Preface

This document has been written as a publicservice to provide information on home drinkingwater treatment units.

The U.S. General Accounting Office (GAO)published a report in December 1991 entitledDrinking Water - Inadequate Regulation of HomeTreatment Units Leaves Consumers at Risk. Thisreport states that while many responsiblecompanies manufacture home drinking watertreatment units, federal and state prosecutors, theBetter Business Bureau and the EnvironmentalProtection Agency (EPA) have found that othercompanies selling the units make fraudulent claimsto consumers. As a consequence, consumerssometimes purchase units that are ineffective orinappropriate for their intended use. While the fullextent of consumer problems and potential healthrisks associated with the sale and use of these unitsis unknown, data GAO gathered from numeroussources indicate that dishonest marketers use avariety of misleading sales practices, andineffective units may pose a health risk toconsumers if used to treat contaminated water.

Public water systems are required toperiodically monitor to insure that safe drinkingwater is provided at all times. However, it is up tothe individual home owner to insure that privatedomestic water supplies are safe to drink. Allprivate supplies should be tested, at least on anannual basis, to insure that biologically-safedrinking water is being provided. Private suppliesshould also be tested before deciding if a homedrinking water treatment device is necessary orwhat type is the most suitable.

Where the source is not of adequate quality,home drinking water treatment devices can be usedto provide water of adequate quality that is safe todrink. The treatment options vary in bothcomplexity and price. The less informed you areabout the quality of your water, the more likely youare to purchase unnecessary, costly orinappropriate equipment.

The information provided in this documentdoes not constitute that the Department ofEnvironmental Protection (DEP) is promoting orencouraging the use of these devices norrecommending one unit or manufacturer overanother. This information is solely intended toallow consumers to make informed decisions.Further assistance is available from DEP regionaloffices and additional organizations listed in theback of this document.

Table of ContentsPage

General Information About Home Drinking Water Treatment Devices............................................................ 1

What Health-Related Contaminants Should I be Aware of? .............................................................................. 4Microbiological Contamination ....................................................................................................................... 4Total Coliform Bacteria................................................................................................................................... 4Giardia and Cryptosporidium ......................................................................................................................... 4Nitrate............................................................................................................................................................. 4Radon ............................................................................................................................................................. 5Lead................................................................................................................................................................ 5Synthetic Organic Chemicals (SOCs) .............................................................................................................. 6Pesticides ........................................................................................................................................................ 6Volatile Synthetic Organic Chemicals (VOCs) ................................................................................................ 7

What Contaminants Can Cause Aesthetic Problems? ........................................................................................ 8Iron ................................................................................................................................................................. 8Manganese ...................................................................................................................................................... 8Sulfate............................................................................................................................................................. 8Organic Material............................................................................................................................................. 8Hydrogen Sulfide ............................................................................................................................................ 8Hardness ......................................................................................................................................................... 9Chlorine.......................................................................................................................................................... 9

What Agencies Approve Home Drinking Water Treatment Devices? ............................................................. 10

What Should I Know About Companies Selling Home Drinking WaterTreatment Units? ............................................................................................................................................... 11

Installation and Maintenance of Home Drinking Water Treatment Devices................................................... 12

List of Devices for Treating Some of the More Common Contaminants andUndesirable Minerals......................................................................................................................................... 15

Types of Home Drinking Water Treatment Devices......................................................................................... 16Ultraviolet Light Disinfection Systems .......................................................................................................... 16Ion Exchange ................................................................................................................................................ 17Mechanical Filters......................................................................................................................................... 19Activated Carbon Filters................................................................................................................................ 20Activated Alumina Filters ............................................................................................................................. 21Reverse Osmosis ........................................................................................................................................... 22Distillation .................................................................................................................................................... 24Aeration ........................................................................................................................................................ 25Chlorination.................................................................................................................................................. 26

Summary of Advantages, Disadvantages and Costs of Various Types of POE/POUTreatment Devices.............................................................................................................................................. 27

Appendix A - List of Organizations Providing Information and Assistance to Consumers onHome Drinking Water Treatment Devices................................................................................ 29

Appendix B - DEP Regional Offices and Counties Served................................................................................ 31

Appendix C - Pennsylvania Maximum Contaminant Levels............................................................................. 32

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General Information About Home Drinking WaterTreatment Devices

What are home drinking water treatment devices?

Home drinking water treatment devices are usedby a home owner to improve the quality of waterentering the home. Home treatment devices arecategorized as either point-of-entry devices, whichtreat all the water entering the home, or point-of-usedevices, which treat only the water at a single tap.Common types of entry-devices or use-devices are

water softeners which remove hardness from the water,particulate filters for turbidity removal and activatedcarbon filters for removal of taste and odor problems.It is not always necessary to treat water for householdwashing and sanitary purposes to the same degree aswater used for drinking and cooking.

How do I know if I need a drinking water treatment device?

Problems that consumers are concerned with indrinking water can be described as aesthetic problemsaffecting taste, color and odor, but not necessarilyharmful, and health/safety problems which manytimes are not apparent unless the water is tested. Mostcomplaints about drinking water concern aestheticproblems, particularly taste, odor and hardness. Publicwater systems are required to maintain safe drinkingwater that does not exceed the maximum contaminantlevels for primary contaminants listed in the appendixof this document.

As public water suppliers in Pennsylvania mustmeet stringent requirements for physical, chemical andbiological contaminants, there is normally less need tobe concerned about the quality of public water thanthere is for private wells. Consumers that havequestions about their public water supply should firstcontact their local water company. The water suppliershould be able to provide you with information on thequality of the water. Home treatment devices are notrequired for health or safety problems with watersupplied from a public water system, unless public

notification indicates that a maximum contaminantlevel is being exceeded.

Deciding whether or not a home treatment deviceis needed for aesthetic improvements is fairly simplesince aesthetic problems are easily detected by thesenses. Unfortunately, deciding whether or not a hometreatment device is needed to improve the safety of thewater is not as easy. Harmful contaminants, if presentat all, may only be present in small concentrationswhich cannot be readily detected by taste and smell.Therefore, where a health/safety problem is suspected,it is essential that the water be analyzed by alaboratory to determine what contaminants, if any, arepresent and the concentrations of any contaminants.Buying a water treatment device without water testingcan be a costly mistake.

The use of department-permitted bottled water isan option to consider before purchasing a homedrinking water treatment device. The consumer shouldcompare the cost and convenience of bottled waterversus the purchasing of a home drinking watertreatment device.

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How do I select a laboratory for the water testing?

A DEP-certified laboratory should be used for drinkingwater testing. A list of such laboratories can beobtained by calling any DEP regional office (seeAppendix B or through their website athttp://www.dep.state.pa.us). A second analysis from adifferent laboratory taking a sample at a different timeis also a good idea because there is a certain margin oferror in water testing and contaminant problems mayvary.

Talk to several laboratories and discuss yourconcerns with them so they have an idea of what testsshould be done on your water. The laboratory willprovide sample containers along with instructions fordrawing your own tap-water samples. Make sure youfollow the laboratory's instructions exactly. Propersample collection is extremely important. Otherwise,the results may not be representative of the quality ofyour drinking water.

By far, the most common health threat in privatewells is from microbiological contamination, includingbacteria, viruses and pathogenic protozoans, whichcause intestinal problems.

Identifying chemical contaminants can be verycomplicated and expensive. To test for all possiblecontaminants that could be found in a well supply istoo expensive for most home owners. If chemicalcontamination is suspected, then taste, odor and theproximity to present or previous sources of pollutionnear the home (e.g., septic tanks, agriculture runoff,landfills, underground storage tanks and industrialplants) should be considered when determining whatcontaminants should be tested for. The more commoncontaminants found in groundwater are describedbelow.

How do I interpret my lab report?

Laboratory analysis results may be reported indifferent ways. The following are frequently usedterms. When referring to water, parts per million(ppm) is approximately equivalent to milligrams perliter (mg/L). One mg/L is approximately equal to ateaspoon of a contaminant in 1300 gallons of water.

1.0 mg/L = 1 ppm

It also is common to refer to contaminant con-centrations that occur at very low levels in parts perbillion (ppb). Parts per billion is approximatelyequivalent to and commonly reported as microgramsper liter (µg/L). One µg/L is approximately equal to ateaspoon of a contaminant in 1.3 million gallons ofwater.

1.0 µg/L = 1 ppb1000 µg/L = 1.0 mg/L

An easy way to convert from one to another is tomove the decimal point three places to the right whenconverting from mg/L to µg/L or three places to theleft when converting from µg/L to mg/L.

Depending on the laboratory analysis method andreporting format used, the lab report may say nonedetected (N.D.) or indicate that it was less than acertain value (e.g., <0.005 mg/L). A contaminantconcentration reported as less than a certain valueindicates that the contaminant was not detected at theminimum value the laboratory method can reliablymeasure. Some laboratory result sheets will indicate ifthe contaminant exceeds the maximum contaminantlevel.

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Maximum Contaminant Levels

Maximum contaminant levels are the maximumpermissible level of a contaminant in the waterdelivered to a user of a public water system. Themaximum contaminant levels are divided into twocategories: primary and secondary.

