Hard wat er is wat er t hat cont ains an appreciat ive quant it y of dissolved m inerals ( like calcium and m agnesium

) - Soft wat er is t r eat ed w at er in which t he only ion is sodium . As rainwat er falls, it is nat urally soft . How ev er , as wat er m akes it s way t hrough t he ground and int o our wat erways, it picks up m inerals like chalk, lim e and m ost ly calcium and m agnesium . Since hard wat er cont ains essent ial m inerals, it is som et im es t he pr efer red drinking wat er, not only because of t he healt h benefit s, but also t he flavor . On t he ot her hand, soft wat er t ast es salt y and is som et im es not suit able for drinking. So why, t hen, do w e soft en our wat er ? When it boils down, t he m aj or difference bet w een hard and soft wat er can best be seen while doing household chores. Hard wat er is t o blam e for dingy looking clot hes, dishes wit h spot s and r esidue and bat ht ubs wit h lot s of film and soap scum . Even hair washed in hard wat er m ay feel st icky and look dull. Hard wat er can t ake a t oll on household appliances as well, using up m or e energy. The elem ent s of hard wat er are t o blam e for all of t hese negat ive fact ors, as soap is less effect ive due t o it s react ion t o t he m agnesium and calcium . The lat her is not as rich and bubbly. Chor e- doer s will love using soft wat er, as t asks can act ually be perform ed m or e efficient ly wit h it . Soap will lat her bet t er and it em s will be left cleaner . Glasses will sparkle and hair will look healt hy. The shower curt ain will be scum - free. Clot hes and skin are left soft er. I n addit ion t o t im e, t his can also save m oney, as less soap and det ergent s will be used. Since appliances have t o w ork less hard, soft wat er can also pr olong t he life of washing m achines, dishwat ers and wat er heat er s. Energy bills are not iceably lower when in households wit h wat er soft ener s. I n a t im e of rising energy cost s, t his is som et hing t o t hink about . Soft wat er is not , how ever, suggest ed for t hose wit h heart or circulat ory problem s, or ot hers who m ay be on a low sodium diet . I n t he soft ening process, as m inerals are r em oved, sodium cont ent increases. Resear ch show s t hat cardiovascular disease has t he lowest risk in ar eas where wat er has t he m ost m ineral cont ent . TH E BEST OF BOTH W ORLD S: A SOLUTI ON Ther e ar e way s t o com bat t he sodium in soft wat er, which will allow households t o enj oy bet t er t ast ing wat er , as well as have t he best available wat er for cleaning needs. They ar e r e ve r se osm osis , dist illat ion and deionizat ion. What t ype is y our wat er ? The Wat er Qualit y Associat ion of t he Unit ed St at es defines hard wat er as having dissolved m ineral hardness of 1 GPG ( grain per gallon) or m or e. Here is a helpful t able t o show t he hardness of wat er: Soft Wat er- less t han 1 gpg Slight ly Hard- 1- 3.5 gpg Moderat ely Hard- 3.5- 7 gpg Ver y Hard- 7- 10 gpg Ext r em ely Hard- ov er 10 gpg

Drinking wat er, including bot t led wat er , m ay r easonably be expect ed t o cont ain at least sm all am ount s of som e cont am inant s. U.S. EPA set s st andards for appr oxim at ely 90 cont am inant s in drinking wat er. Cont am inant s are cat egorized as below and m or e det ailed inform at ion on specific cont am inant s is also available. M icr obe s ~ Ra dionuclide s ~ I nor ga nics ~ V ola t ile Or ga nics ~ D isinfe ct a nt s ~ D isinf e ct ion By pr oduct s ~ M TBE

