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United StatesEnvironmental ProtectionAgency

Office of Research andDevelopmentWashington, DC 20460

Drinking WaterTreatment for SmallCommunities

A Focus on EPA’sResearch

EPA/640/K-94/003May 1994

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EPA’s Office of Research and Development

The Office of Research and Development (ORD)conducts an integrated program of scientific research anddevelopment on the sources, transport and fate processes,monitoring, control, and assessment of risk and effects ofenvironmental pollutants. These activities are implementedthrough its headquarters offices, technical support offices,and twelve research laboratories distributed across thecountry. The research focuses on key scientific andtechnical issues to generate knowledge supporting sounddecisions today, and to anticipate the complex challengesof tomorrow. With a strong, forward-looking researchprogram, less expensive more effective solutions can bepursued and irreversible damage to the environment can beprevented.

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Drinking Water Treatment for Small Communities

A Focus on EPA’s Research

The U.S. Environmental Protection Agency (EPA) projectsthat new drinking water standards will help prevent hundredsof thousands of cases of disease each year and will provideincreased health protection for all Americans served by publicwater systems. The new standards include requirements forincreased water utility monitoring of water quality to ensure itssafety. Where contaminants are present at levels exceedingthe standards, utilities will need to provide treatment. Manyutilities will need to upgrade existing treatment facilities ordesign new ones, and tens of thousands of small systems(3,300 or less population served) may find it difficult to meet thenew requirements.

To address these needs, EPA’s Office of Research andDevelopment (ORD) is working with industry, states, andcommunities to adapt alternative treatment technologies tosmaller scale to ensure that regulatory requirements can bemet cost-effectively and realistically by even the smallestjurisdiction.

This effort focuses on treatment technologies for smallsystems, including prefabricated central treatment systems(package plants) and home treatment units, to reduce biologi-cal, chemical, and radiological contaminants to acceptablelevels in water supplies. Small communities throughout thenation with differing raw water qualities are participating inORD’s studies to test and evaluate treatment technologies.Results to date indicate that small systems can upgradedrinking water quality at a reasonable cost.

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Water Use

Americans use about 12billion gallons per day in publicwater supplies. This demand is filledby the nation’s abundant fresh waterresources in over 2 million miles ofstreams, 30 million acres of lakesand reservoirs, and huge under-ground aquifers (subsurface geologicformations that store water). About50 percent of the population receivesdrinking water from surface watersupplies and 50 percent from groundwater sources. Most large cities usesurface water as their drinking watersource, but small towns or commu-nities with populations of less than3,300 most often use ground water.Currently, about 50 percent ofground water supplies are disin-fected. However, with new regula-tions, disinfection of all groundwaters will be required to inactivateorganisms or microbial contami-nants, called pathogens, that producedisease. About 13 million people (5percent of the population) drawwater from private wells, which arenot federally regulated under theSafe Drinking Water Act .

Community watersystems.

Number of Systems = 59,266

Medium, Large, &Very Large

Population Served = 232,562,000

Very Small &Small

Very Small &Small87%

Medium, Large, &Very Large

System Size and Population Served: Very small (25-500): Small (501-3,300); Medium(3,301-10,000); Large (10,001-100,000); Very Large (More than 100,000)

13% 11% 89%

The majority of our nation’swater suppliers are small systemsserving 25 to 3,300 people. Eighty-seven percent of community watersystems serve only 11 percent of thecommunity system population, andtwo thirds of all systems servecommunities of fewer than 500people. Small and very smallcommunity water systems servefewer than 26 million of approxi-mately 233 million customers in thecountry.

Many small systems will findit difficult to comply with newenvironmental regulations becausethey cannot afford the necessaryequipment or staff for treatment. Asadditional contaminants areidentified in drinking water andstandards are developed, thecomplexity of managing watersystems, especially for smallsystems, will increase greatly.

Sources of Contamination

Treating water supplies toremove health-threatening contami-nants is costly. Some pollutants are

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Contaminants Health Effects Sources

Microbiological Acute gastrointestinal Human and animal fecalillness, dysentery, hepatitis, mattertyphoid fever, cholera,giardiasis, cryptosporidiosis, etc.

Arsenic Dermal and nervous system Geologicaltoxicity

Lead Central and pheripheral Leaches from lead pipesnervous system damage; kidney and lead-based solder,effects; highly toxic to infants pipe jointsand pregnant women

Nitrate Methemoglobinemia (“blue Fertilizer, sewage, feedbaby syndrome”) lots

Fluoride Skeletal damage, dental Geologicalfluorosis

Pesticides and Nervous system toxicity, Farming, horticulturalherbicides cancer risk practices

Trihalomethanes Cancer risk Treatment by-product

Radionuclides Cancer Geological

harmful in small amounts, and canbe difficult to remove once theyhave contaminated a water supply.Many occur naturally in the earth’scrust (geological), such as arsenic,fluoride, and radionuclides. Otherpotential sources of contaminationinclude failures in septic tanks,sewer systems and municipallandfills; pesticides and fertilizersspread on cropland and lawns;highway salt; and industrial andmunicipal wastewater facilities thatdischarge into surface waters.Poorly constructed or improperlyabandoned wells provide pathwaysfor contaminants to enter aquifers.

Unless managed properly, all of thesesources have the potential to pollute.

RegulationsConcern about the quality of

the nation’s drinking water suppliesprompted the Safe Drinking WaterAct legislation in 1974. The EPA isauthorized to design nationalstandards that are the primaryresponsibility of the states to enforce.The Safe Drinking Water Act has hada significant effect on improvementsin both water quality and watersupply management. Increasingconcerns with toxins in the drinkingwater led Congress to amend the

Examples ofhealth risks fromthe tap.

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original Act in 1986, making itstricter and more inclusive.

National Drinking WaterStandards

The Safe Drinking Water Acthas two parts. First, EPA is toestablish National Primary DrinkingWater Regulations for drinkingwater quality. Generally thesestandards are numerical criteria foreach contaminant that may be foundin a drinking water supply and thatmay have an adverse effect onhealth. Drinking water standardsestablish maximum contaminantlevels, the highest allowableconcentration of a contaminant indrinking water. The maximumcontaminant levels are determinedthrough risk assessment proceduresthat take into consideration healtheffects, treatment technologies,sampling techniques, monitoringrequirements, and appropriatemanagement practices. Maximumcontaminant levels are usuallyexpressed as milligrams per liter(mg/L), which are equivalent to partsper million, since one liter of asubstance contains one millionmilligrams.

Under certain conditions, EPAmay designate that a treatmenttechnique be used in place of amaximum contaminant level. TheSurface Water Treatment and Leadand Copper Rules require a treatmenttechnique instead of a maximumcontaminant level.

Monitoring SuppliesThe second part of the Act

pertains to water suppliers. Theoperators of the 200,000 publicwater systems in the country willmonitor the quality of the waterdelivered to consumers and treat that

water if necessary to assure that theconcentration of each contaminantremains below the acceptable levelsestablished by EPA.

Monitoring requirementsdiffer according to whether thesystem is a community or non-community supply. Community andregional water supplies are devel-oped, owned and operated byvarious government agencies orprivate groups. Other commercialconcerns, such as trailer parks orhospitals often supply water as anancillary service. These suppliersmust meet some or all of the federaldrinking water regulations.

