Cartas de aptidão para sistemas alternativos de esgotamento sanitários

The precariousness is a common situation for basic sanitation service in Brazil, especially in rural and isolated regions. This paper presents a set of charts defining conditions for of three different alternative sanitary sewage techniques for the rural area of ​​ Ribeirao do Meio Watershed (municipality of Leme-SP). Based on geotechnical characterization of the basin, we developed analysis identifying the most favorable areas for septic tanks, sumps and lagoons for wastewater disposal implementation. The map algebra operations consider the rocks, soils, conditions of water circulation, geodynamic features, relief and climate conditions. The attributes used were classified varying between favorable and restrictive conditions. The obtained charts do not suggest the best technique to be adopted, but the conditions for implementing each one. Results indicate that the area shows predominantly moderate conditions to septic tanks implementation, and a balance between favorable and moderate conditions for sumps and lagoons for wastewater disposal. The more decisive attributes in the area came from rocks conditions.