Microbes
Colifor m ba ct e r ia are com m on in t he environm ent and ar e generally not harm ful. How ev er, t he pr esence of t hese bact eria in drinking wat er is usually a result of a pr oblem wit h t he t reat m ent syst em or t he pipes which dist ribut e wat er , and indicat es t hat t he w at er m ay be cont am inat ed wit h germ s t hat can cause disease. Fe ca l Colifor m a n d E coli ar e bact eria whose presence indicat es t hat t he wat er m ay be cont am inat ed wit h hum an or anim al wast es. Micr obes in t hese wast es can cause short - t er m effect s, such as diarr hea, cram ps, nausea, headaches, or ot her sym pt om s. Tur bidit y has no healt h effect s. How ev er, t urbidit y can int erfer e wit h disinfect ion and provide a m edium for m icrobial growt h. Turbidit y m ay indicat e t he pr esence of disease causing organism s. These or ganism s include bact eria, viruses, and parasit es t hat can cause sym pt om s such as nausea, cram ps, diarrhea, and associat ed headaches. Cr ypt ospor idium is a parasit e t hat ent ers lakes and river s t hr ough sewage and anim al wast e. I t causes crypt osporidiosis, a m ild gast r oint est inal disease. How ev er , t he disease can be sever e or fat al for people wit h sev erely w eak ened im m une sy st em s. EPA and CDC have pr epar ed advice for t hose wit h severely com pr om ised im m une sy st em s who are concerned about Cry pt osporidium . Gia r dia la m blia is a parasit e t hat ent ers lakes and rivers t hrough sewage and anim al wast e. I t causes gast roint est inal illness ( e.g. diarrhea, vom it ing, cram ps) .

Radionuclides
Alph a e m it t e r s. Cert ain m inerals are radioact ive and m ay em it a form of radiat ion know n as alpha radiat ion. Som e people who drink wat er cont aining alpha em it t ers in excess of EPAs st andard ov er m any years m ay have an increased risk of get t ing cancer. Be t a / phot on e m it t e r s. Cert ain m inerals are r adioact ive and m ay em it form s of radiat ion known as phot ons and bet a radiat ion. Som e people who drink wat er cont aining bet a and phot on em it t er s in excess of EPAs st andard over m any y ears m ay hav e an increased risk of get t ing cancer . Com bine d Ra dium 2 2 6 / 2 2 8 . Som e people w ho drink wat er cont aining radium 226 or 228 in excess of EPAs

st andard over m any y ears m ay hav e an increased risk of get t ing cancer . Ra don gas can dissolve and accum ulat e in underground wat er sources, such as w ells, and in t he air in your hom e. Br eat hing radon can cause lung cancer . Drinking wat er cont aining radon present s a risk of dev eloping cancer. Radon in air is m or e danger ous t han radon in wat er.

I norganic Cont am inant s

Ant im ony Asbest os Barium Beryllium Cadm ium Chrom ium Copper Cyanide Lead Mercury Nit rat e/ Nit rit e Selenium Thallium

Ar se n ic. Som e people who drink wat er cont aining arsenic in excess of EPAs st andard over m any years could experience skin dam age or pr oblem s wit h t heir circulat ory sy st em , and m ay have an increased risk of get t ing cancer. Fluor ide . Many com m unit ies add fluoride t o t heir drinking wat er t o pr om ot e dent al healt h. Each com m unit y m akes it s own decision about whet her or not t o add fluoride. EPA has set an enforceable drinking wat er st andard for fluoride of 4 m g/ L ( som e people who drink wat er cont aining fluoride in excess of t his level ov er m any y ear s could get bone disease, including pain and t enderness of t he bones) . EPA has also set a secondary fluoride st andard of 2 m g/ L t o prot ect against dent al fluor osis. Dent al fluorosis, in it s m oderat e or sever e form s, m ay result in a brown st aining and/ or pit t ing of t he perm anent t eet h. This pr oblem occur s only in developing t eet h, befor e t hey erupt from t he gum s. Children under nine should not drink wat er t hat has m or e t han 2 m g/ L of fluoride. Le a d t ypically leaches int o wat er fr om plum bing in older buildings. Lead pipes and plum bing fit t ings have been banned since August 1998. Children and pr egnant wom en ar e m ost suscept ible t o lead healt h risks. For advice on av oiding lead, see t he how t o r em ove lead in your drinking wat er fact sheet pr epar ed by EPA.

