Reuse-Oriented Decentralized Wastewater and Sewage Sludge Treatment for Small Urbanized Rural Settlements in Brazil: An Environmental Cost-Benefit Analysis

Abstract

Latin-American countries lack efficient solutions for wastewater and sewage sludge treatment. In particular, small urbanized rural settlements (SURUS) in many of these countries face significant challenges with respect to the selection and operation of sustainable sewage treatment facilities. Decentralized sanitation and reuse (DESAR) solutions can significantly contribute toward the improvement of wastewater sanitation coverage in SURUS in Latin-American regions. The major advantages of DESAR for SURUS are a reduction in final treatment costs because these systems allow for water reclamation and sewage sludge reuse for agriculture. To reflect the applicability of DESAR on a regional scale, we present here an integrative assessment, including a cost-benefit analysis (CBA) and geographic information systems (GIS) surveying, as a "decision support methodology" for conducting environmental-economic analyses. As a case study, this methodology was applied to six SURUS located at the Rio Dois Rios basin of Rio de Janeiro state. The CBA shows that DESAR could recover between 15% and 34% of total operational and maintenance costs for SURUS populations between 222 and 1,585 inhabitants. The findings suggest that DESAR systems can respond to the need to reduce costs and improve nutrient recovery capabilities of sanitation interventions in rural communities.