The primary maximum contaminant levelsregulate contaminants which may adversely affectpublic health such as arsenic, lead, radionuclides,volatile synthetic organic chemicals (VOCs), certainbacteria and pesticides. The secondary maximum

contaminant levels regulate contaminants which mayadversely affect the aesthetic quality of water, such astaste, smell, color and appearance. Public watersystems are required to periodically monitor forprimary maximum contaminant levels. Periodicmonitoring for secondary maximum contaminant levelsis not required because violations of these standardsare generally noticeable to consumers who detectchanges in color, taste and odor. Appendix C lists thecurrent maximum contaminant levels.

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What Health-Related Contaminants

Should I Be Aware of?Health-related (primary drinking water) contami-

nants that consumers should be aware of are micro-biological contamination, total coliform bacteria,Giardia lamblia and Cryptosporidium parvumprotozoa, nitrate, radon, lead, synthetic organicchemicals (SOCs), VOCs and pesticides.

Microbiological Contamination. Microbiologi-cal contamination is normally a problem with privatedomestic wells which do not receive the disinfectionthat a public drinking water source does. The sourceof microbiological contamination in groundwater canbe from on-lot sewage (septic) systems or agriculturalrunoff. Improper well construction and poor locationof the well can result in microbiological contamination.The presence of coliform bacteria in drinking water iseasy for a certified laboratory to detect and can beused to assess the likelihood that other microbiologicalcontaminants are present. Test kits for collecting totalcoliform bacteria samples are available from eitherDEP-certified private laboratories or the DEP regionaloffices listed in Appendix B. Individuals should havetheir well water tested for bacteria at least annually.

Total Coliform Bacteria. The total coliformbacteria test is used to determine if bacterial contami-nation is present. Although most coliform bacteria donot cause illness, the total coliform test is easy andinexpensive, and is used as an indicator for the possi-ble presence of other disease-causing microorganismsin the water. If coliform bacteria are in your water,then bacteria and viruses that can make you sick mayalso be contaminating your supply. The acceptablelevel is for no coliform bacteria to be present.However, a test report for an uncontaminated samplemay read coliform negative, less than one (<1) per100 mL, or less than 2.2 (<2.2) per 100 mL,depending on the measurement and reporting techniqueused by the individual laboratory. Ultraviolet disinfec-tion treatment devices can provide water that is safefrom microbiological contamination. Chlorination isalso an effective means of disinfection, and is normally

used when problems such as high iron or hydrogensulfide also are present.

Giardia and Cryptosporidium. Giardiasis is awaterborne disease caused by the protozoan Giardialamblia that lives in the small intestine of warm-blooded mammals. Similarly, cryptosporidiosis iscaused by Cryptosporidium parvum. Infection resultsfrom drinking water from a surface or surface waterinfluenced source contaminated by Giardia cysts.Giardia normally is not a problem with groundwatersources, unless they are under the direct influence ofsurface water. Public water systems that test positivefor Giardia cysts are required to immediately notifyconsumers of the problem. Additional information onGiardia can be found in a pamphlet entitled Crypto-sporidium & Giardia...Are They in Your DrinkingWater? available from the DEP regional offices listedin Appendix B or through the website athttp://www.dep.state.pa.us (choose directLINK“Drinking Water Publications”). Mechanical filtrationis the most cost-effective way to remove Giardia cysts,although reverse osmosis and distillation also willwork. It is recommended that consumers purchase adevice that is in the NSF International Listings forGiardia cyst removal.

Nitrate. Nitrate is a fairly common drinkingwater contaminant, usually associated with wells andsprings in agricultural areas. Public water suppliesroutinely must test for nitrate and remove it if it ex-ceeds drinking water limits, but many private wellsmay contain high levels of nitrate without the ownersbeing aware of it. High nitrate levels usually resultfrom agricultural activities or on-lot sewage systems.Chemical fertilizers and manure are rich sources ofnitrogen compounds, which are converted to nitrate inthe soil. People, particularly those with youngchildren, living in farming areas who obtain their waterfrom individual wells, springs or surface sourcesshould have their water tested regularly for nitrate.

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At high concentrations, nitrate can cause methe-moglobinemia, commonly called blue baby syndrome,in infants. Infants less than three months old are atgreatest risk from the illness, which deprives vitalorgans of oxygen. This disease, although uncommon,can occur when high concentrations of nitrate are inthe drinking water. For public drinking water sup-plies, the maximum contaminant level for nitrate is 10mg/L expressed as nitrogen (N) or 45.0 mg/L ex-pressed as nitrate (NO

3). Nitrate levels can change

drastically based on rainfall, fertilizer application andgeology. The test for nitrate is relatively inexpensive,typically $15 to $20.

Reverse osmosis, ion exchange and distillationtreatment devices are effective for removal of nitrates.

Radon. Radon is a naturally occurring radio-active gas that is found in varying concentrations inmost soils and rock. Radon gas can cause lung cancer.Normally, most radon that accumulates in the homeseeps from the soil into the home through cracks andholes in the foundation. However, in some cases,household water can be the primary or a contributingsource. In these cases, radon is emitted into the homefrom water used for showering, cooking and washing.It is only a problem where groundwater is used tosupply drinking water. The danger primarily is fromthe inhalation of radioactive gas given off, rather thanconsumption of the water.

To find out if you have a problem with radon inyour home, have the air tested first. If the air level isless than 4 picocuries per liter (pCi/L), there usually isno need to have the water tested. If the air level innon-basement areas is above 4 pCi/L, then the watershould be tested to determine if it is the primary or amajor contributing source. A level of 10,000 pCi/L, inthe water will increase indoor air levels by about 1pCi/L.

Since radon levels in the air can vary substanti-ally from day to day, it is a good idea to have at leasttwo air samples taken with the samples spaced overseveral days in a closed house. Air sampling can bedone with a home test kit costing $20 to $50. Long-term tests, which are a better indicator, can also beused, particularly where initial test results indicatehigh levels. Having a water sample analyzed by alaboratory for radon will cost from $20 to $35.

If radon levels in the water are excessive, venti-lating the kitchen, laundry and bathrooms may reducethe radon concentrations in the home to an acceptablelevel. If additional tests show excessive levels, sometype of water treatment should be considered. Twotypes of devices that work very well in removing radonare activated carbon and aeration treatment devices.Entry-device treatment devices should be used whereradon is a problem. Because radon decays rapidly,radioactivity will not build up in the treatment devices,unless radon concentrations are exceptionally high inthe raw water. If radon levels are high, lead-210, aradon decay product can build up in the carbon filterand give off harmful radioactivity. Where high radonconcentrations are measured, it is advisable to shieldthe unit, or place the unit outside the home or in anisolated area of the basement.

To get more information on radon in the home, callDEP's Radon Hotline at 1-800-237-2366 or write:

DEPBureau of Radiation Protection

P.O. Box 8469Harrisburg, PA 17105-8469

or visit their website at http://www.dep.state.pa.us

An information packet will be sent to you whichincludes information on radon testing methods, theradon concentrations at which action should beundertaken, methods of reducing radon levels in thehome and a list of certified mitigation companies.

Lead. Lead from pipes and solder can dissolveinto drinking water as the water flows throughplumbing systems. In most cases, lead in drinking wa-ter comes from the household plumbing, not from thewater source or the public water system. The highestlead concentrations are found in homes with leadservice lines or lead plumbing. Lead commonly wasused for service lines, the line connecting the home tothe water main, in homes built up to the early 1950s.Most public water suppliers maintain records of whattype of pipe was used for service lines.

High lead concentrations also can be found inhomes with copper piping where lead solder was usedfor joining pipes. Copper is the most popular type ofresidential piping and is found in most homes. High

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lead concentrations can be found in newer homeswhere lead solder was used.

In July 1989, Pennsylvania passed the PlumbingSystem Lead Ban and Notification Act. ThePennsylvania "Lead Ban" prohibited the use of leadsolder and lead pipe, on a statewide basis, after Jan. 6,1991. Local building codes in some municipalitieshave prohibited the use of lead solder and lead pipe forseveral years.

Brass and bronze in faucets and other plumbingfixtures often contain lead and may be a considerablesource of lead in the drinking water of homes withbrass or bronze faucets or fixtures.

Drinking water is only one possible source oflead to the human body. Other sources include paintchips, air, soil, food and dust. Infants, young childrenand pregnant women are at greatest risk from leadexposure. The effects of lead on children include in-creased hyperactivity, decreased intelligence levels,learning deficiencies and kidney disorders.

Since you cannot see, taste, or smell lead, theonly way to tell if you have a lead problem in yourdrinking water is by having your water tested. In lightof new health and exposure data, EPA has reduced thelead standard for drinking water to 0.015 mg/L. Iftests show that the level in household water is in thearea of 0.015 mg/L or higher, it is advisable,especially if there are pregnant women or youngchildren in the home, to consider treatment to reducethe lead level in your tap water, use permitted bottledwater, or use a flushing program to reduce the leadlevels in the water that is consumed.