New RequirementsThe 1986 Amendments

greatly extended federal, state andlocal responsibilities for protectionof community water supplies. Waterutilities must provide the necessaryfacilities, personnel, and operatingvigilance to assure delivery of anadequate supply of safe water thatconsistently meets the requirementsof the National Primary DrinkingWater Regulations. In addition, theyhave various decision-makingresponsibilities beyond directoperation and maintenance. They aresubject to increased public scrutinysince the public must be notified ofeach drinking water violation, andthey are subject to more frequent andlarger fines for violations.

Drinking water standardsmust be met in the near future for108 contaminants, which includebiological contaminants, pathogenicbacteria, viruses, protozoa, etc.; lead;radionuclides; by-products ofdisinfection; organic chemicals; andnitrates and other inorganicchemicals. Monitoring will also berequired for a number of unregulatedparameters. Monitoring requirements

A community wa-ter supplier is autility that pro-vides drinking wa-ter to 25 or morepeople. There arejust under 60,000community watersuppliers, but onlyabout 250 ofthese suppliersserve populationsof 100,000 ormore. Non-com-munity drinkingwater suppliers —motels, resorts,restaurants andsimilar establish-ments, numberabout 140,000and serve non-residential users.

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Protection Programs - The Safe Drinking Water Act provides several programs that establishenvironmental safeguards to prevent contaminants from reaching water sources.•To assess and protect ground water sources:

Wellhead Protection Program - identifies all potential contamination sources within anarea surrounding a community water supply well.

Sole Source Aquifer Demonstration Program - prescribes a comprehensive land manage-ment plan that can be used to eliminate activities that have an adverse impact on public healthand ground water within the area surrounding a community supply well.•To protect surface water supplies:

Watershed Control Program - restricts activities that have the potential to contaminate sur-face waters. The goal of the program is to preserve and improve raw water quality by identify-ing and controlling contamination sources in the watershed.

Tub from an oldwashing machinewas used to filterlarge particles froma very smallcommunity drinkingwater supply. TheSafe Drinking WaterAct, asreauthorized, setsrequirements forfiltration that cannotbe met with suchhomemade devices.

Research StrategyAs a result of amendments to

the Safe Drinking Water Act, EPAestimates that more than 6,000 watersystems will have to install watertreatment to meet the proposedstandards for organics andinorganics, 11,000 systems will beaffected by filtration requirements,and 43,000 systems must addresscorrosion control alternatives.

Under the Safe DrinkingWater Act, water utilities, EPA, andstates have enormous responsibilities.The agenda for EPA to establish,states to regulate, and utilities to

for each contaminant are quitespecific, and water systems mustfollow a prescribed schedule andprocedure for contaminant samplingand analysis. However, states havethe authority to waive monitoringrequirements for many contami-nants if those substances have neverbeen used in an area or if watersystems are not vulnerable tocontamination by the substance.

Best Available TechnologyThe regulations designate the

best available technology for eachcontaminant exceeding standards tobring drinking water systems intocompliance. The best availabletechnologies are intended to assistEPA in establishing maximumcontaminant levels by taking intoconsideration the various treatmenttechnologies available, their costand efficiency for removingcontaminants from water, and to aidwater utilities in selecting appropri-ate treatment methods to meetdrinking water standards.

The ORD provides support-ing information on performance andcost of treatment technologies formaximum contaminant level or ruledevelopment.

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Risk Reduction Engineering LaboratoryMuch of EPA’s drinking water research is conducted by ORD’s Office of Environmental

Engineering and Technology Demonstration at the Risk Reduction Engineering Laboratory’sDrinking Water Research Division in Cincinnati, Ohio. This staff has provided leadership indrinking water research for several decades. Their work in microbiological treatment and ininorganics and organics control has contributed significantly to advancing the state of thescience in these areas.

Through a multidisciplinary program, integrating chemistry, engineering, microbiology,and economics, drinking water research is conducted to establish practices for the control andremoval of contaminants and for prevention of water quality deterioration during storage anddistribution. This research is directed toward improving chemical removal methodologies,controlling disinfection by-products, evaluating disinfection processes, and providing technicalassistance to states and municipalities in adopting and implementing drinking water standards.In-house pilot plant treatment facilities aid the testing and evaluation of new and emergingtechnologies for potential real-world application.

This Laboratory, in support of EPA’s National Water Program, is concentrating much ofits effort exploring new or improved and more affordable technologies for small communities.

meet a multitude of regulatoryrequirements will demand solutionsto many new and complex problems.

Small SystemsTo bring small community

systems into compliance willnecessitate some new thinking andflexibility in terms of technologyapplications and institutionalarrangements. Treating 50,000gallons per day is not simply amatter of downsizing to one percentof a 5-million-gallon per day plant.Operator ability, capital resources,and extremes in water quality mustbe taken into account.

The treatment needs of smallutilities often are not clear. Pilottesting programs to evaluatetreatment processes and operationson a small scale contribute signifi-cantly to final system design andsuccess. The innovative applicationof proven techniques and technolo-gies in individual plants and units

may provide solutions to most smallcommunity water quality problems.

Package Plant SystemsThe most significant require-

ments for small systems are lowconstruction and operating costs,simple operation, adaptability topart-time operations, and lowmaintenance. To meet these needs,the less costly package plant systemspresent an attractive alternative tosmall custom designed centraltreatment systems. The differencebetween package plants and customdesigned plants is that packageplants arrive on site virtually readyto operate.

Most of the technologies usedin custom designed treatment plantsfor community water systems can beused in package plants and hometreatment units. These technologiesare applied to reduce levels oforganic contaminants and controlturbidity, fluoride, iron, radium,

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Ultrafiltration membrane package plant undergoing tests atEPA’s Test & Evaluation Facility in Cincinnati, OH.

arsenic, nitrate, microorganisms andmany other contaminants. Aestheticparameters such as taste, odor, orcolor also can be improved.

Researchers in ORD areworking to provide an analysis ofpackage plant treatment systems todetermine performance, costs,reliability, and capability. A greatdeal of this effort is focused onencouraging industry to design andmake prefabricated small treatmentplants suitable to the sizes andvarious treatment needs of smallcommunities. Prefabrication meanslower on-site construction costs. Tocomplete this work, ORD willcreate and demonstrate hybridpackage plant designs and configu-rations.

Operation and Maintenance

Through a cooperative effortwith the American Water WorksAssociation (AWWA), ORD hasbeen examining the broad applica-tion and use of package plantsacross the country. This study,

Package Treatmant PlantsPackage plants are treatment units that are assembledin a factory, mounted on a skid, and transported to thetreatment site, or alternatively, transported as compo-nent units to the site and then assembled. They arecurrently most widely used to treat surface watersupplies for removal of turbidity, color, and microbeswith filtration processes. However, most treatment tech-nologies are adaptable to package plant design andconfiguration.

Design criteria and operating and maintenance re-quirements can vary widely. Thus, there is a need to de-velop reliable data and knowledge of package plant sys-tems to enable development of appropriate guidance onselection criteria.

