefeet below the river bed, backfilled with washedsand, coarse stone, and gabion baskets. Theperforated pipes will be intercepted by a largeconcrete well tile.

“We are also conducting a slow sand pilotfilter to determine the feasibility of convertingan existing concrete sedimentation basin, 90 feetby 120 feet by 12 feet deep, into a slow sand filterto improve efficiency removal of turbidity andorganics.”

He explained that the point of disinfectionwould then be moved below the sedimentationbasin. “By retrofitting the existing basin wewould expect to save substantial constructioncosts over new facilities.”

For more information about Littleton’s watertreatment system, contact Betz at (603) 444-2915,Littleton Water and Light Department, 30Lafayette Ave., Littleton, NH 03561, or BillHealey, instrumentation engineer, 180 HealeyTerrace, Brockton, MA 02401. See the Tech Briefinsert in the center of On Tap for a comparison ofdisinfectants. See page 16 for information ondisinfection by-products.

The chlorination equipment with the systemincludes a switch-over type of vacuum regulatorso the system operation will continue when oneof the chlorine cylinders is empty. Alarms willshut down the system if there is a malfunction.

There is a fume-evacuation injector in the ventline from the holding tank to control off-gassingduring generation.

Town Obtains a Filtration WaiverWhen the bond issue for a groundwater supply

failed to pass in July 1992, Littleton pursued awaiver of filtration option based on generallyexcellent raw water quality. But a waiver is notsimple to obtain or to maintain. The town receiveda waiver only after it adopted watershed protectionregulations; constructed the new chlorine dioxidedisinfection facility; installed corrosion controlusing sodium hydroxide and polyorthophosphate;purchased radio telemetry data acquisition andmonitoring equipment; installed a new coveredwater storage tank; and finished transmissionmain improvements.

“With a waiver for avoidance, we are nowrequired to monitor the raw water quality threetimes a week by taking fecal counts,” Betz said.And they have to continually record turbidity.“We also have to maintain a sufficient chlorinedioxide disinfection contact time which varieswith flow and water temperature. We have tomaintain a minimum disinfection residual at theentry point and throughout the distribution system,and vigorously monitor and control watershedactivities with the assistance of the U.S. ForestService.”

Betz said that the waiver for avoidance optionincreased annual operating costs by approximately$11,700, including increased water quality testingcosts ($5,200); increased labor, principally over-time ($3,500); and LP gas heat/fuel ($3,000).The town still maintains its gravity water supply,thus avoiding approximately $81,000 in increasedpumping costs from a groundwater option. Andanother $130,000 per year is saved on bondrepayment.

Chlorine Dioxide Experience Is PositiveBetz said that he’s not a salesman for chlorine

dioxide, but Littleton has experienced very fewproblems in the two-and-a-half years since itinstalled its system. They have had electrical prob-lems from lightning strikes and backup generatorproblems. There have been no safety violations.

When the electric supply goes down to lessthan 20 amperes, the backup hypochlorite system


QUESTION & ANSWERQUESTION & ANSWER

Disinfection of water is needed to destroy anygerms during the treatment process, and to remainin the water to ensure the water quality.

Disinfection is usually the last stage in watertreatment because effective disinfection can bedone only when water is relatively pure. Presenceof organic material, suspended solids, and othercontaminants (also referred to as precursors) canaffect the quality of disinfection. If the concentrationof organic matter is high, the organic compoundswill use up the residual disinfectant, thus affectingsecondary disinfection.

Disinfection also leads to production of disin-fection by-products (DBPs) that may be detrimentalto human health. Some of the DBPs have beenproven to be carcinogens (especially vulnerableare the bladder, colon, and rectum) and mutagensin certain laboratory animals. However, the con-nection to humans has not yet been substantiallyproven. Further research into the effects of DBPson human health is needed to accurately assessthe risks associated with them. When naturalorganic matter (NOM) in the water reacts with thedisinfectant, organic DBPs are formed, and wheninorganic matter reacts with the disinfectant,inorganic DBPs are formed.

DBPs can be divided into subgroups:trihalomethanes (THMs), haloacetic acids,haloactonitriles, haloketones, halopicrins,halophenols, chloral hydrates, chlorates, chlorides,and bromates. The types and amounts of DBPsproduced depend upon the dosage and type ofdisinfectant used, the level and nature of naturalprecursors, pH, contact time with the disinfectant,temperature, season, and the water source. Afine balance has to be struck to minimize theproduction of DBPs and maximize the qualityof disinfection itself.