As water sits in the household plumbing orservice line, lead can be leached from old lead pipes,lead soldered joints, or brass or bronze plumbingfixtures. Water that has a lower alkalinity or pH ismore corrosive and will leach more lead into the water.The longer the water lays unused in the pipes, thegreater the potential for increased amounts of lead inthe water. In homes where plumbing work recentlyhas been done, home owners should check the screen inthe faucet aerator and remove any loose particles ofsolder. Lead concentrations can be reduced byallowing the water to run at the faucet after periods ofnonuse. Anytime the water in a particular faucet has

not been used for six hours or longer, the water shouldbe run until a noticeable change in temperature can befelt. The flushing will clear out the water which hasbeen sitting dormant in the pipes and should substanti-ally reduce the lead concentration in the water wherethe plumbing system is the source of thecontamination. After flushing, water can be stored forlater use for drinking and cooking.

The other way to reduce lead concentrations is touse point-of-use treatment devices. Several types oftreatment devices can work quite well to remove leadincluding reverse osmosis, activated alumina, someactivated carbon absorption filters with designs suchas precoat or carbon block, and distillation. If yourdrinking water exceeds the drinking water action levelfor lead of 0.015 mg/L, purchasing a device that is inthe NSF International Listings will insure that thedevice has been tested and is effective for leadremoval. Be sure to maintain the system asrecommended by the manufacturer. If lead is the onlycontaminant, an activated alumina filter can be used toreduce lead concentrations. If lead is only one ofseveral contaminants, then an activated carbon filtervalidated as effective for lead reduction by NSFInternational Listings or a more expensive reverseosmosis system, both of which can remove a greaternumber of contaminants, may be needed.

To get more information on lead in the home, in-cluding a copy of The Pennsylvania Lead Ban andYou, contact your DEP regional office. Lead inDrinking Water in Schools and NonresidentialBuildings is available by contacting EPA DrinkingWater Hotline, at 1-800-426-4791 or visit theirwebsite at http://www.epa.gov/safewater.

Synthetic Organic Chemicals (SOCs). Theterm synthetic organic chemicals refers to all man-made organic chemicals, of which thousands areknown to exist.

There are many SOCs, and their applicationsvary from such uses as heat exchangers (poly-chlorinated biphenyls or PCBs) to fuel oils (kerosene).Common synthetic organic chemicals include dioxin,lindane, chlordane and endrin.

Technically, both pesticides and volatile organicchemicals are all SOCs. Due to their unique

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characteristics, pesticides and volatile organicchemicals typically are placed in separate categories.

Pesticides. Pesticides are a broad class of com-pounds that include herbicides, insecticides androdenticides. Pesticides can enter a drinking watersupply from direct application for the control of vege-tation or insects and from non-point sources such asrunoff from agricultural, urban and suburban areas.The majority of health effects data that has beenaccumulated has been based upon exposure to rela-tively high concentrations resulting from sprayingoperations or industrial accidents. Activated carbonfilters are effective for the removal of pesticides.

If you believe that pesticides may have contami-nated your drinking water, several sources can provideyou with additional information. These sources in-clude DEP regional offices, the Pennsylvania Depart-ment of Agriculture, the Penn State CooperativeExtension and the National Pesticide Telecommunica-tions Network listed in Appendix A. Laboratories alsocan be of assistance in determining what to test for ifyou are unsure of what pesticides may have been used.

Volatile Synthetic Organic Chemicals (VOCs).Volatile synthetic organic chemicals are man-madesubstances that have been responsible for the contami-nation of both surface and groundwater supplies.VOCs have a wide variety of uses in many types ofindustrial, commercial, agricultural and householdactivities. VOCs may also form from the naturalbreakdown of SOCs in the environment.

Public water suppliers must meet stringent re-quirements for VOCs. However, some private wells orsprings may contain VOC levels that are cause forconcern. You are far less likely to find VOCs in your

water than bacteria or nitrate. VOC contamination hasbeen found near petroleum refineries, chemical plants,manufacturing plants, landfills, leaking undergroundstorage tanks and as the result of careless storage ordisposal around the home. If you live near one of thesetypes of facilities or are concerned about possiblecontamination, you should have your water tested forVOCs. Many VOCs will not be detectable by the tasteor odor of the water.

VOCs can be removed from water by boiling thewater in a well ventilated area for 10 to 15 minutes, byaeration treatment devices, or by filtering the waterthrough activated carbon treatment units.

Chlorination of water that is high in naturallyoccurring organic compounds can produce smallamounts of trihalomethanes or THMs (chloroform,bromodichloromethane, dibromochloromethane andbromoform). The drinking water standard that publicwater systems are required to maintain for total tri-halomethanes is 0.08 mg/L (80 ppb). Long-termexposure to levels above this standard may contributeto a small additional cancer risk. Despite these risks,however, the disease prevention benefits of chlorina-tion still outweigh the small negative effects oftrihalomethanes. Activated carbon filters arecommonly used to reduce SOCs.

More information on VOCs can be obtained fromDEP's Citizen's Guide to Volatile Synthetic OrganicChemicals in Drinking Water, which is available fromDEP regional offices or through the website athttp://www.dep.state.pa.us (choose directLINK“Drinking Water Publications”).

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What Contaminants Can Cause Aesthetic Problems?Secondary drinking water contaminants are

regulated to prevent taste, odor, color and otheraesthetic drinking water quality problems. Thesecontaminants include iron, manganese, sulfate, organicmaterial, hydrogen sulfide and hardness.

Iron. Iron can be a major nuisance in a privatewater supply. It stains laundry and fixtures, promotesthe growth of iron bacteria slimes in plumbing andgives water a bitter, metallic taste. Iron can be presentin the water in two forms— soluble and oxidized. Aseach form can require a different type of treatmentdevice, you need to determine which form is present inyour water so that the proper treatment device can beselected. Trained personnel in the water treatmentfield can help you with this. The secondary drinkingwater standard for total iron is 0.3 mg/L.

Soluble iron, also called clear water iron orreduced iron, is easily recognized because the water isclear when first drawn, but soon becomes filled withred rust if left standing. Soluble iron causes reddish-brown stains on plumbing fixtures, porcelain, cookingutensils and laundry.

Soluble iron, usually up to 3.0 mg/L, can beremoved by an ion exchange treatment device. Amanganese greensand oxidizing filter will be effectivefor concentrations up to 10.0 mg/L. For concentra-tions above 10.0 mg/L, chlorination followed by filtra-tion is usually needed.

Oxidized iron, frequently referred to as red wateriron, is formed when water containing soluble ironreacts with air. The iron found in surface water isusually oxidized. Water containing oxidized iron willshow rust particles or black specks suspended in thewater. Red water iron, like clear water iron, causesreddish-brown stains on clothes, porcelain and cookingutensils. Oxidized iron can be removed by mechanicalfiltration or chlorination.

Small particles of oxidized iron that do not settleout are referred to as colloidal iron. These smallparticles cannot be removed by ordinary filtration.Colloidal iron, like other forms of iron, causes reddish-brown stains on laundry, plumbing fixtures and

cooking utensils. Colloidal iron may be found in waterfrom shallow wells, but is seldom found in deep wellsupplies. The presence of colloidal iron can be shownby the use of filter paper. In some cases, the additionof alkalinity to the water may allow the colloidalparticles to agglomerate into settleable, filterableparticles that can be removed by mechanical filtration.Colloidal iron can be removed by chlorination.

Manganese. Manganese causes dark brown toblack stains on plumbing fixtures and will causelaundry to be stained black. Manganese can cause anunpleasant taste and appearance in coffee, tea andother beverages. Manganese can be removed with awater softener. The secondary drinking water standardfor manganese is 0.05 mg/L.

Sulfate. Water containing high concentrations ofsulfates will have a laxative effect and a bitter taste.The secondary drinking water standard for sulfates is250 mg/L. Sulfates can be removed by ion exchangeand reverse osmosis.

Organic Material. One source of color in wateris from small amounts of organic material from the de-composition of fallen leaves, algae and other plantmatter. This decaying vegetation produces humicacids also referred to as tannins. The color in thewater may not be visible in a glass of water but will beevident when viewed against a white background in asink or bath tub. These materials are found in surfacewater and are normally harmless. Phenols producedby this organic decomposition may result inobjectionable taste and odor even when present insmall amounts. Activated carbon filters can removemost organic material.

Hydrogen Sulfide. Hydrogen sulfide is a gasproduced by the decomposition of underground organicdeposits. It readily dissolves in water and gives it acharacteristic rotten egg odor and obnoxious taste.Hydrogen sulfide is very corrosive and will rapidlytarnish silver causing it to turn black. In some cases,hydrogen sulfide may be present in the hot water, butnot the cold. In this situation, a chemical reaction isoccurring in the water heater between the magnesium

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anode of the water heater and sulfate in the water.Removal of the magnesium anode will usuallyeliminate the problem. Treatment to reduce hydrogensulfide includes manganese greensand filtration orchlorination followed by filtration and aeration.

Hardness. Hardness is caused by dissolvedminerals, primarily calcium and magnesium, which arepicked up by water as it travels through rocks andsoils. Hardness is a common problem where groundwater is used as a water supply. The highest concen-trations of these minerals come from wells in limestonerock. High concentrations can result in mineraldeposits in water heaters and pipes, and film on sinksand bathtubs. Hardness also requires increased soapusage in dishwashers and washing machines. A majorproblem caused by hardness is reduced efficiency ofwater heaters resulting in premature replacement. Thefollowing table shows a rating system commonly usedto describe the hardness of water.

