The Use of Appropriate Sanitation Technology in Low-Income and Informally Occupied Areas: A Case Study of EMBASA’s Experience With the Condominial Sewerage System in Salvador da Bahia, Brazil

Abstract

This article describes how the State of Bahia Water and Sanitation Company (Empresa Baiana de Águas e Saneamento [EMBASA]) expanded sewerage coverage in the city of Salvador, in the state of Bahia, Brazil. In 2021, the city had a sewerage network that served over 80% of its population, despite the fact that at least 70% of the city was composed of informal settlements. To overcome the enormous challenges of installing sewerage systems in areas with informal settlements, EMBASA decided to use the condominial sewerage model, a methodology that combines technical changes in the design of the collection systems coupled with a strong community participation component. The principal technical changes in the collection system were adapting the solution to local circumstances in each neighborhood, universalization of service, the use of the concept of microsystems (subbasins), and the use of the urban block as the basic collection unit. The methodology was first used during a program to expand the sanitary sewerage system of Salvador between 1995 and 2004, when household connections to the sanitary sewage system increased from 26% to 60% in the municipality. The condominial sewerage methodology was adopted because it was the only system capable of solving the enormous problems of informal occupation, community participation, and social inequality, among other things. With the success of the program, investments in sanitary sewerage were continued, and in 2021, the connection rate was 81%. Many challenges to increasing coverage remained, especially those related to the occupation of urban land, which continued in a disorderly manner; social inequalities; and changes in the sanitation regulatory framework.