The ORD is working with plant manufacturers totest different package plants at their Test and Evaluation(T & E) Facility, located in Cincinnati, Ohio. The plantsto be tested focus on disinfection and removal oforganic material to improve the disinfection process,since this is the area of greatest concern and subject ofthe pending Disinfection/Disinfection By-Product andSurface Water Treatment Rules. In addition, alternativedisinfectants will be tested via a nearly full-scale pipeloop system to evaluate water quality as it is delivered tothe tap through the distribution system.

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Point of Use Treatment Unit Point of Entry Treatment Units

Home Treatment Units

Home treatment units can be an alternative to centralized treatment technology for indi-vidual and small systems. Such systems have been widely adapted to treating water from asingle faucet at the point of use or for the entire house at the point of entry. Their off the shelfavailability makes them attractive alternatives. Very small systems may find point of entry unitsless costly to buy and easier to install and maintain than a custom designed or package plant.For example, a responsible party at a Superfund site in Pennsylvania opted to install 15 pointof entry units to remove trichloroethylene at individual homes rather than install a distributionsystem connecting each home to another community’s network several miles away. The long-term future cost of monitoring, maintenance, and sampling was preferable to the high one-timecapital cost of installing a distribution system.

Point of entry treatment is acceptable as an available technology for complying with drink-ing water regulations under certain circumstances. Until recently, point of use treatment unitswere acceptable only for interim measures, such as a condition for obtaining a variance or ex-emption to avoid reasonable risk to health before full compliance can be achieved. An EPA re-search study is evaluating point of use units to reduce naturally occurring ground water fluorideto acceptable levels for a community of 40. It is expected that these units may be acceptablefor compliance in some communities in the future.

Neither point of use nor point of entry is designated as a best available technology be-cause of the difficulty in monitoring the reliability of treatment performance and controlling per-formance in a manner comparable to central treatment. All public water supplies must monitorand ensure the quality of water treatment, whether they provide central treatment or decentral-ized treatment through point of use/point of entry units. State approval is required for use ofsuch units.

Both systems are available from a large number of manufacturers and most treatmenttechnologies can be adapted to home devices. In certain situations, point of use/point of entryunits can be cost-effective solutions when a very small community cannot afford central treat-ment for removal of a contaminant, such as an organic chemical or fluoride. For example, withstate approval, several small communities (25 to 200 people) in Arizona installed home sys-tems using activated alumina to remove fluoride. A manufacturing/engineering company oncontract with one community maintains all the systems.

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which evaluated water treatmentfiltration procedures at 48 smallsystems, found that, in addition to alack of proven technology, thesuccess or failure of a plant is oftendependent on its financial status.

If a community fails torecognize the need for training andcertification for operators inspecific treatment processes,professional guidance and technicalassistance in system selection, andadequate funding for operation andmaintenance, system operation andwater quality will suffer.

According to the study, anoperator’s technical ability andavailability to perform the job arecrucial to successful operation ofthe system. Additionally, frequencyof and accessibility to training areprincipally responsible forimprovement in water treatmentperformance.

Because of limited revenues,very often only part-time operatorscan be hired by small communitieswith little funding available fortraining and certification. Smallsystems normally do not have alarge pool of trained engineers andscientists to deal with complexequipment or with constantlychanging treatment needs. Inaddition, the small system mighthave difficulty attracting skilledstaff because of economic con-straints.

The ORD is investigating theutility of a telemetry system inwhich the package plant treatmentsystem can be remotely monitoredand operated. This approach, calleda Supervisory Control and DataAcquisition system, could aid in thedevelopment of an electronic“circuit rider” that would provideservice and guidance simulta-neously via long distance to several

Looking Ahead

Results of the recent ORD/AWWA evaluation ofpackage plants identified several technical issues thatrequire further investigation for resolution.• As in systems of all sizes, the conflicting objectivesbetween minimization of disinfectant by-productformation and maximization of water quality (througheffective microbe reduction) are a major concern forsmall systems. Often, small systems may use extrachlorine just to "make sure" the water is safe,microbiologically, only to result in higher rates of disin-fectant by-product formation. This in turn, may increasethe risk to the community of exposure to undesirable orharmful chemicals.

In other cases, package plants, because of theirshort disinfectant contact times with water flowingthrough the treatment train, may not allow sufficient timefor the disinfectant to be effective. This is especially truefor small streams that exhibit highly variable waterquality because of storms and runoff, which require achange in treatment or chemical feed rates. Thus,disinfectant by-product formation may be low, but so isdisinfection efficiency.• In theory, the treatment technologies utilized inpackage plants and small systems can provide potablewater and achieve reductions in Giardia lamblia cysts(99.9%) and viruses (99.99%), as required by the Sur-face Water Treatment Rule. However, there are littlefield data to verify this assumption.• Successful operation of surface water treatmentfacilities may require a more sophisticatedunderstanding of water chemistry and engineeringprinciples than was traditionally believed necessary.Operators may need more advanced training than istypically provided. Remote monitoring and circuit riderapproaches may be especially important in effectivelyleveraging the services of a qualified, fully capableoperator.

systems that cannot individuallyafford a trained operator.

Research Activities

Meeting Biological StandardsRisk

Approximately 200,000 casesper year of gastroenteritis will be

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Microorganisms called coliforms are present in watercontaminated with human and animal feces. Althoughcoliforms do not usually cause disease, their presencein drinking water indicates that disease-causingorganisms may be present. If a water sample is passedthrough a filter, coliform bacteria present in the sample

are retainedand, underspecific testconditions,develop intogolden sheencolonies.Watersamples thatcontaincoliforms aretested furtherto ensure thata water supplyis safe todrink.

Number of systems in violation (by system size)

avoided as a result of filtration anddisinfection.

Small systems have the mosttrouble meeting EPA’s standards forsafe drinking water. Small systemsaccounted for almost 87 percent ofthe 5,400 systems with maximumcontaminant level violations in 1991.Microbial violations accounted forthe majority of these cases, putting12 million people at risk.

Although fatal waterbornediseases are no longer a major publichealth threat in the U.S., there arestill thousands of water-relatedpathogen-induced cases of illness,characterized by vomiting anddiarrhea, reported annually.Fortunately, disinfection andfiltration processes can eliminate thecause of such illnesses, and theDisinfection Rule will require allsystems to meet new microbiologicalstandards.

The principal immediate riskfrom drinking water contaminationis still biological in origin withverified outbreaks of waterbornediseases caused by lack of propertreatment facilities or a breakdownin such equipment. Throughout mostof recorded history, human organicwaste has posed the greatest threat tosafety of drinking water. Typhoid,cholera, and other waterborneinfectious diseases could not be fullyconquered until disinfection andfiltration treatment processes wereadopted.

TreatmentAt a minimum, the treatment

required to control microbiologicalcontamination must includedisinfection to kill disease-causingorganisms. The Surface WaterTreatment Rule also requires surfacewater systems to install some formof filtration (the process of removingsuspended solids that cause

Population served by community systems in violation(by contaminant group)

Very Small 3,54465.6% Small 1,148

21.3%

Medium 3576.6%

Large 3366.2%

Very Large 150.3%

Microbiological 12,000,000

Radiological 300,000

Inorganics 400,000

Organics 900,000

Turbidity 5,100,000

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A communitydrinking watersupply, servingabout 25 homes,flowed to this tankfor treatment bychlorination andaeration. Due toregulatoryrequirements of theSDWA, asamended, this jerry-rigged system wasno longer adequateto insure a safewater supply and,thus, was recentlyreplaced by anultrafiltrationpackage plant.