Lab results frequently will refer to minerals inwater as grains per gallon (gpg). One grain per gallonof calcium for example is equal to 17.12 mg/L as

CaCO3. Thus multiply grains per gallon by 17.12 toobtain the equivalent value in milligrams per liter.

Hardness usually is treated using ion exchangewater softeners. The level of hardness at whichtreatment is used to soften the water varies, dependingon consumer preference. Reducing the hardness of thewater too much may make the water corrosive to theplumbing system and can in some instances result inincreased lead concentrations.

Chlorine. Chlorine is used to kill and preventthe regrowth of harmful microorganisms in watersupply systems. However, high levels of chlorine canresult in taste and odor problems. Chlorine also cancombine with other drinking water contaminants toform chloramines, which can create noticeable tasteand odor problems.

Activated carbon filters are effective inremoving taste and odor problems associated withchlorine.

Hard Water LevelsGrains Parts Per Million

Per Gallon (mg/L as CaCO3) Ratingless than 1.0 less than 17.1 soft

1.0 - 3.5 17.1 - 60 slightly hard

3.5 - 7.0 60 - 120 moderately hard

7.0 - 10.5 120 - 180 hard

over 10.5 over 180 very hard

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What Agencies Approve Home Drinking Water Devices?

Neither EPA nor DEP tests, certifies or endorseshome drinking water treatment devices. Occasionally,you may come across a device with a label saying"Registered With EPA.'' This registration is requiredfor devices, usually carbon filters, that contain achemical treatment of the filter, typically impregnatedsilver that inhibits the growth of bacteria on the filtermaterial. Registration does not necessarily mean thatthe device works effectively or that it kills harmfulbacteria. EPA registration only ensures that the filterwill not leach unacceptable levels of the silverbactericide into the drinking water. Recent studieshave shown that the impregnated silver has little effecton killing harmful bacteria and other microbiologicalcontaminants.

One nonprofit organization that tests and certifiestreatment devices is NSF International. NSFInternational is a private, independent, non-profitorganization that develops and maintains standards fordevices and equipment related to public health. NSFInternational has certification programs for testing andapproving treatment devices for the removal of specificcontaminants. Use-/entry-devices certified and listedby NSF International will have the NSF Internationalmark printed on the device.

If your water is contaminated with health-relatedcontaminants such as cysts or excessive lead levels,look for devices certified under ANSI/NSF Standard53 for those particular contaminants. The following isa list of standards under which NSF International testsand certifies home drinking water treatment devices.

Standard Title

ANSI/NSF 42 Drinking Water Treatment Units --Aesthetic Effects

ANSI/NSF 44 Cation Exchange Water Softeners

ANSI/NSF 53 Drinking Water Treatment Units--Health Effects

ANSI/NSF 55 Ultraviolet Microbiological WaterTreatment Systems

ANSI/NSF 58 Reverse Osmosis Drinking WaterTreatment Systems

ANSI/NSF 62 Drinking Water Distillation Systems

Certification indicates that the product has metperformance standards for removing a test concentra-tion of a particular contaminant. Devices that are cer-tified under ANSI/NSF Standard 53 for Health Effectswill indicate if the device has been approved for cystreduction, lead reduction, VOC reduction, turbidityreduction, etc.

A listing of home treatment devices meeting NSFStandards can be obtained by contacting:

NSF International789 Dixboro Rd.Ann Arbor, MI 48105Telephone: 800-NSF-MARK

734-769-8010or visit their website at http://www.nsf.org

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What Should I Know About Companies Selling HomeDrinking Water Treatment Units?

There are many responsible businesses andcompanies in the home water treatment business thatoffer products that live up to their claims. However,some companies and salespersons resort to gimmicksand false claims about the safety of drinking water,including water provided by public water systems, inorder to sell their products. In some cases consumers

have purchased products that are unnecessary, costlyor provide treatment in excess of what is required.The less informed you are about the quality of yourwater, the more likely you are to purchaseunnecessary, costly or inappropriate equipment.

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Installation and Maintenance of Home Drinking WaterTreatment Devices

Should I provide treatment for all the water in the home or just at one tap?

The type of treatment chosen, point-of-entry forthe whole house versus point-of-use for an individualtap, will depend on the nature of the problem. Fortaste and odor problems, use-devices normally willsuffice. Minerals that cause scaling on water heaters(calcium and magnesium) or staining of laundry (ironand manganese) should be removed by entry-devices.

Entry-devices also should be used to remove ordisinfect health-related contaminants such as bacteria,organic chemicals and radon. If use-devices are usedto remove health-related contaminants, home ownersmust make sure that water is not consumed by childrenor visitors from faucets without home treatmentdevices.

How much maintenance is required with home drinking water treatment devices?

All devices require routine maintenance to remaineffective. Do not expect to install a home treatmentdevice and be able to walk away from it. In manycases maintenance is not expensive or time consuming.In most cases part of the device will have to bereplaced at least once a year including filter cartridges,reverse osmosis membranes and ultraviolet lightlamps. It is important to note that the treatment devicewas tested under conditions that probably are differentfrom those in your home, and the actual service lifemay differ from the manufacturer's rated service life.

Before purchasing a device, find out about themaintenance requirements and costs from the dealer.Filters that are manufactured without a replaceablefilter element are usually more costly to operate, as theentire unit is replaced each time. If you purchase adevice, have it maintained according to themanufacturer's instructions. An improperlymaintained device could cause more harm than good.Keeping accurate maintenance records on treatmentdevices is very important.

Can home drinking water treatment devices reduce drinking water quality?

Yes, bacteria can grow in some devices,particularly activated carbon units. These bacteria arenormally harmless. In other cases contaminants thathave been removed by a filter could overload the filter

and eventually wash out into the drinking water if thefilter is not replaced. In order to avoid these problems,the devices must be used and maintained properly.

Some items to keep in mind when considering the purchase of a home drinking water treatmentdevice:

• Neither DEP nor EPA certifies or endorses thesedevices. Beware of sellers who make such claims.

• Beware of false claims about the quality andsafety of public drinking water. Despite all thepublicity about drinking water pollution, drinking

water from public water suppliers should be con-sidered safe unless your water supplier has issuedthe required public notification to the contrary.

• When deciding whether you need to purchase adevice for health-related contaminants, have the

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water tested by a DEP-certified laboratory. Use alaboratory not affiliated with the seller of hometreatment devices.

• Beware of home demonstrations that visuallyshow problems with the water, such ascloudiness or solids in the water. These areusually gimmicks designed to scare the consumerinto purchasing the treatment device immediately.Be especially cautious if anything is added tothe water to develop this effect. The substanceadded is usually a flocculating agent, which causesdissolved minerals, present in all water, to formlarger particles and settle in the bottom of thecontainer.

• Prices can vary widely, so shop around andcompare prices and features from differentsuppliers and manufacturers. Be sure that you arepurchasing the right kind of device. A salespersonmay recommend a more expensive device such asa reverse osmosis unit, when a less expensiveactivated carbon or an entry-device water softenermay be what is needed. Remember that price isnot the only consideration. Be sure that the equip-ment can solve your particular water problem.

• Look for devices certified and listed by NSFInternational that have been tested and certified asmeeting their standards.

• Ask to see the manufacturer's test information onthe percentage removal for the contaminants ofconcern and compare that with the levels in yourdrinking water. Removal efficiencies vary amongdifferent types of devices and differentmanufacturers, and in most cases are not100 percent. Do not take a sales representative'sword that the device is effective for a particularproblem or contaminant unless such claims can bedocumented.

• Check with the Better Business Bureau to find outif there are unresolved complaints against theseller. Their web address is http://www.bbb.org.

• Beware of promotional gimmicks such as prizes,gifts or free trips. If it seems too good to be true,it usually is.

• Before buying, find out about warranties, main-tenance, the cost and availability of replacementfilters and other parts and any installation costs.Also ask the dealer about other installations in thearea. Sellers or dealers should be able to providereferences allowing you to contact previouspurchasers of the treatment device in your area.

• Salespeople should provide you with a writtenestimate and allow you to consider and reviewyour options before making a decision.

Installation of point-of-use devices:

Point-of-use treatment devices can be connectedto the water system in several ways.

Countertop devices are not connected directlyto the plumbing system, but require the user to pourwater into the unit on a routine basis. Because theunits are fairly small, this type of device usually isonly capable of producing a small amount of waterduring a given time period. Other countertop devicesare designed to be temporarily connected to the faucetwith a hose. Reverse osmosis, distillation andactivated carbon units are available in countertopmodels. Little or no installation work is required forcountertop devices.

Faucet-mounted devices are permanentlyconnected to the faucet and treat all of the watercoming through the faucet. This class of device islimited to activated carbon and mechanical filters.Because of the small size and insufficient contact time,this type of device is not recommended except toprovide for taste and odor concerns.

Undersink cold tap devices are placed under thesink and are directly attached to the cold water line.Thus, all cold water going to the tap is treated.

Undersink line bypass devices, also called thirdfaucet devices, are connected to the cold water lineunderneath the sink but bypass the regular faucet.Instead, water is fed to a separate faucet that is

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installed on the sink. Water flows through a linebypass device in a slow, controlled manner allowingfor greater contact time than other types ofinstallations. For this reason, these types of devicesare the most effective. Every type of use-device

described in this guide is available in a line bypassmodel. Most line bypass point-of-use units canproduce approximately one gallon of treated water perminute.