The existing regulation by the U.S. Environ-mental Protection Agency (EPA) requires utilitiesserving more than 10,000 people to comply witha maximum contaminant level (MCL) of 0.10milligrams per liter (mg/l)—100 micrograms perliter (µg/l)—for Total Trihalomethanes (TTHMs).

Under the proposed Disinfectant and Disinfec-tion By-Products (D/DBPs) Rule, the EPA intendsto establish maximum residual disinfectant levels(MRDLs) for chlorine, chloramines, and chlorinedioxide and MCLs and maximum contaminantlevel goals (MCLGs) for some selected by-productsthat are known to be a threat to human health.Since the proposed regulations apply to allcommunity water systems and nontransient non-community water systems that add a disinfectantduring any part of the treatment process, thesenew regulatory changes will impact most waterutilities in a major way. Certain provisions in the

proposed rules also apply to transient noncommu-nity water systems using chlorine dioxide.

A community water system is one that has 15or more service connections or regularly servesan average of at least 25 people year round.

An nontransient noncommunity system is onethat serves the same 25 people for at least sixmonths a year but not year round.

The table on this page provides the proposedlevels under the D/DBP Rule for both stages ofthe rule:

µg/l = micrograms per litermg/l = milligrams per literMCL = maximum contaminant levelMRDL = maximum residual disinfectant level

* Stage II levels are to be further researched and willbe finalized when all the results of the InformationCollection Rule are available.

The following is a brief description of thevarious strategies that can be employed forDBPs control:

(a) Source Control: Some research has suggestedthat this approach requires further researchbefore it can be applied to practical situations.Many researchers believe that controllingthe nutrient content in the raw water source,thus limiting the algal growth potential ofthese waters reduces the amount of NOM,which in turn would aid in reducing DBPs.Another alternative would be to draw waterduring the months when the water qualityis conducive to reduced levels of DBPsproduction and store it for use during highDBPs production seasons.

(b) Precursor Control: The major technologiesavailable presently for precursor control areenhanced coagulation, granular activatedcarbon adsorption, and membrane filtration.The choice of alternative depends upon theexisting technology at the utility in consider-ation and the associated costs.

What are disinfection by-products?

Compound MCL/MRDL

Stage I Stage II*

Total Trihalomethanes 80 µg/l 40 µg/l

Haloacetic Acids (five) 60 µg/l 30 µg/l

Bromate 10 µg/l

Chlorite 1.0 mg/l

Chlorine 4.0 mg/l

Chloramines 4.0 mg/l

Chlorine Dioxide 0.8 mg/l



The Water Librarian’s Home Page at http://www.wco.com/~rteeter/waterlib.html providesnumerous links to sites of interest to On Tapreaders. The page is maintained by a librarian inCalifornia, and provides connections to a widevariety of Internet materials related to waterresearch and the environment.

The sites are broken into the following catego-ries: water agencies (mostly civil institutions), waterreference databases, comprehensive water pages(many general interest materials included), andother sections related to water resources, such asearth science, government agencies, and environ-mental science materials.

The water agencies category includes a sectionwith a list of water utility home pages from around

Water Librarian’s Home Page Is Onlinethe world. The water reference databases categoryincludes links to an encyclopedia of water termsfrom the Texas Environmental Center and a linkto the National Water Quality Database fromPurdue University.

The comprehensive water pages section includeslinks to sites, such as the American Water WorksAssociation.

This information was extracted from a U.S.Environmental Protection Agency HeadquartersLibrary Internet News Brief.

To subscribe to Internet Newsbrief, send a mes-sage to [email protected] with thefollowing in the body of the message: subscribeINTERNETNB-L first name last name.

National Rural Water Association Is on the WebThe National Rural Water Association

(NRWA), a federation of independently governedstate Rural Water Associations that provide train-ing and technical assistance, is online at http://www.cais.net/nrwainfo/.

Rural Water’s mission is to improve the qualityof utility services for rural America while protectingnatural resources. This Web site offers information,such as, an informal question and answer section,links to other water-related sites on the Web, and

the text of the sections of the Farm Bill Confer-ence Report related to the U.S. Department ofAgriculture’s (USDA) Rural Water and SewerProgram and Fund for Rural America. (See theJill Long Thompson interview on page 1 formore information on USDA programs and theFund for Rural America.)