Example of a small community "homemade” system thatprovides no adequate assurance that drinking water is safe.This drinking water supply intake structure is placed in a streambed, surrounded by mud, moss, gravel and water.

turbidity) unless criteria forexemptions can be met. (Turbidityis a measure of the cloudiness ofwater caused by the presence ofsuspended matter. Turbidity can becaused by many things, includingthe presence of microorganisms,which can interfere with disinfec-tion effectiveness.) These treatmenttechnologies and standards formicrobes, coliforms, and arequirement that all systems beoperated by qualified operators,expand control of disease-causingmicrobes.

Concern has recentlymounted over the ability of certainpathogenic protozoan(Cryptosporidium) cysts to survivetreatment processes and, thus, enterthe distribution system. Researchersare designing and testing filtrationtechniques to physically remove thecysts. Slow sand, diatomaceousearth, coagulation/rapid sandfiltration, bag filtration, andmembrane processes are beingstudied.

ResearchMany small communities

across the nation are seekingsolutions to financing basicdrinking water treatment. Twosmall communities in WestVirginia, like thousands of othervery small towns across the countrywith central systems (at least 15service connections serving 25people) distribute water from theonly available source in the area.One town delivers untreated waterfrom a cave; the other deliversminimally treated water from acollapsed mine shaft. Both sourcesare from unprotected aquifers.Escherichia coli, a bacteriumindicating fecal contamination, andother microbiological contaminantswere detected in both source waters

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Precast manholes placed in the left side of the stream serve asdrinking water intake structures for a very small communitysupply. Water is distributed directly to customers via theoverhead hose attached to poles.

New ultrafiltration membrane package plant located by LakeHavasu.

and in one of the distributionsystems.

The Chemehuevi Indian Tribeof Lake Havasu, California,distributes water from that lake to400 people. Although raw waterquality is generally good, because ofintense recreational use in thesummer, compliance with theSurface Water Treatment Rule isdoubtful.

A sportsman camp inLakeville, Maine, serves five cabinsand a transient population ofapproximately 30 people dailythroughout the hunting and fishingseasons. The water supply from thelake is adversely affected by erosionfrom clear-cut logging within itswatershed. Soil and silt buildup andsignificant algae growth havealready damaged nearby lakes,rendering them incapable ofsustaining wildlife.

Disinfection is a basicrequirement for each of thesesystems. Filtration to removesuspended solids also is a require-ment for the surface water source.The ORD is working with thesecommunities to conduct research onpackage plant systems to see if theyare capable of meeting regulatoryrequirements for microbiologicalcontamination under different watersource and geographic conditions.

Ultrafiltration membranepackage plants are installed in two ofthese community central systems toprovide filtration plus disinfection.Data from monthly sampling ofmicrobiological contaminants willdetermine the plants’ capabilities toperform throughout changes inseasonal weather and raw waterquality. Other analyses will be donethroughout the system for disinfec-tion by-products and toxic chemi-cals.

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Meeting Organic Chemical

Standards

Risk

Approximately 30 cancerdeaths per year will be avoided ifall water supplies lower vinylchloride concentrations below0.002 mg/L.

Approximately 72 cancerdeaths per year will be avoided ifall water supplies lower ethylenedibromide concentrations below0.00005 mg/L.

While microbiologicalcontamination primarily producesinfectious diseases, chemicalpollutants can contribute to chronictoxicity or cancer. Drinking watersources can be selected that are freeof significant microbiologicalcontaminants or protected frompotentially harmful contaminants ofhuman origin, but these samewaters are vulnerable to a variety ofchemicals usually related topollution discharge or treatment.Ground water in the vicinity ofimproperly designed waste disposalsites often has been found to beheavily contaminated by migratingtoxic chemicals.

Many synthetic organicchemicals, compounds that containcarbon, have been detected in watersupplies in the U.S. Some of these,such as the solvent trichloroethyl-ene, a carcinogen (an agent that canincite malignant tumor growth), arevolatile. They easily become gasesand can be inhaled in showers orbaths or while washing dishes.They can also be absorbed throughthe skin.

More than 60,000 toxicchemicals are now being used byvarious segments of industry andagriculture. These substances range

from industrial solvents andpesticides to cleaning preparationsand degreasers. When used ordiscarded improperly, these chemi-cals pollute ground and surfacewaters used as sources of drinkingwater.

Technology and operatingprocedures are available to preventrelease of many contaminants orcontrol them in drinking water.However, costs can be substantial,especially for small systems, becausethey cannot benefit from economiesof scale.

TreatmentThe technologies most suitable

for organic contaminant removal insmall systems are granular activatedcarbon and aeration. The carbon pro-cess has been designated as the bestavailable technology for syntheticorganic chemical removal, andpacked column aeration, as best forvolatile organic chemicals. Thegraular activated process uses carbonthat has been treated to make it ex-tremely porous so that it can removeorganic contaminants through ad-sorption.

Aeration, also known as airstripping, mixes air with water tovolatilize contaminants. Thecontaminants are either releaseddirectly to the atmosphere or aretreated and then released. Aeration isused to remove volatile chemicals.

ResearchOrganics control has been a

focus of drinking water research formore than twenty years. Thepioneering work contributed by ORDto this field has provided newtechnologies and methodologies forthe standard-setting process,benefiting not only small communi-ties but the entire drinking watercommunity.

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100

50

25

20

15

10No. of Houses

200

400

600

800

1000

1000

1200

1400

1600

1800

2000

POE Cost

10000 50000Length of Pipe in Connection (ft.)

Cost of POE vs. Cost ofConnecting to a Central System

Recent studies have beencomparing cost and performance ofsmall systems (point of entry andcentralized treatment technology) forremoval of organic contaminants.Whole house, point of entrytreatment units may provide anattractive alternative to centralizedtreatment technology, since costs forinstalling a new distribution systemwith central treatment or connectingto a distant water supply may beprohibitive. Conversely, withdistribution systems in place, pointof entry is not likely to be a viablealternative, except for the smallestutility, one that is unable financiallyto build a new central treatmentplant, or a community with multiple

source waters contaminating only aportion of the distribution system.

Various Superfund sites aswell as states have been employingpoint of entry systems for severalyears in remediation programs. Thepredominant contaminants beingremoved in point of entry applica-tions are chlorinated solvents,petroleum products, aldicarb,ethylene dibromide, and radon.Treatment technologies such asgranular activated carbon, aeration,reverse osmosis, ion exchange andozone/ultraviolet light have beenwidely adapted to treating water forthe entire house. The removalefficiencies provided by thesevarious systems range between 86and 99+ percent.

Cost depends on systemcapacity and type of contaminantsbeing removed. For organicchemical contamination in the watersupply of a small community,granular activated carbon treatmentis needed. The cost-effectiveness ofa central system is in part a functionof the number of householdsinvolved, total length of pipe andpumping required for connections,size and economics of the existingcentral plant, and additionaltreatment required by the centralplant.

The figure above showsannual household costs of point ofentry systems and those of centralwater supply as a function of thetotal length of pipe and componentsrequired for connection of thespecific number of homes involved.The cost trade-offs indicate that ifthe average length of new distribu-tion components required forconnection to central supply perhouse are significantly greater than200 feet, then point of entry may bea cost-effective alternative.