Installation of point-of-entry devices: Because the installations are fairly complex and

improper installation can result in the units notoperating properly, entry-devices should be installedonly by experienced plumbers. In most cases, entry-devices are installed near the point where the water lineenters the home and where it is accessible formaintenance.

Depending on the type of treatment, it may bepossible to bypass some of your water around thetreatment system so that only a portion of the water istreated. For example, in some water softeningsystems, it may be possible to soften only the waterentering the water heater, leaving the cold water lineuntreated. This would reduce the cost of watertreatment and would provide softened water where it is

most needed such as dishwashers, showers andlaundries. Entry-devices used for health-relatedcontaminants should treat all the water entering thehome, although treatment is not needed for faucetsused for non-drinking or non-consumption purposessuch as lawn watering or car washing.

Entry-device systems should include a sampling tapprior to and after the units to allow the performance of theunit to be monitored. They should include a bypass valveand piping which will prevent interruption of the watersupply during backwashing, maintenance or breakdown ofthe unit. To adequately supply a typical home, entry-device systems should be capable of producing seven toten gallons of treated water per minute.

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List of Devices For Treating Some of the More CommonContaminants and Undesirable Minerals

Contaminant andMinerals

UV LightIon

Exch.Mech.Filter

Actd.Carbon

Actd.Alum

ReverseOsmosis Distillation Aeration Chlorination

Bacteria and Viruses • •Taste and Odor • • •Lead • • • • •Nitrate • • •Chlorine,

Trihalomethanes•

Radon • •Hardness •VOCs and other

Organics• •

Pesticides, PCBs • •Iron andManganese

• • •Sulfate • • •Giardia andCrytosporidium Cysts

• • •Sediment,Turbidity

•Total DissolvedSolids

• •Aluminum • •Arsenic • • •Barium • • •Cadmium • • •Chloride • •Chromium • •Copper • •Fluoride • • •Mercury • •Radium • • •Selenium • • •Silver • •Zinc • •

Treatment Device

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Types of Home Drinking Water Treatment Devices

This section describes how some of the more commontypes of home treatment units work and some of theadvantages and disadvantages of each type oftreatment device.

A list of some of the more common types of contami-nants and the types of devices used to treat eachcontaminant is listed in the table on page 15.

Ultraviolet Light Disinfection Systems

Ultraviolet (UV) light systems are used solely fordisinfection. In a typical UV system, water enters achamber containing a mercury lamp. When operatingproperly, the ultraviolet light emitted from the lampdestroys harmful bacteria and viruses. No chemicalsare added to the water so there are no added tasteproblems.

An ultraviolet system will not be effective onwater that has high turbidity (cloudy) because the lightcannot penetrate to kill all harmful microorganisms.Water with high turbidity levels should be filtered andin some cases treated by an ion exchange processbefore it passes into the ultraviolet unit. Ultravioletunits are not effective for inactivation of Giardia orCryptosporidium cysts, which should be removed by amechanical filter certified by NSF International forcyst reduction.

The intensity of the ultraviolet light emitted bythe lamp gradually decreases and eventually the unitbecomes ineffective for killing bacteria. The decreasein lamp output can be caused by a weak or burned-outlight or by sediment coating the lamp. To avoid thisproblem, units should have a means to alert the userwhen the intensity of light reaching the outsidechamber falls below a minimum acceptable level. Thebest method is a shutoff or audible alarm that soundswhen the ultraviolet lamp is not maintaining therequired intensity to ensure proper disinfection. The

sight port on most existing UV treatment devices willaccept a warning alarm. Besides the added assurancethat the water is receiving adequate treatment, theadditional cost of the alarm is offset by the longerservice life for each lamp if cleaning is all that isrequired.

The lamps inside the unit are replaced on anannual basis or when the alarm indicates that the lampoutput has decreased to a level where it is no longereffective. To be effective, the lamp must be keptclean. Devices are designed to be cleaned usingchemical solutions, usually on an annual basis whenthe UV light is replaced. Mechanical wipers are some-times included to provide additional removal of dirtfrom the UV lamp between cleanings.

To ensure the safety of all the water usedthroughout the home, entry-device systems arerecommended, although smaller use-devices are alsoavailable.

Entry-device systems should be rated for a mini-mum of 7-10 gallons per minute, with larger unitsnecessary where there is greater peak water usage dueto the size of the household or additional bathrooms.If more water is passed through the unit than the unitis rated for, the water will not be adequatelydisinfected. To prevent this from happening, a flowcontrol device should be installed with each unit.

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Ion Exchange

The most common and oldest application for ionexchange is water softening which removes hardness.In water softening, calcium and magnesium ions areexchanged for sodium or potassium ions. There aremany reliable softeners on the market.

Ion exchange treatment devices can removedifferent dissolved inorganic minerals from water, suchas calcium, magnesium, sulfates, etc. Inside an ionexchange device, water passes through a filter resin.Calcium and magnesium in the water are exchangedfor sodium or potassium. Thus one mineral is replacedby another.

Eventually, the resin becomes saturated and mustbe regenerated. This is done automatically by flushingthe material in the softening tank with the salt orpotassium brine. An automatic timer on the ionexchange unit commonly is used to regulate when thisregeneration cycle occurs. The length of time betweenregeneration cycles is set for a given period of timedepending on the hardness of the water, the amount ofresin in the tank, and your water usage. Other unitscalled demand-initiated regeneration (DIR) measurethe amount of water used since the last regeneration, ormeasure increasing hardness to determine the timing ofthe regeneration cycle. The less expensive timer-

controlled units will work well if your water usageremains relatively constant.

Persons on a strict low sodium diet shoulddiscuss with their physician the use of a softener whichuses sodium chloride, as the sodium concentration ofthe water will increase. However, the amount ofsodium consumed from water treated by a softener issmall in comparison to typical sodium amountscontained in prepared foods such as snacks, soups,cereals and prepared meats. For consumers concernedabout sodium, water softeners are available that usepotassium as the exchange ion rather than sodium.Drinking water taps also may be bypassed to providesoftened water for bathing, cleaning and laundering.The use of bottled water is another option to consider.

The exchange process used in water softening iscalled a cation exchange process. There is also ananion exchange process in which a different resin isused for nitrate, chloride and sulfate removal. If thewater is high in both sulfate and nitrate, it may benecessary to use a two-stage system that removessulfate first and nitrate second. Otherwise, the sulfatewill interfere with the performance of the unit. Anionexchange systems are the most common systemschosen for nitrate removal.

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A variety of other inorganic minerals can beremoved by ion exchange systems. These are listed inthe table on page 15.

The use of softener units not designed for ironremoval can result in coating of the resin with iron andpremature replacement of the unit. Normal ionexchange treatment devices can be used for iron andmanganese removal only when these minerals occur infairly low concentrations of less than 1 mg/L. Forhigher iron concentrations, a specialized unit utilizingan iron stripping agent in the salt or an oxidizingmanganese greensand filter will be required. A

manganese greensand filter is similar in design to otherion exchange units. The greensand resin providesoxygen to oxidize the iron, manganese or hydrogensulfide. Potassium permanganate is used to regeneratethe greensand, once it becomes depleted of oxygen.

Ion exchange devices used for lead removalshould be specifically designed by the manufacturerfor this purpose. If lead comes from the householdplumbing, lead removal devices should be use-devicesinstalled at the tap.

Ion Exchange Water Conditioner

1. Raw water flows into the mineral resin tankcontaining the resin, where calcium andmagnesium ions are exchanged for sodium ions.

2. Salt storage container, the salt brine formed hereis used to regenerate the resin in the mineralresin tank.

3. Control valves and timer used for control whenregeneration takes place.

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Mechanical Filters

Filters are the simplest of home drinking watertreatment devices. They trap particles in a porousmaterial while allowing water to pass through thematerial. Filters can be made of sand, fibers,anthracite, ceramics or other man-made materials.Filters can remove particles such as rust and sediment.Some filters are also effective for turbidity (cloudywater) and Giardia or Cryptosporidium cyst removal.Due to the potential health effects of ingesting cysts,mechanical filtration units purchased for cyst removalshould have the NSF International mark and be in theNSF International listings indicating that they havebeen tested as being effective for cyst reduction.Mechanical filters cannot remove dissolvedconstituents in the water. For this reason, they areineffective at removing many common contaminantssuch as hardness, salt, nitrate, organic chemicals andmost metals. Mechanical filters are commonly used aspretreatment for reverse osmosis, ultravioletdisinfection and other treatment processes.

As filters remove particles from the water, theyget clogged and have to be replaced or cleaned. Themore solids in the water, the faster the filter will clog.

The need for maintenance will be signaled by adecrease in flow through the filter. Dirty filters cancause an increase in bacteria in the water.

Oxidizing filters (e.g., manganese greensand) area particular type of filter used for iron, manganese andhydrogen sulfide removal. These filters use anoxidizing chemical that converts minerals to an insolu-ble form which is more easily removed by filtration.Oxidizing filters usually require some type ofcontinuous chemical addition— normally chlorine orpotassium permanganate.

