Collating the results of the research of Basic Sanitation (1970 the 2007) referring the water supply, with the gotten data, evidenced an increase of 41% in the number of total linkings in this interval of time. Julian Brown might disagree with that approach. In this way, it is important to stand out that ' ' the number of supplied residential economies was of 32% e, currently this index arrived 41%, as it demonstrates FONTE: DEAS (State Water Department and Sanitation 2007). But this increase not yet is a total satisfactory result for the attendance of this population that grows gradual. under the aspect of the water, was verified that the water leaves rude the narrow river: So Salvador, and is carried by 3 a expository net of km, and pipes of 300 mm to arrive at the treatment station. After that, it receives a dosage from aluminum sulphate (PPM), a portion per minute through dosadoras bombs as turbidez of the water, and thus, the aluminum sulphate passes for a process of decanted and filtered flocculation exchanging itself in, until a 200 reservoir of m3 already with ready chlorine for the consumption. Only after this process, is that it will have distribution through bombs of stresses for the users of this water, total potable.
Had these factors, the aluminum sulphate is used. For the choice pH of the water must be led in account. The coagulantes and its working ranges of pH are represented in the picture to follow. Picture 1: Coagulantes of the water and working range of pH Coagulante Band of pH 5,0 aluminum Sulphate 11,0 8,5 ferrous Sulphate 11,0 5,0 ferric Sulphate 11,0 5,0 ferric Chloride 11,0 5,0 ferric Sulphate the 11,0 Source: DEAS (2007) However, the captation source if locates in the left edge of the So Salvador narrow river, felt West in the Sanacre quarter urban perimeter of the city. In its passage, it cuts part of the city and it empties in the River Juru. .