Future plans for the NRWA home page includea list of water system problems and creativeremedies.

What are disinfection by-products?

(c) Alternative Disinfectants: A number ofoptions are available for consideration and,as mentioned before, a tradeoff betweenthe quality of disinfection and the DBPsformation will have to be made. Advancedoxidation processes—the chemical reactionbehind the concept of disinfection—involvinga combination of two or more of the availabletechnologies are also being researched.However, similar problems, especially thatof coping with secondary disinfection, exist.

The proposed D/DBPs rules are just a beginningin trying to regulate the contaminants produced asa result of disinfection.

The issues of technology, costs, benefits, andhealth effects of all the by-products will have tobe researched thoroughly before any kind offinality can be achieved for controlling DBPs.

ReferencesBull, R.J., et al. 1990. Evaluation of the Health Risks

Associated with Disinfection, Critical Reviews inEnvironmental Control, 20, no. 2: 77–113.

R E S O U R C E SR E S O U R C E S

Continued from previous page Degrémont. 1991. Water Treatment Handbook, vols. 1and 2, Sixth Edition, Secaucus, NJ: LavoisierPublishing, Inc.

Glaze, W.H., et al. 1993. Determining Health RisksAssociated with Disinfectants And DisinfectionBy-Products: Research Needs, American WaterWorks Association Journal, 85, (March): 53–6.

Rest, G.B. 1996. Disinfection By-Products: TheTechniques of Control, Public Works, 127, (January):36–8.

Singer, P.C. 1994. Control of Disinfection By-Productsin Drinking Water, Journal of EnvironmentalEngineering, 120, no. 4 (July/August): 727–44.

U.S. Environmental Protection Agency. 1994. FederalRegister, vol. 59, no. 145, Proposed Rules. EPA811Z94004.

U.S. Environmental Protection Agency. 1989. PublicWater Systems: Providing Our Nation’s DrinkingWater. Office of Water. Washington, DC: EPA 570/9–89–DDD.



Drinking Water Education Is Easy and FunAre you looking for an easy and fun way to

teach students about the importance of drinkingwater protection? If so, you may want to order akit compiled by the U.S. Environmental ProtectionAgency (EPA), “Drinking Water Activities forTeachers and Students.”

Developed for elementary and middle schoolstudents and their teachers, this kit includes factsabout drinking water, groundwater, and waterconservation. It also includes games, projects, andsuggestions for other activities that are fun, butcarry the message that drinking water needs tobe cared for.

Some games the kit includes teach studentshow groundwater moves through the ground and

how it recharges and discharges from an aquifer.Additional activities show students how aquiferscan become contaminated, while others teachstudents how drinking water can be cleaned.

The kit also contains Blue Thumb activities—developed by the National Drinking WaterWeek Alliance—such as drinking water trivia,in-classroom experiments, and water conservationfact sheets.

To order this free kit, call the National Drink-ing Water Clearinghouse at (800) 624-8301 andask for item #DWPKPE39. Shipping and handlingcharges will apply.

NDWC, NSFC, NETCSC Offer Free Catalogs

NAT

IONAL SMALLFLO

WSCL

E

AR INGHOUSE

1996Guide toProducts

1996Guide toProducts&ServicesServices

National Small FlowsClearinghouse1-800-624-8301

National EnvironmentalTraining Center

for Small Communities

1-800-624-8301

1996Environmental

TrainingResources

Catalog

1996Environmental

TrainingResources

Catalogfor Small Communities

NA

TIO

NA

L ENVIRONMENTAL

TRAINING CENTER

National Drinking WaterClearinghouse

1-800-624-8301

1995-96Guide to

Products1995-96Guide to

Products&ServicesServices

have in the past,” says Vernon Deal, supervisorof the Environmental Services and TrainingDivision’s (ESTD) resource center.

The ESTD is comprised of the NDWC and itssister organizations—the National Small FlowsClearinghouse (NSFC) and the National Environ-mental Training Center for Small Communities(NETCSC)—which also offer similar guidesrelated to wastewater and small communityenvironmental training, respectively.

To order any of these catalogs, call(800) 624-8301. For a free copy of the NDWC’s1995–96 Guide to Products and Services, requestitem #DWCAT. For copies of the NETCSC catalogor the NSFC catalog, request item #NETCAT3 orSmall Flows CATALOG.

