If it will be around, neutral water; of 6 for low acid and 8 for basic top. a river that is not considered healthful it does not present these characteristics for some reasons, being in its majority caused by the man. But the pollution that we enxergamos is that one caused by the sewer of the houses, that launches in the rivers the food remaining portion and a type of bacterium that of them if it feeds: they are the calls aerbicas bacteria, them they consume oxygen and they destroy the life aquatic and moreover they can cause health problems will have been ingested. This water starts to be considers contaminated water that is that one that transmits illnesses, therefore beyond containing microorganisms, remaining portions of animals, larvae and eggs of worms, this water is not potable, then it does not have to be used. The water poluda is different of the contaminated water, therefore this is that one that has smells fort, well dark color, that modified its natural characteristics, that is, left of being pure and healthful for the beings livings creature.

The substances that if they mix in the water are called pollutant agents who very make badly to the beings livings creature. Poluda with contaminated water is very common the people to confuse water, and a river can have its contaminated waters and poludas at the same time. The contaminated water or poluda is harmful to the health, because this water can contain pathogenic organisms or chemical substances capable to cause illnesses to the man being these called illnesses of hdrica propagation, and to use has it that to submit it procesos of very expensive purificao. 2.2 Which are the pollution forms the water suffer to contamination for the calls sources from contamination, the supplying water pass for a rigorous treatment e, only later, are distributed for the residences, where linkings exist domiciliary.