Batho ba bangata ba thahasella boleng le polokeho ea metsi a nooang. Kaha linōka le matša li silafatsoa habonolo ke litšila tsa indasteri le metsi a phallang a tsoang libakeng tsa temo, metsi a ka tlas’a lefatše ke mohloli o ka sehloohong oa metsi a nooang a boleng bo phahameng. Leha ho le joalo, metsi a joalo hase kamehla a sireletsehileng. Liliba tse ngata, mehloli ea metsi a nooang, le tsona li silafetse. Kajeno, tšilafalo ea metsi e nkoa e le e ’ngoe ea litšokelo tse khōlō bophelong bo botle. Lintho tse silafatsang tse fumanehang ka metsing ke lihlahisoa tse tsoang tšebetsong ea ho bolaea likokoana-hloko ka chlorine. Lihlahisoa tsena li eketsa kotsi ea ho tšoaroa ke kankere ea senya le mala. Bakhachane ba jang boholo ba lihlahisoa tsena ba kotsing e kholo ea ho senyeheloa ke mpa. Metsi a nooang a ka ba le li-nitrate. Mehloli ea nitrate metsing a ka tlas'a lefatše (ho kenyeletsoa le liliba tsa poraefete) hangata ke litšila tsa temo, menontsha ea lik'hemik'hale le manyolo a tsoang libakeng tsa ho fepa. 'Meleng oa motho, li-nitrate li ka fetoloa li-nitrosamine, li-carcinogens. Metsi a kopanang le liphaephe tsa khale le solder ea loto manonyeletsong a liphaephe a tlala loto, haholo-holo haeba a futhumetse, a na le oxid kapa a le bonolo. Bana ba nang le loto e ngata ea mali ba ka ’na ba e-ba le mathata a kang ho holofala, ho holofala ho ithuta, mathata a boitšoaro le khaello ea mali. Ho pepesehela loto ho boetse ho lebisa kotsing e eketsehileng ea mafu a ho ba le bana. Metsi a silafetseng a boetse a tletse maloetse a kang cryptosporidiosis. Matšoao a eona ke ho nyekeloa ke pelo, letšollo le boemo bo kang ba ntaramane. Matšoao ana a tsoela pele ka matsatsi a supileng ho isa ho a leshome. Cryptosporidium parvum, protozoan e ikarabellang bakeng sa ho ata ha cryptosporidiosis, hangata e teng matšeng le linokeng tse silafalitsoeng ke likhoerekhoere kapa litšila tsa liphoofolo. Sebōpuoa sena se na le khanyetso e phahameng ea chlorine le likokoana-hloko tse ling. E ka baka mafu le haeba e kena 'meleng oa motho ka bongata bo sa lokelang. Metsi a belang ke mokhoa o sebetsang ka ho fetisisa oa ho fokotsa Cryptosporidium parvum. Metsi a pompo a ka hloekisoa ho tsoa ho ona ka lebaka la ho khutlisa osmosis kapa ho sebelisa sefe e khethehileng. Ho ameha ka chefo e bolaeang likokoanyana, loto, lihlahisoa tsa chlorination ea metsi, metsoako ea liindasteri, nitrate, polychlorinated biphenyl le litšila tse ling tsa metsi ho entse hore bareki ba bangata ba rate metsi a libotlolo, ba lumela hore a phetse hantle, a hloekile ebile a sireletsehile. Metsi a libotlolo a fumaneha ka mefuta e fapaneng.
Metsi a selemo, a rekisoang haholo ka libotlolo, ke metsi a tsoang mehloling e ka tlas'a lefatše. Ho lumeloa hore mehloli e joalo ha e na tšilafalo, le hoja sena se belaela. Mohloli o mong oa metsi a nooang ke metsi a pompo, ’me hangata a tšeloa ka meriana e bolaeang likokoana-hloko kapa e sefiloeng pele a tšeloa ka libotlolong. Ka tloaelo, metsi a hloekisitsoeng a hloekisoa kapa a kenngoa ho osmosis e fapaneng kapa mokhoa o tšoanang. Leha ho le joalo lebaka le ka sehloohong la ho tsebahala ha metsi a libotlolo ke tatso ea eona, eseng bohloeki. Metsi a libotlolo a tšeloa likokoana-hloko ka ozone, e leng khase e sa sieeng tatso ea ka morao, kahoo a latsoeha ho feta metsi a chlorine. Empa na metsi a libotlolo a phahametse metsi a pompo tabeng ea bohloeki le polokeho? Ho hang. Metsi a libotlolo ha se hakaalo hore a finyella litekanyetso tse phahameng tsa bophelo bo botle ho feta metsi a pompo. Lipatlisiso li bontša hore mefuta e mengata ea metsi a ka libotlolong e na le lik’hemik’hale tse tšoanang le lintho tse hlahisoang ke metsi a pompong, tse kang trihalomethanes, nitrate le li-ion tse kotsi tsa tšepe. Hoo e ka bang kotara ea metsi ohle a libotlolong a rekisoang ke metsi a pompo a hloekisitsoeng a fumanoang phepelong ea metsi ea sechaba. Libotlolo tsa polasetiki, tseo ho tsona metsi a leng teng, li tlatsetsa sebopeho sa eona ka bongata ba metsoako e kotsi bophelong. Batho ba sebelisang li-filters ba lokela ho hopola hore lihloela li hloka tlhokomelo e nepahetseng 'me li lokela ho nkeloa sebaka ke nako nako le nako. Kaha metsi a hloekileng a bohlokoa bakeng sa 'mele, boleng ba metsi a sebelisoang e lokela ho ba ntho ea bohlokoa bakeng sa bophelo bo botle. Re lokela ho etsa sohle se matleng a rona ho sireletsa mehloli ea metsi a nooang tšilafalong.