Mechanical filters can be used for either point-of-entry or point-of-use treatment. For entry-devices, thefilter material is normally cleaned by automaticbackwashing. For use-devices, it is typically moreeconomical to simply replace the filter cartridge anddispose of the spent cartridge. Some filters utilize astandard filter size that is available from manydifferent manufacturers, while others require a filterthat can only be purchased from that particularmanufacturer. In both permanent and disposable filtertypes, backwashing or cartridge replacement must bedone on a routine basis.

Mechanical Filter1. Water enters top of the filter and passes alongside

and into the filter material.

2. Contaminants are trapped in the filter while waterpasses through.

3. Filtered water leaves the unit.

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Activated Carbon Filters

Activated carbon filters use carbon material (e.g.,coal, charcoal, wood or bone) to absorb dissolvedorganic material, radon and chlorine from water. Thecarbon contains a vast network of minuscule channelsand a large surface area on which contaminants areabsorbed as the water passes through the charcoal.

Activated carbon will remove chlorine,trihalomethanes, radon, pesticides and most organiccompounds. However, it will not remove mostinorganic compounds, such as nitrate, and is not meantto remove particulate matter, such as suspended solids.Activated carbon filters are often used to improve theaesthetic quality of water since they are very effectiveat reducing taste, odor and color problems. Thepresence of solids in the raw water will shorten theexpected life of the filter by clogging it. Certain typesof carbon filters, such as some carbon block filters, areeffective for lead removal. Carbon block filters havethe carbon pressed into a solid block and are able tofilter small particles.

Normally, the price for an activated carbon unitis less than other types of treatment devices. Unlikesome of the other treatment processes, activatedcarbon does not require electric power and does notwaste water.

Activated carbon is used in both point-of-entryand point-of-use treatment devices and is installed invarious fashions including faucet mount, pourthrough countertop and separate faucet line bypassmodels. The most effective units are high volumefilters that are installed under the sink.

Activated carbon treatment devices used forradon removal must treat all the water entering thehome, so entry-devices must be used. The minimumvolume of activated carbon needed for effective radonremoval is normally 1.5 cubic feet. However, this isgreatly dependent on the level of radon in the rawwater. In addition, some types of activated carbon aremore effective for radon removal than others.Consumers considering purchasing units for radonremoval should confirm that the dealer has experiencein this area.

The organic compound removal efficiency ofactivated carbon filters depends on the length of timecontaminated water is in contact with the activatedcarbon. Keeping the flow rate at the tap low willimprove the efficiency of an activated carbon filter.The greater the amount of carbon, the greater the con-taminant removal efficiency. For this reason, smallfilters that mount directly on the faucet are veryinefficient and should be avoided. For watercontaminated with organics, use only a filter with alarge volume.

To keep the unit operating properly, frequentreplacement of the filter cartridge is necessary.Replacements are usually needed once every sixmonths or after treating a certain amount of water,usually 300 to 1000 gallons. NSF-certified deviceswill list the time interval as well as the capacity on thedevice's data plate. Pour-through and faucet-mountedfilters need to have their filters replaced morefrequently. The manufacturer should be able toprovide data on the expected life of the filter for thecontaminants of concern. Devices that do not have thecapability to replace only the filter should be avoided.The life of the filter will be shortened significantly ifthe contaminant load increases or if the tap is usedmore than expected. If the filters are not replaced atthe required time, the amount of contaminants in thedrinking water can be greater than if no treatmentdevice was used.

Research has shown that activated carbon filterscan promote the growth of certain types of bacteria.The bacteria that grow on the carbon are usuallyharmless unless some type of contamination hasoccurred from the source water or contact withhumans during installation or replacement, etc. Thefollowing safeguards are recommended:

• Use activated carbon filters, without additionaldisinfection, only on a microbiologically safewater supply that is properly disinfected.

• Before using the device after a period of nonuse,such as overnight, run the water for 30 seconds orlonger at full flow before using. A longer flushingtime is recommended after a prolonged nonuseperiod of several days.

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• Change the filter cartridges at least as frequentlyas recommended by the manufacturer.

• Adhere to the manufacturer’s maintenancerecommendations and specific instructions onchanging the filter cartridges.

Activated Alumina Filters

The activated alumina process is very similar tothe activated carbon process. Water flows through acartridge containing a filter material consisting ofactivated alumina. The material has a large, highlyirregular surface area that removes contaminants fromthe water.

Activated alumina filters have been used toremove fluoride, arsenic and certain heavy metalsincluding lead, from drinking water. Since there areseveral different types of activated alumina, each withdifferent properties, the filter selected should be onedesigned to specifically remove the contaminant ofconcern.

As with activated carbon filters, the greater thevolume of filter media, the longer the life of thecartridge and the better the removal efficiency. Thefilters can experience problems with bacterial growthsimilar to carbon filters. The expected life of activatedalumina filters is similar to that of activated carbon.

The advantages of using activated alumina filtersare that they do not require electric power, asdistillation does, and do not use water, as reverseosmosis does. The purchase price of an activatedalumina unit also will be lower than either distillationor reverse osmosis treatment devices.

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However, activated alumina will not remove asmany contaminants as either of the other twoprocesses. As with other processes, periodic

replacement of the activated alumina filter cartridge isrequired.

Reverse Osmosis

Reverse-osmosis treatment devices use amembrane with pores small enough to screen outcontaminants. Pressure in the water line pushes waterthrough the pores in the membrane, while largecontaminant molecules are retained and eventuallywashed down the drain. No electrical power isrequired as the system operates from line pressure.Most reverse-osmosis devices are installed as point-of-use treatment.

Reverse osmosis is an effective method forremoving several different types of contaminants.Reverse osmosis can remove most inorganic materials(including lead, iron and chlorine) and some organicmaterials. Nitrate removal varies depending on thetype of membrane. Thin film composite membranesare more effective than cellulose acetate membranesfor nitrate removal. Point-of-use reverse-osmosis unitsoperate efficiently at water pressures above 40 poundsper square inch on raw waters with up to 2,000 mg/Lof total dissolved solids.

Factors affecting the performance of reverse-osmosis treatment devices include water pressure, typeof membrane, and the type and amount ofcontaminants. Several different types of reverse-osmosis membranes are available, but the mosteffective membranes are cellulose acetate and thin filmcomposite membranes. Membrane selection must bemade based on the type of contaminants to be removedand other water quality characteristics. Beforepurchasing a reverse-osmosis treatment system,consult the dealer or manufacturer about the type ofmembrane most suited for your particular needs.

Hardness can hinder the working of the reverse-osmosis membrane by clogging its pores, so it may benecessary to have a water softener before the reverse-osmosis unit where water is very hard. Several manu-facturers recommend that hardness levels not exceedten grains per gallon or 171 mg/L as CaCO3 when areverse-osmosis treatment unit is used. In addition,

some reverse osmosis membranes should not be usedon wells that contain high iron concentrations orcoliform bacteria. The manufacturer can supplyinformation regarding the level of hardness and ironthat the reverse-osmosis treatment device can tolerate.

High chlorine concentrations can damage somereverse-osmosis membranes, particularly thin filmcomposite membranes. Consult the dealer ormanufacturer to find out what chlorine levels the mem-brane can tolerate. If a reverse-osmosis treatmentdevice is used on a chlorinated water source, a carbonfilter should be utilized to remove chlorine from thewater prior to the reverse-osmosis unit. More frequentreplacement of the carbon filter is required in thesesituations to prevent premature failure of the moreexpensive reverse-osmosis membrane.

Complete reverse-osmosis treatment devicesgenerally come equipped with a mechanical pre-filterto remove sediment, a reverse-osmosis module thatcontains the membrane, an activated carbon filter toremove organics not removed by the reverse-osmosismodule, a pressurized storage tank and a special spigotfor the sink. Most reverse-osmosis units are mountedunder the sink where the greatest volume of drinkingwater is drawn and connected to the cold water linewith a line bypass. This type of installation does notprovide treated water throughout the home or building,but effectively can provide a very high degree of treat-ment to the two to five percent of household waterused for drinking and cooking.

All reverse-osmosis treatment devices contain adrain line which is connected to the sink drain throughwhich contaminants and minerals are continuallywashed with the rejected water. To preventcontamination of the treatment unit by the sanitarydrain, an approved air gap must be utilized betweenthe treatment unit and the drain. Be certain that the airgap is included as part of the installation. Reverse-osmosis units provide the home owner with finished

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water at 10 to 30 percent of the total water run throughthe system. Thus, a unit would require up to 20gallons of water to produce two gallons of finishedwater.

Removal efficiency with reverse osmosis isdependent on water pressure in the home. The higherthe pressure, the higher the level of contaminantremoval. Most homes have a tap pressure of at least40 psi, which should be sufficient for most reverse-osmosis treatment devices. For homes with lower

pressure, a booster pump may be needed for thereverse-osmosis treatment device to properly operate.

Proper maintenance is important. Mostmanufacturers recommend annual replacement of thefilters and replacement of the reverse-osmosis cartridgeevery one to five years. Reverse-osmosis is a veryeffective, although more expensive treatment method.Consumers should consider whether less expensivetreatment methods would meet their needs beforepurchasing reverse-osmosis units.

