Performance of Anaerobic Baffled Reactor for Decentralized Wastewater Treatment in Urban Malang, Indonesia

In order to assess the impact of the Sanitation by Communities (SANIMAS) program for community-led sanitation in Indonesia (established in 2002), this research work was conducted with the aim of characterizing the current performance of anaerobic baffled reactors (ABRs), which were deployed in high numbers for the provision of domestic wastewater treatment in densely populated urban areas in Malang (Indonesia). Small and decentralized sewage treatment facilities serve ⇡3% of the total population in Malang, including 89 ABR treatment plants. Our findings reveal that only 14% of the 89 ABRs in Malang have an acceptable performance with regard to pollutant removal and integrity of their building structure, but the majority of them produce a treated effluent of poor quality, according to discharge consents set by the Ministry of Environment and Forestry of the Republic of Indonesia (Regulation No. P.68/2016). Clearly the lack of consistent operation and maintenance practices have had a detrimental effect on these decentralized sewage treatment systems, despite their robustness and buffer capacity to cope with changes in organic and hydraulic loading rates. Urbanization will continue to exert pressure on the provision of sanitation services in lower and middle economies, and the role of decentralized sewage management systems is expected to be prominent in the UN’s Sustainable Development Goals era (2015–2030); however, sustainable service delivery must be conceived beyond the provision of sanitation infrastructure