Cost of Point ofEntry Units vs. Costof Connecting to aCentral System.

Cos

t $/Y

ear/

Hou

seho

ld

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Meeting Disinfection

By-Product Standards

Risk

Millions of people may beexposed to trihalomethanes in theirdrinking water at levels above 0.10mg/L, resulting in approximately 50cancer deaths annually.

A wide variety of chemicalsare added to drinking water toremove various contaminants.Among them are alum, iron salts,chlorine and other oxidizing agents,all of which may leave residues orpotentially hazardous by-productsin the finished water. In fact, themost common source of syntheticorganic chemicals in treateddrinking water is the interaction ofchlorine or other disinfectants withthe naturally occurring particlesfound in the water.

Chlorine, the majordisinfectant used in treatment plantsto purify water supplies, canundergo complex chemicalreactions when mixed withcontaminated water. In the 1970s,scientists at EPA discovered thatchlorine can react with natural andman-made chemicals in water tocreate by-products known astrihalomethanes. At least one ofthese by-products, chloroform, iscarcinogenic in animals. Otherdisinfectants also have been foundto generate undesirable by-products.The establishment of a maximumcontaminant level for totaltrihalomethanes (chloroform,bromoform, bromodichloro-methane, and dibromochloro-methane) will control thesedisinfection by-products. Futureregulation of compounds such ashaloacetic acids will controladditional disinfection by-products.

TreatmentIn general, disinfection by-

products are difficult and costly toremove from drinking water oncethey have been formed. It is better toremove the natural organic matterprior to disinfectant addition.

From an economic standpoint,alternative disinfectants should be nomore expensive than chlorine.Unfortunately, since no singleexisting alternative disinfectant, suchas ozone, chlorine dioxide, chloram-ines and ultraviolet radiation, cansatisfy all requirements (effective,inexpensive, and can provide adisinfectant residual in the distribu-tion system to prevent regrowth ofmicroorganisms), a combination ofalternative disinfectants is needed.Though such a strategy can be usedto reduce trihalomethanes and totalhalogenated organic by-productlevels, the combined use of thesedisinfectants will produce otherdisinfectant by-products.

Several strategies for minimiz-ing harmful chlorination by-productsare used by small systems:

1) Reduce the concentration oforganic materials before addingchlorine. Water clarificationtechniques, such as coagulation,sedimentation, and filtration, caneffectively remove many organicmaterials. Activated carbon may beused to remove organic materials athigher concentrations or those notremoved by other techniques.

2) Reevaluate the amount ofchlorine used. The same degree ofdisinfection may be possible withlower dosages.

3) Change the point wherechlorine is added. If chlorine ispresently added before treatment,instead it can be added afterfiltration, or after chemical treatment.

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4) Use alternative disinfectionmethods. Ozonation and ultravioletradiation, the alternative methodsmost practical for small systems,cannot be used as disinfectants bythemselves. Both require a secondarydisinfectant (usually chlorine) tomaintain a residual in the distributionsystem.

ResearchResearch activities include

studies on the maintenance ofmicrobial quality of treated drinkingwater while minimizing theformation of disinfection by-products. Any changes that are madein drinking water treatment must bemade in such a way that themicrobial safety of drinking water ismaintained. Research studies arefocusing on the use of disinfectantsother than chlorine and removal ofprecursor material by enhancedconventional treatment, granularactivated carbon, and membranes forcontrolling disinfection by-products.

In Jefferson Parish, Louisiana,and Evansville, Indiana, work is inprogress that can be applied to smallsystems. Mutagenicity data are beingcollected together with physical andchemical performance data tocharacterize the operating parametersfor a series of treatment processes. Apilot column system will be operatedto assess seasonal variations with anoverall objective of comparing theeffects of ozonation and variousfilter media in reducing ozone by-products and stabilizing water.

Other field work focuses onan integrated ozone-bioreactor sys-tem with the objective of chemically/microbiologically transformingprecursors to less reactive and lessproblematic by-products. Otherinvestigations focus on the use ofchlorine dioxide in conjunction witha reducing agent to eliminate the

metabolites, chlorite and chlorate,while controlling disinfection by-products. Membrane treatmentresearch is evaluating the potentialrole of nanofiltration and reverseosmosis in removing by-productprecursors from drinking water.

Meeting InorganicContaminant StandardsRisk

Many potential drinking watercontaminants are of natural origin.There may be inorganic contami-nants, such as common salts, ortrace toxic substances like radiumand radon. Nitrates, common inagricultural areas, can cause adisorder in infants (“blue baby”syndrome) that affects the ability ofthe bloodstream to carry oxygen.These health concerns are generallyassociated with failure to protectoriginal water sources.

Some other inorganiccontaminants are from localizedgeologic deposits of arsenic orselenium. Arsenic occurs naturallyas an impurity in various mineralsand in the ores of certain commer-cially mined metals. If untreated,arsenic exposure can cause liver andkidney damage.

Another natural contaminantcontrollable with modern technologyis fluoride. Many communities add itto their drinking water in regulatedamounts to improve dental health.However, excessive exposure to thisinorganic chemical, which is theseventeenth most abundant sub-stance in the earth’s crust, can causeskeletal damage, as well as abrownish discoloration of teeth.

TreatmentInorganic contaminants

presently regulated under the SafeDrinking Water Act include manymetals, such as arsenic, barium,

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cadmium, copper, lead, mercury,and nickel; other elements, such asasbestos and fluoride; and radionu-clides. Conventional treatment,coagulation/filtration (initialtreatment that convertsnonsettleable to settleable particles),can be used to remove someinorganics. Additional technologiesfocus on specific contaminants.

Separation processes, reverseosmosis and electrodialysis, use asemipermeable membrane thatpermits only water, and notdissolved ions (atoms that have anelectrical charge because they havegained or lost electrons), such assodium and chloride, to passthrough its pores. With reverseosmosis, contaminated water issubjected to a high pressure thatforces pure water through themembrane, leaving most contami-nants behind in a brine solution.The electrodialysis process employselectrical current to attract ions toone side of a treatment chamber.This process is effective inremoving fluoride and nitrate, andcan also remove barium, cadmium,selenium, radium, and otherinorganics.

Ion exchange units can beused to remove many ionic(charged) substances from water.Ion exchange works by exchangingcharged ions in the water for ions ofsimilar charge on an exchangemedium, usually a synthetic resin.In cation (a positively charged ion)exchange, the ions most oftendisplaced from the resin are sodiumions. For anion (a negativelycharged ion) exchange, the ionexchanged is usually chloride.

ResearchArsenic Removal

Water supply for the smallrural community of San Ysidro,

New Mexico, exceeded federaldrinking water standards for botharsenic and fluoride. This communitywith 200 residents and 80 homesreceives water of poor quality fromground water sources and hasdifficulty in providing centraltreatment. The water supply containsnaturally occurring arsenic, fluoride,and a high level of total dissolvedsolids.

Researchers embarked upon atwo-year study in 1988 to help thecommunity achieve compliance andevaluate removal efficiency, cost,and management effectiveness. Aninitial nine-month research studywith the Mobile Drinking WaterTreatment Research Facilitydetermined that the most cost-effective means of removing arsenicand fluoride from the water would bewith home treatment point of usereverse osmosis units.