Volat ile Organic Cont am inant s ( VOCs)

Benzene Carbon Tet rachloride Chlorobenzene o- Dichlorobenzene* * p- Dichlorobenzene 1,1- Dichloroet hylene cis- 1,2- Dichloroet hylene t rans- 1,2- Dicholoroet hylene Dichlorom et hane 1,2- Dichloroet hane 1,2- Dichloropropane Et hylbenzene St yrene Tet rachloroet hylene 1,2,4- Trichlorobenzene 1,1,1,- Trichloroet hane 1,1,2- Trichloroet hane Trichloroet hylene Toluene Vinyl Chloride Xylenes

Disinfect ant s
Many wat er supplier s add a disinfect ant t o drinking wat er t o kill germ s such as giardia and

e coli . Especially aft er heavy rainst orm s, y our w at er syst em m ay add m or e disinfect ant t o guar ant ee t hat t hese germ s ar e killed. Chlor ine . Som e people who use drinking wat er cont aining chlorine well in excess of EPAs st andard could experience irrit at ing effect s t o t heir ey es and nose. Som e people who drink wat er cont aining chlorine well in excess of EPAs st andar d could experience st om ach discom fort . Chlor a m ine . Som e people who use drinking wat er cont aining chloram ines well in excess of EPAs st andard could experience irrit at ing effect s t o t heir ey es and nose. Som e people who drink wat er cont aining chloram ines w ell in excess of EPAs st andar d could experience st om ach discom fort or anem ia. Chlor ine D iox ide . Som e infant s and young children who drink wat er cont aining chlorine dioxide in excess of EPAs st andard could ex perience nerv ous syst em effect s. Sim ilar effect s m ay occur in fet uses of pregnant wom en who drink wat er cont aining chlorine dioxide in excess of EPAs st andard. Som e people m ay experience anem ia.

Disinfect ion Byproduct s

Disinfect ion bypr oduct s for m when disinfect ant s added t o drinking wat er t o kill ger m s react wit h nat urallyoccuring organic m at t er in wat er. Tot a l Tr iha lom e t h a ne s. Som e people who drink wat er cont aining t rihalom et hanes in excess of EPAs st andard ov er m any y ear s m ay experience problem s wit h t heir liver, kidneys, or cent ral nerv ous syst em s, and m ay hav e an increased risk of get t ing cancer. H a loa ce t ic Acids. Som e people who drink wat er cont aining haloacet ic acids in excess of EPAs st andard ov er m any years m ay have an increased risk of get t ing cancer. Br om a t e . Som e people who drink wat er cont aining brom at e in excess of EPAs st andard ov er m any years m ay have an increased risk of get t ing cancer. Chlor it e . Som e infant s and young children who drink wat er cont aining chlorit e in excess of EPAs st andard could experience nerv ous syst em effect s. Sim ilar effect s m ay occur in fet uses of pr egnant wom en who drink wat er cont aining chlorit e in excess of EPAs st andard. Som e people m ay experience anem ia.

MTBE
M TBE is a fuel addit ive, com m only used in t he Unit ed St at es t o reduce carbon m onoxide and ozone lev els caused by aut o em issions. Due t o it s widespr ead use, r eport s of MTBE det ect ions in t he nat ions gr ound and surface wat er supplies are increasing. The Office of Wat er and ot her EPA offices are working wit h a panel of leading expert s t o focus on issues posed by t he cont inued use of MTBE and ot her oxygenat es in gasoline. EPA is curr ent ly st udying t he im plicat ions of set t ing a drinking wat er st andard for MTBE.Drinking wat er, including bot t led wat er , m ay r easonably be expect ed t o cont ain at least sm all am ount s of som e cont am inant s.
As part of t he Drinking Wat er and Healt h pages, t his fact sheet is part of a larger U.S. EPA publicat ion: EPA Nat ional Prim ary Drinking Wat er Regulat ions