Applying Water Resource Management Tools to Plan A Decentralized Sewage Treatment System Using Constructed Wetland

Lessandro Morini Trindade

Lessandro Morini Trindade Federal University of Rio Grande do Sul, Brazil

Abstract: The study proposes, in the water management framework, to use tools to plan a decentralized, complementary wastewater treatment, using septic tank (ST) followed by vertical flow constructed wetland (VFCW), in the aim of revitalizing urban watercourses. These technologies are low-impact and have a reduced implementation cost, not requiring large areas and being able to to efficiently reduce organic load. The area of study was the Mãe d’Água dam microbasin, with approximately 3.38 km² in area and population of 18,632, located between the cities of Viamão and Porto Alegre/RS. This is an urban area with no local sanitary infrastructure. We used tools such as the Ishikawa diagram, fieldwork and geographic information system (GIS) to produce thematic maps, operational analysis methods and sizing and cost of decentralization. The use of geoprocessing was essential to determine the ideal area to project the installation of the sewage treatment system. For a group of 30 people, the proposal was viable, but the one for four people presented limitations, such as: subjectivity for some tools; ST with VFCW resulted in high costs, not meeting the goal of reduced implementation cost.