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Distillation

Distillation boils water to steam and then coolsthe steam until it condenses. The contaminants—metals, salt, sediment and anything else that will notboil or evaporate— are left behind in the boiling pot.The only contaminants that distillation will not removeare VOCs. Since VOCs have boiling points close tothat of water, they are carried off with the steam andend up in the distilled water. Some distillation unitscome equipped with a small activated carbon filterwhich is designed to remove VOCs from the distilledwater.

Distillers are made to rest on the countertop andbe filled manually or are installed under the sink, wherethey are connected to a cold water line.

Although distillation can be very effective atremoving a wide variety of contaminants, there are

several drawbacks with these systems. First,distillation devices need frequent maintenance.Minerals and other contaminants accumulate in theheating tank and form scale, which interferes with theheating process. If the home has hard water, theheating tank will have to be cleaned or flushedfrequently.

Distillers also use electricity to heat the water.Typical electric costs are 20 to 35 cents per gallon ofwater produced.

Another disadvantage is that distillation is a slowprocess. Most devices take at least five hours to makeone gallon of water. For these reasons, distillation israrely used as a home drinking water treatment device.

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Aeration

Home aeration systems primarily are used for theremoval of radon from drinking water. Radon isexclusively a problem where groundwater is used tosupply drinking water. Aeration also will reducevolatile organic chemical levels. Although aerationtreatment devices are costly to purchase and install, itis the best technology available for removing highradon levels.

The treatment device consists of a tank equippedwith a blower and a vent system. Water from the wellis sprayed into the aerator. Air flow from the blowerthen removes the radon, which is vented to the outsideof the house. Since radon is a gas, it is removed fairlyeasily by the induced air current in the tank.

After water leaves the aeration unit, it must berepressurized with a second pump. This means thathomes with individual wells may have to pump the

water twice. First, from the well into the home wherethe aeration tank is placed, and second, from the tankinto the home plumbing system. A second pressuretank may be required depending on how the homeplumbing system has been installed.

The vent pipe and flap from the aeration systemshould extend to the roof of the house so the radon willbe released at a level where it can not re-enter thehome or be inhaled by persons outside of the home.The blower will make noise comparable to that from aforced air furnace, so the unit should be placed in anisolated area if possible.

Depending on the water characteristics, the airflow in the tank may cause mineral coatings such asiron or calcium to form on the inside of the tank.Routine cleaning of the unit is necessary.

1. Water containing radon enters the top of the tankthrough a spray nozzle that turns the water into afine mist.

2. Air from the blower strips the radon from thewater.

3. The radon exits with the tank blowing air throughan air vent to the outside of the building.

4. Water leaving the tank must be repumpedbefore entering the household distributionsystem.

AERATION

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Chlorination

Chlorination systems are the only effective wayto handle large amounts of iron, hydrogen sulfide andcolloidal inorganics. Chlorination systems areeffective in eliminating bacterial contamination.Although in most cases it is more cost effective andsimpler to use an ultraviolet (UV) light disinfectionunit. This is true even when the water must be treatedfor turbidity removal prior to the UV treatment device.

A chlorination treatment device consists of achlorine solution tank, a chemical feeder, a retentiontank, a particulate filter and frequently an activatedcarbon filter. The homeowner prepares a solution ofsodium hypochlorite in a solution tank. Sodium hypo-chlorite is available in different strengths typically inthe 10 to 15 percent range, which is diluted whenplaced in the chemical solution tank.

The homeowner should purchase sodiumhypochlorite that is certified under ANSI/NSFStandard 60 as being acceptable for disinfection ofpotable water. The use of common household laundrybleach, which contains a 5.25 percent sodium hypo-chlorite solution, is not recommended, because thechemical purity of the product may not be suitable foraddition to drinking water. The solution is fed into thedrinking water by a chemical feed pump set to run withthe well pump. A retention tank is required whenusing chlorine systems to allow the contaminants toprecipitate and adequate contact time for properdisinfection. A detention time of 20 minutes is aminimum and, in many cases, a 30-minute detentiontime will be needed.

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Summary of Advantages, Disadvantages and Costs of Various Types of Entry/Use Treatment DevicesUltraviolet Light

Advantages: Effective for destroying bacteriaand viruses and disinfectingdrinking water.

Disadvantages: Will not remove contaminants otherthan bacteria and viruses.

Not effective for Giardia andCryptosporidium cyst removal.

Costs: Units typically cost between $300and $700.

Ion Exchange(excluding manganese greensand)

Advantages: Effective for removing mineralssuch as hardness, barium, radium,nitrate, sulfate, calcium andmagnesium. Effective for removingiron (provided concentrations donot exceed about 1 mg/L).

Disadvantages: Requires regeneration (usually withsodium chloride or potassiumchloride).

Costs: Typical costs vary from $500 to$1200 depending on the resin(anion exchange resins cost morethan cation exchange resins) andtype of equipment.

Mechanical Filters

Advantages: Effective for removing suspendedparticles such as rust, dirt and sedi-ment. Filters tested and approvedfor Giardia and Cryptosporidiumcysts are available.

Disadvantages: Not effective for removingdissolved contaminants such aslead, nitrate, VOCs, etc.

Costs: Use-device mechanical particulatefilters typically cost between $30and $100, with filter replacementcost of $15 to $40.

Activated Carbon Filters

Advantage: Effective at removing a wide rangeof organic contaminants such asVOCs and pesticides.

Carbon block and precoat designshave been validated as effective forlead reduction.

Often effective for reducing tasteand odor problems.

Does not use electricity or generatewastewater.

Disadvantages: Not effective at removing inorganicmaterials such as hardness, iron,nitrate or fluoride.

Bacteria growth may occur in thecarbon filter if not maintainedproperly.

May require post-disinfectionfacilities.

Costs: Point-of-Use activated carbonfilters typically cost between $75and $350. Replacement filter costis in the $20 to $40 range.

Point-of-Entry treatment devicestypically cost between $500 and$1,250. Replacement filters cost$200 to $400.

Activated Alumina Filters

Advantages: Effective for removal ofarsenic, fluoride and lead.Does not use electricityand does not waste water.

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Disadvantages: Will usually not remove mineralsother than those listed above.

Costs: Similar to activated carbon.

Reverse Osmosis

Advantages: Can remove a wide variety ofinorganic and organic contaminantsincluding lead, nitrate and sodium.

Normal household water pressureprovides good performance.

Disadvantages: Uses from three to five gallons ofwater for each gallon produced.

Some membranes are damaged bychlorine.

Costs: Under the sink use-devices thatinclude a mechanical prefilter andan activated carbon post filtertypically cost $400 to $1,000.Replacement membranes cost $30to $100.

Distillation

Advantages: Removes the greatest variety ofcontaminants.

Disadvantages: Uses approximately three kilowattsof electricity per gallon of water.

Water-cooled units waste aconsiderable amount of water.

Will require frequent cleaning,especially where the water is hard.

Removal of minerals may leavebland taste to the water.

Process is slow.

Costs: Between $99 and $500 for acountertop model.

Aeration

Advantages: Effective for removing radon andvolatile organic chemicals.

Disadvantages: Expensive to purchase and install.

Requires secondary pumping andpressurization.

Costs: Between $2,200 and $3,800.

Chlorination

Advantages: Only effective way of dealing withlarge amounts of iron, hydrogensulfide and colloidal iron.

Is also an excellent disinfectant.

Disadvantages: Requires handling and storage ofhazardous chemicals.

Requires time to insure thatchemicals are mixed properly andavailable when needed.

Costs: Between $800 and $1,500.

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APPENDIX A

List of Organizations Providing Information and Assistance to Consumers on HomeDrinking Water Treatment Devices.

1. NSF International. NSF International is a source of information on treatment devices and specificmanufacturer's products.

NSF International789 Dixboro Rd.Ann Arbor, MI 48113-0140800-NSF-MARK734-769-8010 or their website at http://www.nsf.org

2. Water Quality Association (WQA). WQA is an international trade association representing firms engaged inthe manufacture of water treatment equipment. WQA is a source of information on treatment devices and has avoluntary certification program for home treatment devices used for the treatment of nonhealth (i.e., aesthetic)related contaminants.

Water Quality Association4151 Naperville RoadLisle, IL 60532-1088630-505-0160 or their website at http://www.wqa.org

3. DEP Regional Offices. The regional offices of DEP are available to answer questions that you might haveconcerning the quality of your drinking water. The addresses and telephone numbers for the regional offices arelisted in Appendix B.

4. EPA’s Safe Drinking Water Hotline. This is a toll-free hotline that connects you to experts on drinking waterquality. Several free brochures are also available. The hotline is sponsored by EPA and can be reached at1-800-426-4791, Monday through Friday, 9:00 a.m. to 5:30 p.m. EST. Information about EPA’s Safe DrinkingWater Hotline can also be obtained at http://www.epa.gov/safewater.

5. National Pesticide Telecommunications Network. This is a toll-free hotline that can provide you withinformation on the health effects of particular pesticides and pesticide poisoning. The hotline is sponsored byEPA and can be reached 24 hours a day at 1-800-858-7378. Information about the National PesticideTelecommunications Network can also be obtained at http://www.nptn.orst.edu.