The eighty under-the-sinkunits installed in homes loweredlevels of arsenic, fluoride, totaldissolved solids, chloride, iron, andmanganese to well below the federalstandards. The cost to the customerfor point of use treatment was lessthan half the estimated cost ofproposed central treatment. To assistcustomer responsiveness to newtreatment units, special ordinanceswere issued by the utility to addresscustomer and water utility responsi-bilities and liability issues, and torequire that the unit be installed inhomes obtaining water from theutility.

To assist small communitieswith water supplies that exceed themaximum contaminant levels forarsenic, ORD conducted a demon-stration project in four homes inAlaska and Oregon to evaluate pointof use systems. These homes weresupplied by private wells with water

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containing naturally occurringarsenic in concentrations rangingfrom 0.1 to 1.0 mg/L. The currentstandard for arsenic is 0.05 mg/L.

The pilot systems consisted ofan activated alumina tank, an anionexchange tank, and a reverseosmosis system. Both point of useand point of entry systems wereused. Results showed that all threetreatment techniques effectivelylowered arsenic concentrations inwater. The ion exchange units wereable to treat water containing asmuch as 1.16 mg arsenic/L.Additional research is needed toverify the results from the earlierstudy and to further define the costand performance characteristics ofthese units.

Nitrate RemovalAn extensive study was

sponsored by ORD in 1985 inGlendale, Arizona, where 10 of 31drinking water wells had been shutdown due to excessive nitrates. Thewater supply, containing 18 to 25mg/L of nitrate, was reduced to 7mg/L in a 1-million-gallon per dayplant, well below the existingmaximum contaminant level of 10mg/L.

This project (using the MobileDrinking Water Treatment ResearchFacility for initial work) tested thefeasibility and provided cost data forthree nitrate removal technologies:reverse osmosis, electrodialysis, andion exchange. Comparative costs forproducing 1,000 gallons of treatedwater in the 1-million gallon per dayplant were 30 cents for ion exchange,85 cents for electrodialysis, and onedollar for reverse osmosis.

To obtain detailed informationon design, operation, performance,and cost for removing nitrate by ionexchange, ORD sponsored a two and

a half year study at a 1-milliongallon per day plant in McFarland,California, in 1985. The plant treatsclose to 700 gallons of ground waterper minute. Data showed that thefacility reduced nitrate levels to wellbelow the maximum contaminantlevel of 10 mg/L. Researchers alsofound that if the well was continu-ously pumped, the need for nitratetreatment decreased. Maximumautomation was used successfullywith minimum staffing, which istypical for a small water systemoperation. Additional research isneeded to verify the conceptsestablished during this study andshould focus on alternative brinedisposal techniques, as well as theconcept of operating small treatmentplants on an automated basis.

Meeting RadionuclideStandards

RiskRadionuclides, which are

known human carcinogens, exist inwater supplies serving as many as100 million people.

Radionuclides found indrinking water are members of threeradioactive series, uranium, thorium,and actinium and include thenaturally occurring elements radium,uranium, and the radioactive gas,radon. These radionuclides are foundin drinking water supplies through-out the U.S., but certain geographicareas have particularly high levels.

Different types of ionizingradiation emitted by these contami-nants may cause different levels ofbiological damage. Radium, wheningested, concentrates in bone andcan cause cancers. Ingested uraniumcan cause cancers in bone and canhave a toxic effect on kidneys.

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EPA Mobile Drinking Water Treatment Research FacilityFor over a decade, EPA’s Risk Reduction Engineering Laboratory has sponsored the op-eration of a transportable, reusable, pilot-plant facility for inorganic contaminant removal.This pilot plant is particularly applicable to the diverse inorganic contamination problems insmall communities. The plant is housed in a 10- x 40-ft. trailer that can be transported to asite to study treatment technologies applicable to a given contaminant removal problem.An estimated several thousand public water supplies in small communities in the U.S.contain inorganics that can be removed by advanced water treatment processes, such aspacked beds of activated alumina, ion exchange resins, or by separation using reverseosmosis or electrodialysis. Where reliable design criteria and economical operating proce-dures are not available for the selection, cost-effective application, and safe operation ofthese processes, the mobile facility, built and operated by the University of Houston, canbe transported to a site for water treatment process research and analysis.

Radon, a colorless, odorless,tasteless gas, poses uniqueproblems. The gas, a decay productof uranium deposits, enters homesdissolved in drinking water;however, when the water is heatedor agitated in a shower or washingmachine, it becomes a breathabledrinking water contaminant thatmay, in the opinion of scientists,greatly increase the risk of lungcancer. Removal of radon-222,radium-226 and -228 and uranium,all of which are carcinogenic, are inthe proposal stage for regulation bythe Safe Drinking Water Act at 300

pCi/L (picocuries per liter), 20 pCi/L,and 20 µg/L (micrograms per liter),respectively. Picocuries per liter is ameasure of the concentration of aradioactive substance. A level of 1pCi/L means that approximately twoatoms of the radionuclide aredisintegrating per minute in everyliter of water.

TreatmentToday’s treatment techniques

also are effective against radionu-clides. Reverse osmosis is effectivefor treating several radioactivecontaminants in drinking water. Ion

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exchange can be used to removeradium and uranium. Radon removalrequires use of granular activatedcarbon or aeration techniques. Eachof the treatment processes forremoving radionuclides fromdrinking water generates waste thatmust be handled and disposed withcare.

ResearchUranium Removal

Uranium-contaminateddrinking water is a commonproblem, particularly in the westernU.S. Approximately 100 to 200community water supplies treat theirwater to reduce uranium levels toconcentrations that meet federalregulations.

Removal of uranium fromground water supplies in NewMexico and Colorado was demon-strated in studies by ORD to bothreduce levels that were 20 times theproposed maximum contaminantlevel and to determine operatingcharacteristics, costs and uraniumtreatment waste disposal options.Four ion exchange columns, housingthree different types of resins, werepilot-tested in New Mexico and afull-scale ion exchange system wasevaluated in Colorado.

Results showed that anionexchange can remove more than 99percent of the uranium present inraw water at reasonable cost.Disposal of uranium-laden wastewa-ter was a complex task because ofthe sophisticated sample analysesrequired. Operation and maintenancecosts for such removal systems willbe high. The removal efficiency ofthese units is very much a functionof the source water matrix. Addi-tional research is needed to definethe removal characteristics of theseunit processes as a function of source

water characteristics. The generalcost and performance of these unitprocesses also must be verified.

Radon RemovalAeration and granular

activated carbon treatment to removeradon have been demonstratedextensively as highly effective(greater than 90 percent removal)and reliable. ORD participated in astudy to analyze a large body ofperformance data to determine theeffectiveness of home treatmentunits to remove radon from drinkingwater. Point of entry granularactivated carbon units were installedat 122 sites in 12 states by Lowry etal. to treat ground water supplieswith varying quality characteristics.

The treatment units weresingle vessels containing 1 to 3 cubicfeet of granular activated carbon.Most units were installed down-stream of an existing pressure tankand were operated under existingwater pressure in the home. Ingeneral, the only maintenancerequired was twice-yearly replace-ment or washing of the sedimentfilter. Researchers concluded that atypical point of entry granularactivated carbon unit may last adecade.