The National Drinking Water Clearinghouse(NDWC) is now offering its new products catalog,which contains information about 150 free orlow-cost drinking water products. Customers willfind a new pricing structure for NDWC’s productsin this catalog.

“The new pricing structurestandardizes prices

across theboard and

provides fairmarket prices to

our customers sowe can function

more efficientlyand continue to

provide the high levelof service that we

Small System Pocket Guide Explains SDWAOwners and operators of small drinking water

systems will want to order a free copy of the“Safe Drinking Water Act: A pocket guide to therequirements for the operators of smallwater systems.”

This convenient, easy-to-understandsummary provides a useful overview ofdrinking water standards; reporting,record keeping, and public notificationrequirements; and sampling frequencies,location points, and procedures. Appendicesinclude details about the sources and health effectsof drinking water contaminants, as well as the rulesgoverning lead and copper, surface water treatment,and the standardized monitoring framework.

Developed by the U.S. Environmental Protec-tion Agency’s Region 9 office, the 82-page book-let is indeed small enough to fit in a pocket.

For a copy of the Safe Drinking Water Actpocket guide, call the National Drinking WaterClearinghouse (NDWC) at (800) 624-8301,and request item #DWBLRG25. A postagecharge will apply. To learn more aboutthe NDWC’s other services, also request afree information packet, which includes a

complete products catalog (see related articlebelow) and explains the technical assistance andreferral line and the Drinking Water InformationExchange Bulletin Board System.

June 1993

The Safe Drinking Water Act

A pocket guide to the requirements

for the operators of small water systems



Water and Wastewater Information AvailableThe Environmental Services and Training

Division (ESTD) at West Virginia Universityoffers publications that provide information ondrinking water, wastewater, and environmentaltraining.

The ESTD is comprised of the NationalDrinking Water Clearinghouse (NDWC) and hersister organizations—the National Small FlowsClearinghouse (NSFC) and the National Environ-mental Training Center for Small Communities(NETCSC).

Water Sense Offers Financial InformationThe NDWC’s newest publication—Water

Sense—helps small communities learn aboutdifferent ways to finance their drinking water andwastewater projects and effectively manage theirsystems. Water Sense articles complement thetechnical and regulatory information provided inOn Tap.

The latest issue of Water Sense (Spring 1996)includes articles on forming a water authority, set-ting up a retention schedule for system documents,and tapping into funds from the U.S. Departmentof Housing and Urban Development’s CommunityDevelopment Block Grant program.

The newsletter also offers legislative updates,and points readers toward assistance providers,publications, and other resources to help meetsmall systems’ financial needs.

E-Train Boasts New Look in Spring IssueE-train, an environmental training newsletter

for small communities, is published quarterly byNETCSC.

The Spring 1996 E-train reflects a new designin an 8-1/2 by 11-inch format. The newsletter wasreformatted in response to a readership survey.Readers favored the smaller size by a two-to-onemargin, citing ease of copying, faxing, and filingas the primary reasons. NETCSC Graphic DesignerDaniel Gloyd redesigned the newsletter to giveE-train a distinct visual image.

The newsletter supports environmental trainersin their efforts to improve the quality of waste-water, drinking water, and solid waste servicesin small communities.

Each issue includes profiles of successfultraining programs, hands-on training tips andtechniques, feature articles, news relevant to theenvironmental training field, as well as reviewsof training resources. Submission of news itemsis welcome.

For free subscriptions to Water Sense orE-train, call (800) 624-8301. You can also writeto NDWC or NETCSC at West Virginia University,P.O. Box 6064, Morgantown, WV 26506-6064.

News from the National Small Flows Clearinghouse

Small Flows is intended for a wide variety of readersincluding engineers, regulators, and other technicalprofessionals. Community officials, students, andprivate citizens also will find the publication informative.

The Small Flows Journal Publishes Research The NSFC recently published the second issue of

The Small Flows Journal —a peer-reviewed technicaljournal devoted specifically to small community waste-water issues.

Articles in this issue include reports of a study byengineers at the University of California-Davis on therelationship of media depth and the performance ofshallow intermittent sand filters, and a proposal for anew private-market approach to managing onsitewastewater treatment systems.

For free subscriptions to Pipeline, Small Flows, orThe Small Flows Journal, call (800) 624-8301. You canalso write to NSFC at West Virginia University, P.O. Box6064, Morgantown, WV 26506-6064.