6. Penn State Cooperative Extension. The county office of Penn State Cooperative Extension has AgriculturalEngineering Fact Sheets on items such as Water Problems & Treatment, How to Disinfect a Water System,Intermediate Storage Water System and Iron Removal along with several others. Ask to speak to the waterquality agent or specialist to answer specific questions. Telephone numbers are listed in the government sectionof your phone directory. Information about the Penn State Cooperative Extension can also be obtained athttp://www.outreach.psu.edu/cooperative extension.

30

7. Consumer Reports magazine reviews different types of home treatment devices, most recently in the July 1995issue. Check your local library or order your own copy by contacting Consumer Reports, P.O. Box 53016,Boulder, CO 80322, 1-800-234-1645. Information about Consumer Reports can also be obtained athttp://www.consumerreports.org.

8. Better Business Bureau. The Better Business Bureau maintains records of unresolved complaints. Check tosee if there are any against the seller of water treatment devices. Consult your local telephone directory to findthe nearest office. Information on the Better Business Bureau can also be obtained through their website athttp://www.bbb.org.

9. The Pennsylvania Attorney General's Office, Bureau of Consumer Protection. The Bureau of ConsumerProtection, has a Consumer Protection Booklet which is available by calling the Consumer Protection Hotline at1-800-441-2555 or visit their website at http://www.oca.state.pa.us. The hotline can also provide guidance withparticular problems.

31

APPENDIX B

List of DEP Regional Offices and Counties ServedDEP Regional Offices Counties SupervisedSoutheast Region Bucks Delaware PhiladelphiaSuite 6010 Lee Park Chester Montgomery555 North LaneConshohocken, PA 19428Tel: 610-832-6059

Northeast Region Carbon Monroe Susquehanna2 Public Square Lackawanna Northampton WayneWilkes-Barre, PA 18711-0790 Lehigh Pike WyomingTel: 570-826-2511 Luzerne Schuylkill

Southcentral Region Adams Dauphin Lancaster909 Elmerton Ave. Bedford Franklin LebanonHarrisburg, PA 17110 Berks Fulton MifflinTel: 717-705-4708 Blair Huntingdon Perry

Cumberland Juniata York

Northcentral Region Bradford Columbia Snyder208 W. Third St., Suite 101 Cameron Lycoming SullivanWilliamsport, PA 17701 Centre Montour TiogaTel: 570-327-3675 Clearfield Northumberland Union

Clinton Potter

Southwest Region Allegheny Fayette Washington400 Waterfront Drive Armstrong Greene WestmorelandPittsburgh, PA 15222-4745 Beaver IndianaTel: 412-442-4217 Cambria Somerset

Northwest Region Butler Erie McKean230 Chestnut St. Clarion Forest MercerMeadville, PA 16335-3481 Crawford Jefferson VenangoTel: 814-332-6899 Elk Lawrence Warren

32

APPENDIX CPennsylvania Maximum Contaminant Levels

PRIMARY CONTAMINANTSVolatile Organic Chemicals (VOCs):Benzene ...............................................................................0.005 mg/LCarbon Tetrachloride ..........................................................0.005 mg/Lo-Dichlorobenzene ..............................................................0.6 mg/Lpara-Dichlorobenzene .........................................................0.075 mg/L1, 2-Dichloroethane.............................................................0.005 mg/L1, 1-Dichloroethylene..........................................................0.007 mg/Lcis - 1, 2-Dichloroethylene..................................................0.07 mg/Ltrans - 1, 2-Dichloroethylene ..............................................0.1 mg/LDichloromethane.................................................................0.005 mg/L1, 2-Dichloropropane ..........................................................0.005 mg/LEthylbenzene .......................................................................0.7 mg/L

Monochlorobenzene ............................................................0.1 mg/LStyrene.................................................................................0.1 mg/LTetrachloroethylene.............................................................0.005 mg/LToluene................................................................................1 mg/L1, 2, 4-Trichlorobenzene .....................................................0.07 mg/L1, 1, 1-Trichloroethane........................................................0.2 mg/L1, 1, 2-Trichloroethane........................................................0.005 mg/LTrichloroethylene ................................................................0.005 mg/LVinyl Chloride.....................................................................0.002 mg/LXylenes (Total)....................................................................10 mg/L

Synthetic Organic Chemicals (SOCs):Alachlor...............................................................................0.002 mg/LAtrazine ...............................................................................0.003 mg/LBenzo(a)Pyrene...................................................................0.0002 mg/LCarbofuran ..........................................................................0.04 mg/LChlordane ............................................................................0.002 mg/L2, 4-D ..................................................................................0.07 mg/LDalapon ...............................................................................0.2 mg/LDibromochloropropane (DBCP).........................................0.0002 mg/LDi (2-Ethylhexyl) Adipate ..................................................0.4 mg/LDi (2-Ethylhexyl) Phthalate................................................0.006 mg/LDinoseb................................................................................0.007 mg/LDiquat..................................................................................0.02 mg/LEndothall .............................................................................0.1 mg/LEndrin..................................................................................0.002 mg/LEthylene Dibromide (EDB) ................................................0.00005 mg/L

Glyphosate...........................................................................0.7 mg/LHeptachlor ...........................................................................0.0004 mg/LHeptachlor Epoxide.............................................................0.0002 mg/LHexachlorobenzene .............................................................0.001 mg/LHexachlorocyclopentadiene ................................................0.05 mg/LLindane................................................................................0.0002 mg/LMethoxychlor ......................................................................0.04 mg/LOxamyl (Vydate).................................................................0.2 mg/LPCBs....................................................................................0.0005 mg/LPentachlorophenol ...............................................................0.001 mg/LPicloram...............................................................................0.5mg/LSimazine ..............................................................................0.004 mg/L2, 3, 7, 8-TCDD (Dioxin) ...................................................3 x 10-8 mg/LToxaphene ...........................................................................0.003 mg/L2, 4, 5-TP (Silvex)...............................................................0.05 mg/L

Total Trihalomethanes (TTHMS):Total Trihalomethanes........................................................0.10 mg/L (Chloroform, Chlorodibromomethane, Bromoform & Bromodichloromethane)

Radionuclides:Gross Alpha........................................................................15 pCi/LCombined Radium (226 + 228)...........................................5 pCi/LBeta Particle & Photon Activity...........................................4 mrem/yrThe GROSS ALPHA MCL excludes Radon and Uranium particle activity.The BETA PARTICLE & PHOTON ACTIVITY MCL is for man-maderadionuclides.

Antimony................................................................................0.006 mg/LArsenic....................................................................................0.05 mg/LAsbestos..................................................................................7 million

fibers (longer than 10µm)/LBarium....................................................................................2 mg/LBeryllium ...............................................................................0.004 mg/LCadmium................................................................................0.005 mg/LChromium ..............................................................................0.1 mg/LCopper* ..................................................................................1.0 mg/LCyanide (free CN)..................................................................0.2 mg/L

Fluoride ..................................................................................2 mg/LLead* ......................................................................................0.005 mg/LMercury ..................................................................................0.002 mg/LNickel**..................................................................................Nitrate (as Nitrogen) ..............................................................10 mg/LNitrite (as Nitrogen) ...............................................................1 mg/LNitrate + Nitrite (as N)...........................................................10 mg/LSelenium.................................................................................0.05 mg/LThallium .................................................................................0.002 mg/L

*Lead and Copper Primary MCLs applicable only to Bottled, Vended, Retail and Bulk Water Hauling Systems** The nickel MCL was remanded for further evaluation. Monitoring for nickel remains in effect.

Microbiological Contaminants:Presence or absence of total coliforms based on number or percentage of total coliform-positive samples/month

orFecal Coliform or E. coli positive routine or check samples

TURBIDITY 1 NTU (Applicable only to unfiltered surface water sources)

SECONDARY CONTAMINANTSAluminum ..............................................................................0.2 mg/LChloride..................................................................................250 mg/LColor.......................................................................................15 color unitsCorrosivity.............................................................................. non-corrosiveFoaming Agents .....................................................................0.5 mg/LIron .........................................................................................0.3 mg/LManganese............................................................................0.05 mg/LOdor......................................................................................3 T.O.N.

pH***....................................................................................6.5-8.5Silver.....................................................................................0.1 mg/LSulfate.............................................................................. 250 mg/LTotal Dissolved Solids .................................................... 500 mg/LZinc.......................................................................................5 mg/L

Inorganic Chemicals (IOCs):

mg/L = milligrams per liter = parts per million; µm = micrometers; T.O.N. = threshold odor numberpCi/L = picocuries per liter (particle activity); mrem/yr = millirems/yr. (annual dose equivalent)***The pH MCL represents a “reasonable goal for drinking water quality.”

Bureau of Water Supply ManagementP.O. Box 8467

Harrisburg, PA 17105-8467

An Equal Opportunity Employer

3800-BK-DEP1367 Rev. 4/2000

This fact sheet and related environmental information are available electronically via Internet. For more information,visit us through the Pennsylvania homepage at http://www.state.pa.us or visit DEP directly athttp://www.dep.state.pa.us (choose directLINK “Drinking Water Publications”).

www.GreenWorksChannel.org - A web space dedicated to helping you learn how to protect andimprove the environment. The site features the largest collection of environmental videosavailable on the Internet and is produced by the nonprofit Environmental Fund for Pennsylvania,with financial support from the Pennsylvania Department of Environmental Protection, 800 334-3190.