Researchers also havedemonstrated that low cost/lowtechnology aeration techniques canbe applied easily in small communi-ties to significantly lower radonconcentrations in drinking water. Ata 33-home trailer park in NewHampshire, removal of 60 to 87percent was achieved with simpleaeration and by retaining water in astorage holding tank for nine hoursto allow for decay of radon. Betterthan 95 percent removal wasobserved by increasing retentiontime to 30 hours, also with aerationapplied.

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Average totaluranium concentra-tions in publicground watersupplies.

To compare three types ofpoint of entry treatment systems forremoval of radon, researchersevaluated granular activated carbon(with and without ion exchangepretreatment) and two types ofaeration devices, diffused bubbleand bubble plate. The granularactivated carbon unit proved to bethe easiest to operate and maintainand the least expensive. Radonconcentrations were alwaysreduced, but not necessarily at thesame rates. Waste from the systemmay require special handling anddisposal. The aeration systems werevery efficient in removing radon;however, they were more suscep-tible to operational problems.Comparative studies are needed tofurther define the most efficienttype of unit process for proposedmaximum contaminant levels andunder various source waterconditions.

Radium RemovalMore than 175 cities in the

Midwest deliver drinking water thatcontains radium in concentrationsthat exceed proposed federalstandards. To assist small communi-ties with compliance, ORD investi-gated several treatment methods toremove radium economically fromdrinking water.

A study in Iowa evaluatedpossible economical ways to removeradium from drinking water bytypical iron removal plants. Thestudy found that sorption of radiumto manganese oxides could possiblybe exploited to remove radium, andthat filter sand was able to sorbsignificant concentrations of radiumat typical hardness concentrations, ifthe sand is periodically rinsed with adilute acid.

Researchers, over a two-yearperiod, also evaluated a system toremove radium from ion exchange

pCi/L

0.00 - 1.99

2.00 - 4.99

5.00 - 9.99

10.00 - 19.99

> 20.00_

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pCi/L

0.00 - 99.99

100.00 - 199.99

200.00 - 499.99

500.00 - 999.99

> 1000.00_

Average radon-222(Rn-222) concentra-tions in publicground watersupplies.

waste at a small water treatmentfacility in Redhill Forest, Colorado,where raw water comes from deepwells and contains naturallyoccurring radium, radon and iron.The treatment system consisted ofaeration to remove radon gas andcarbon dioxide, chemical clarifica-tion to remove iron and manganese,and ion exchange to remove radiumand reduce “hardness” or pH level. Aseparate system removed onlyradium from the regeneration water(brine) of the ion exchange processby permanently complexing it on aradium selective complexer resin.This treatment was found to be veryefficient in the removal of radiumfrom the ion exchange processwastewater.

Full-scale application ofradium adsorption onto MnO

2-coated

filters was tested at several smallpublic water systems in NorthCarolina. The filter tests showed thatfor hard water (pH=7.4), total radium

removal was 14,200 pCi/g MnO2

before the maximum contaminantlevel was exceeded. For softer water(pH=4.5), total radium removal was5,000 pCi/g MnO

2 before the

maximum contaminant level wasexceeded. The filters also canremove low concentrations ofcadmium, calcium, cobalt, cesium,iron, and manganese. Future work inthis area is needed to define cost-effective treatment technologies forremoving radium with specialemphasis on residual disposal.

Meeting CorrosionBy-Product StandardsRisk

Millions of people may beexposed to lead, resulting inpotential risk of central andperipheral nervous system damage,particularly to infants and fetuses.

Exposure to excessive levelsof lead and copper in drinking wateris primarily caused by corrosion

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the water is not moving, generallyovernight or other times when thewater supply is not used for severalhours at a time. The first water thatcomes from the faucet after longperiods of no use may have lead in it.Future use of lead pipe and leadsolder has been banned. Newstandards for lead and copper willrequire treatment of water to inhibitcorrosion and the leaching of leadfrom the distribution system.

In many areas of the U.S.,homeowners and small water supplysystems use water that is potentiallycorrosive to metallic materials(copper, lead, and zinc) in thedistribution system. Corrosion canbe caused by the use of minimallyacidic waters (low pH or alkalinity)and concentrations of dissolvedsolids. Health problems can resultfrom ingestion of corrosion by-products, aesthetic quality of thewater can decline, and costs due topiping system deterioration may rise.

Average radium-226 (Ra-226)concentrations inpublic ground watersupplies.

_

pCi/L

0.00 - 0.49

0.50 - 0.99

1.00 - 1.99

2.00 - 4.99

> 5.00

resulting from the contact ofcorrosive water with these materialsfound throughout water distributionsystems and in the plumbing ofprivate homes. Of particularconcern is the presence of leadservice lines and connections, leadpipes in the home, and lead solderthat is less than five years old. In1986, EPA estimated that as manyas 42 million people in the U.S.may be exposed to water lead levelsin excess of 20 µg/L. In homes lessthan five years old that contain leadsolder, it is not uncommon to findwater lead levels in excess of 100µg/L. The most cost effective wayto prevent lead and coppercorrosion by-products and reducethe risks posed to human health andthe environment is throughcomprehensive corrosion reductioncarried out by water suppliers.

Where lead is present inpipes and soldered connections, thelead dissolves into the water while

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responsible for the uptake of leadand copper in drinking water;developing chemically-sound andpractical treatment strategies for leadand copper control that are appli-cable to water systems of all sizes;determining potential adverse sideeffects on other materials andpotential users; and demonstratingthe effectiveness of differenttreatment processes.

To control corrosion in smallsystems using minimally acidicwater, ORD sponsored research toderive and test a model for limestonecontactor design, examine therelationship between contactor-treated water quality and metalrelease from pipes, and monitor thefield performance of full-scalecontactors. Results indicated thatlimestone contactors can effectivelyreduce the tendency of water to takeup corrosion by-products fromsurfaces in piping systems.

Pilot studies are beingconducted at the Cincinnati Lab totest the effects of different majorwater chemistry variables on leadpipe and other plumbing materials.Studies will determine potentialinhibitors and mechanisms of leadand copper corrosion protection inactual pipe systems, and integratethis information into a predictivetheory of leaching control. Basicinvestigations will be conducted onthe equilibria of solubility andtransport and the effect of pH,carbonate, ortho and polyphosphate,and temperature on fundamentalchemical constants.

Other studies will focus on theextent of corrosion and remediationstrategies for a range of waterqualities and problems. Designs oftreatment systems will be developedthat require little operator attentionand that provide consistent water

TreatmentLead levels in drinking water

are managed indirectly throughcorrosion controls. Lead is nottypically found in source water, butrather at the consumer’s tap as aresult of the corrosion of theplumbing or distribution system. Iftests for corrosion by-products findunacceptably high levels of lead,immediate steps should be taken tominimize consumers’ exposure untila long-term corrosion control plan isimplemented.

ResearchTo control the input of lead

and copper into drinking water, theresearch program is determining thewater chemistry and physical factors

Corrosion hascaused severeblockage in an 8-inch water mainpipe. The reddishcoloration is rustthat has built upover time and nowacts to harborbacteria in thedistribution system.