Pipeline Explains Wastewater to the Public Local officials, engineers, contractors, and others who

present and explain wastewater issues to the public willappreciate the newsletter Pipeline. Published by theNational Small Flows Clearinghouse (NSFC), Pipeline iswritten for the general public, and each issue focuses ona specific wastewater technology or theme of interest tosmall communities.

Recent issues of Pipeline have focused on combinedsewer overflows, septic systems, septic system mainte-nance, aerobic systems, and management programs foronsite and small community wastewater treatment.Newsletters can be ordered in bulk for a minimal charge,reproduced in newspapers, or distributed to residents.

Small Flows Focuses on Wastewater Issues Small Flows, a quarterly NSFC newsletter, is devoted

primarily to wastewater information for small communi-ties, but also features articles that highlight issuesshared by those interested in drinking water, includinggroundwater, public education, water conservation,watershed management, and plumbing standards.


C O N T E N T SC O N T E N T S

NA

TIO

NAL DRINKING WA

TE

R

C

LEAR IN GHOUSE

National Drinking Water ClearinghouseWest Virginia UniversityP.O. Box 6064Morgantown, WV 26506-6064

On Tap is printed onrecycled paper.

NonprofitOrganization

U.S. Postage PaidPermit No. 34

Morgantown, WV

NDWC Offers Resources for Small SystemsNote: The free items listed below are limited toone of each per order. Call (800) 624-8301 toorder products. Please allow four to six weeks fordelivery. Actual shipping charges are added toeach order.

RESULTS Database Version 2.0Item #DWSWGN25The National Drinking Water Clearinghouse’s

drinking water treatment technologies database,Registry of Equipment Suppliers of TreatmentTechnologies for Small Systems, or “RESULTS,”contains information about nearly 175 smalldrinking water systems and manufacturers. (Seearticle on page 4.) Data is continually beingsought and received. Both DOS and Macintoshversions of RESULTS 2.0 are available andrequire approximately 1.5 megabytes of memoryand 3 megabytes of hard drive space.

Cost: $5

Andrew W. Breidenbach EnvironmentalResearch Center Small SystemsResource DirectoryItem #FDPCGN11Published by the U.S. Environmental Protection

Agency’s Office of Research and Development,this 1992 document describes the center’s 29drinking water-related research projects, as wellas other environmental studies. Each projectlisting includes introductory information, adescription of the project, a list of related availablepublications, and a research center contact.

Cost: $0.00

Tech Brief: DisinfectionItem #DWBRPE47Extra copies of this fact sheet are available.

(See center pages for product.)Cost: $0.00

EPA’s Office of Ground Water andDrinking Water PublicationsItem #DWBKGN23This 1994 publication lists more than 400

available drinking water publications distributedfree by the U.S. Environmental ProtectionAgency’s Office of Ground Water and DrinkingWater. Included are such items as fact sheets,technical assistance documents, youth educationmaterials, scientific fact finding reports, andFederal Register notices.

Cost: $0.00

Water Cycle: Nature’s Recycling SystemItem #DWBLPE35This 1993 poster illustrates the hydrologic

cycle and provides definitions of the water cycle.Water facts and conservation information areprovided on the back of the poster. Activitiesfor school children are also included.

Cost: $0.00

The Benefits of Water and WastewaterInfrastructureItem #DWPCRE05This report addresses the need for the U.S.

government to continue to support water andwastewater infrastructure funding. The 14-pagedocument discusses clean water’s benefits tohealth, economic development, environmentalprotection, standard of living, and technologydevelopment.

Cost: $0.00

Features:

What’s the word on

water at the USDA?

page 1

Town Treats Water with

Chlorine Dioxide,

page 1

On Tap Survey

Results Are Announced,

page 3

Search for Clean

Water Continues,

page 6

NDWC Tech Brief,

center pages

Departments:

NDWC Page,

page 2

News and Notes,

page 3

Q&A,

page 16

Resources,

page 17

NDWC Mission StatementThe National Drinking Water Clearinghouse

assists small communities by collecting,developing, and providing timely information

relevant to drinking water issues.

ADDRESS CORRECTION REQUESTED

Date post:	19-Apr-2020
Category:	Documents
Upload:	others
View:	1 times
Download:	0 times

OnTap · OnTap Summer 1996 1 OnTap Drinking Water News For America’s Small Communities Summer...

Documents