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Rust is indicative ofcorrosion in a smalldrinking waterdistribution systembuilt in1935 that hasnot been wellmaintained.

quality and corrosion control forsmall suppliers. Additionalinvestigation will be conducted onthe mechanism and control of leadleaching from brass and solder.

Summary

When evaluating treatmentoptions and alternatives for smallsystems and private homeowners,decision-makers will have toconsider the potentially very highcost for custom designed centraltreatment and its long-termoperation and maintenance versusmaintenance and monitoring ofpackage plants or home treatmentunits. Package plants or point ofentry units may present a cost-effective solution for small systemsand individual homeowners,

eliminating many of the problemssmall systems face when attemptingto finance and operate centraltreatment facilities.

Currently, several states areenacting legislation to requirecertification of treatment units,certification of water quality forhome loans, and tougher “truth inadvertising” requirements for watertreatment units. Several states arealso making it easier to acquire fundsfor treatment technology installationand upgrades and for the creation ofwater quality districts to address theproblems of small systems and ruralhomeowners.

The President’s budget forfiscal year 1994 includes resources tohelp meet state and local needs inprotecting the nation’s drinkingwater. Close to six hundred million

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A schematic of apoint of entry unitfor disinfection byozone andultraviolet light. Theunit receives rawwater at right, whichtravels through aprefilter, ozonegenerator,ultraviolet light,contact chamber,and polishing step(optional) toproduce thefinished water(outlet at left).

dollars will be invested by EPA in aDrinking Water State RevolvingFund to provide low-interest loans tocommunities for the repair andimprovement of existing systems.

Documentation of increasingcontamination of the nation’s groundwater is abundant. Small systemsand private homeowners have beenand will continue to be the mostvulnerable and least capable ofmeeting current and future drinkingwater regulations. However, long-term cost-competitive alternativesare becoming available in terms ofpackage plants and home treatmentunits to reduce the risk of contami-nated drinking water.

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References

Campbell, S., Lykins, Jr., B.W., and Goodrich, J.A. Financing Assistance Available for Small Public WaterSystems. JAWWA, 85:6:47, June 1993.

Clifford, D. and Bilimoria, M. Project Summary: A Mobile Drinking Water Treatment Research Facility forInorganic Contaminants Removal: Design, Construction, and Operation, U.S. EPA, MERL, Cincinnati,OH, (EPA-600/S2-84-018), March 1984.

Cothern, C. R., and Rebers, P. A. Radon, Radium and Uranium in Drinking Water, Lewis Publishers, Inc.,Chelsea, Michigan, 1990.

Goodrich, J.A., Stevens, T., Walsh, C. Small Systems Meet Superfund Challenge with Point-of EntryTreatment Units. Proceedings, Hazardous Materials Control/Superfund ’91, Washington D.C., December3-5, 1991.

Goodrich, J. A., Adams, J. Q., Lykins, B.W., Jr., and Clark, R. M. Safe Drinking Water from Small Sys-tems: Treatment Options. JAWWA, 84:4-55, May 1992.

Lowry, J.D., Lowry, S.B., and Cline, J.K. Radon Removal by POE GAC Systems: Design, Performance,and Cost. U.S. EPA, RREL, Cincinnati, OH, (EPA/600/2-90/049), January 1991.

Lykins, B.W., Jr., Clark, R.M. and Goodrich, J.A. Point-of-Use/Point-of-Entry for Drinking Water Treat-ment, Lewis Publishers, CRC Press, Inc., Chelsea, MI, 1992.

Parrotta, M.J. Radioactivity in Water Treatment Wastes: A USEPA Perspective, JAWWA, April 1991.

Sorg, T. Process Selection for Small Drinkihg Water Supplies, Proceedings, 23rd Annual Public WaterSupply Engineers’ Conference, University of Illinois, April 21-23, 1981.

Symons, J. M. “Plain Talk About Drinking Water,” American Water Works Association, 1992.

U. S. Environmental Protection Agency. Manual of Treatment Techniques for Meeting the Interim PrimaryDrinking Water Regulations, ORD, MERL, Cincinnati, OH (EPA-600/8-77/005), April 1978.

U.S. Environmental Protection Agency. Nationwide Occurrence of Radon and Other Natural Radioactivityin Public Water Supplies, Office of Radiation Programs (EPA 520/5-85-008), 1985.

U.S. Environmental Protection Agency. Environmental Pollution Control Alternatives: Drinking WaterTreatment for Small Communities, ORD, CERI, Cincinnati, OH (EPA/625/5-90/025), 1990.

U.S. Environmental Protection Agency and American Water Works Association. Package Water Treat-ment Plant Operation and Field Data. Vol. 1, Draft, June 1993.

U.S. Environmental Protection Agency. The National Public Water System Supervision Program: FY 1991Compliance Report, Office of Water, March 1992.

U.S. Environmental Protection Agency. Andrew W. Breidenbach Environmental Research Center SmallSystems Resource Directory (EPA/600/R-92/098), ORD, Cincinnati, OH, March 1992.

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Copies of this and other ORD publications are available from EPA’s Center for EnvironmentalResearch Information (CERI). Once the CERI inventory is exhausted, clients will be directedto the National Technical Information Service where documents may be purchased.

Center for Environmental Research InformationU.S. Environmental Protection Agency26 W. Martin Luther King DriveCincinnati, OH 45268Phone: (513) 569-7562 FAX: (513) 569-7566

Federal Funding Programs for Small Public Water Systems

Appalachian Regional Commission (202) 673-7874Dept. of Housing and Urban Development (202) 708-2690

Community Development Block GrantsEconomic Development Administration (202) 482-5113Indian Health Service (301) 443-1083Rural Development Administration (202) 720-9589

(formerly Farmer’s Home Administration)

Technical and Administrative Support for Small Public Water Systems

American Water Works Association (800) 366-0107National Rural Water Association (405) 252-0629Rural Community Assistance Program (703) 771-8636Rural Electrification Administration (202) 720-9540

(private; provides some financial funding)Rural Information Center (800) 633-7701National Drinking Water Clearinghouse (800) 624-8301USEPA, A. W. Breidenbach Environmental Research Center,

Risk Reduction Engineering Laboratory, Robert M. Clark (513) 569-7201

Sources of Information

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The research described in this report was funded by the U.S.Environmental Protection Agency and conducted as part ofthe Office of Research and Development’s comprehensive

long-term Research Issue Plan for Drinking Water.

This publication was prepared by Carol Grove of ORD’s Center for Environmental ResearchInformation (CERI), Cincinnati, Ohio, under the Office of Science, Planning and RegulatoryEvaluation. It was prepared from information developed by Jim Goodrich and staff of the DrinkingWater Research Division, Risk Reduction Engineering Laboratory (RREL), Cincinnati. Othercontributors and reviewers include Robert Clark, Tom Sorg, Ben Lykins, Walter Feige, Kim Fox,and Sue Campbell, RREL - Cincinnati; Rita Shoeny, Environmental Criteria and AssessmentOffice - Cincinnati; Ronnie Levin, Office of Science, Planning and Regulatory Evaluation; andPeter Shanaghan, Office of Water.

Thanks to Jim Goodrich, Sue Campbell, and Ed Geldreich of RREL and Jim Walasek, Office ofWater, Technical Support Division, for photographic support and to Steve Wilson, CERI, forgraphics support.

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