Sustainable Sanitation Systems: Understanding Priorities, Processes, and Pathways to Success

Summary

In resource-limited communities, sanitation systems experience frequent failure often due to a lack of community buy-in (acceptance) or the resource-intensive nature of sanitation operation and treatment processes. Studies in the past have focused on economic feasibility, environmental sustainability, or technology innovation without understanding the impacts of social behavior and implementation strategies on system performance. Sanitation systems that include resource recovery technologies, such as anaerobic digesters, could potentially reduce resource demands on communities through the production of biogas for electricity or digestate for fertilizer. However, such systems also experience high failure rates and user priorities for sanitation and recoverd resources (e.g., biogas, compost, water, urine for fertilizer) are not known. This research studies sanitation systems at the nexus of society and technology in order to elucidate community priorities and stakeholder engagement processes that together with technology strengthen system sustainability. Twenty resource-limited peri-urban slum resettlement communities in southern India are case studies for this work. This research seeks to:

identify community and sanitation priorities to better understand what communities value
evaluate the current ability and the potential of different sanitation technologies (conventional and resource recovery) to address community and sanitation priorities
analyze the combinations of social, technical, economic, and institutional factors that lead to successful and failed sanitation systems
evaluate the social, economic, and environmental aspects and overall relative sustainability of sanitation systems

For this research, we define a successful system as one that meets three criteria: (1) used correctly and daily by more than 75% of the community, (2) maintained correctly and adequately for at least 90% of required maintenance tasks, and (3) complies with local regulations for pH, BOD, and COD. A failed system does not meet one or more of the criteria for success. A sustainable system is a successful system that functions with minimal negative social, economic, and environmental life cycle impacts.

Funding

Mortenson Center in Engineering for Developing Communities Fellowship
Beverly Sears Graduate Research Grant

Research Context

Presently, India is home to the world’s fastest growing population but still faces some of the most significant challenges for successful sanitation systems. In India, more than 50% of sanitation systems have failed (Davis 2015) and 60% of the population lacks access to safely managed sanitation ��ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"2l4akjrpph","properties":{"formattedCitation":"(WHO and UNICEF 2017)","plainCitation":"(WHO and UNICEF 2017)"},"citationItems":[{"id":2151,"uris":["http://zotero.org/users/2666859/items/F84UCFNI"],"uri":["http://zotero.org/users/2666859/items/F84UCFNI"],"itemData":{"id":2151,"type":"report","title":"Progress on Drinking Water, Sanitation and Hygiene: Update and SDG Baselines","publisher":"Joint Monitoring Program","publisher-place":"Geneva","event-place":"Geneva","author":[{"family":"WHO","given":""},{"family":"UNICEF","given":""}],"issued":{"date-parts":["2017"]}}}],"schema":"https://github.com/citation-style-language/schema/raw/master/csl-citation.json"} (WHO and UNICEF 2017). Less than 20% of wastewater generated is treated ��ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"29ldd5sd9g","properties":{"formattedCitation":"(Kamyotra and Bhardwaj 2011)","plainCitation":"(Kamyotra and Bhardwaj 2011)"},"citationItems":[{"id":1296,"uris":["http://zotero.org/users/2666859/items/PPEPHKDE"],"uri":["http://zotero.org/users/2666859/items/PPEPHKDE"],"itemData":{"id":1296,"type":"article-journal","title":"Municipal wastewater management in India","container-title":"India Infrastructure Report","page":"299","source":"Google Scholar","author":[{"family":"Kamyotra","given":"J. S."},{"family":"Bhardwaj","given":"R. M."}],"issued":{"date-parts":["2011"]}}}],"schema":"https://github.com/citation-style-language/schema/raw/master/csl-citation.json"} (Kamyotra and Bhardwaj 2011), 67% of the country still uses biomass for cooking fuel, and 23% of the population lacks access to electricity ��ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"zZTz0oRA","properties":{"formattedCitation":"(WHO and UNICEF 2015)","plainCitation":"(WHO and UNICEF 2015)"},"citationItems":[{"id":256,"uris":["http://zotero.org/users/2666859/items/8XBQGDHN"],"uri":["http://zotero.org/users/2666859/items/8XBQGDHN"],"itemData":{"id":256,"type":"book","title":"Progress on sanitation and drinking water: 2015 Update and MDG Report","collection-title":"Joint Monitoring Programme","publisher":"World Health Organization","publisher-place":"Geneva","source":"Open WorldCat","event-place":"Geneva","ISBN":"92-4-150914-7","language":"English","author":[{"literal":"WHO"},{"literal":"UNICEF"}],"issued":{"date-parts":["2015"]}}}],"schema":"https://github.com/citation-style-language/schema/raw/master/csl-citation.json"} (WHO and UNICEF 2015). The central government has responded with ambitious national initiatives to increase sanitation access ��ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"14mhu8hs3","properties":{"formattedCitation":"(Government of India 2016)","plainCitation":"(Government of India 2016)"},"citationItems":[{"id":1670,"uris":["http://zotero.org/users/2666859/items/7P4XHCRS"],"uri":["http://zotero.org/users/2666859/items/7P4XHCRS"],"itemData":{"id":1670,"type":"webpage","title":"Swachh Bharat","container-title":"Swachh Bharat Mission \"My Clean India\"","URL":"https://swachhbharat.mygov.in/","author":[{"family":"Government of India","given":""}],"issued":{"date-parts":["2016"]},"accessed":{"date-parts":["2016",9,9]}}}],"schema":"https://github.com/citation-style-language/schema/raw/master/csl-citation.json"} (Government of India 2016) and electrify the country ��ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"CTcRzm1j","properties":{"formattedCitation":"(Mangaldas 2017)","plainCitation":"(Mangaldas 2017)"},"citationItems":[{"id":2536,"uris":["http://zotero.org/users/2666859/items/HMZAHN7E"],"uri":["http://zotero.org/users/2666859/items/HMZAHN7E"],"itemData":{"id":2536,"type":"webpage","title":"Power To The People: India Plans To Electrify 40 Million Households By 2018","container-title":"Forbes","URL":"https://www.forbes.com/sites/leezamangaldas/2017/09/27/power-to-the-people-india-plans-to-electrify-40-million-households-by-2018/#3d16a86618f7","author":[{"family":"Mangaldas","given":"Leeza"}],"issued":{"date-parts":["2017",9,27]},"accessed":{"date-parts":["2017",10,10]}}}],"schema":"https://github.com/citation-style-language/schema/raw/master/csl-citation.json"} (Mangaldas 2017) in the next two years, but, to avoid continued failure of these new initiatives, there is a need to analyze and understand the individual and combinations of factors that lead to success and failure.�� To evaluate priorities, pathways to success and failure, and sustainability for sanitation in resource-limited contexts, we analyzed 20 resource-limited communities in Karnataka and Tamil Nadu, India. Communities had comparable populations and demographics; the communities are all peri-urban settlements where residents are day laborers, low income, and from India’s lowest caste, dalit. The sanitation systems serve between 800 and 1000 users and are all shared, community-managed systems. Half of the communities had successful systems and half had failed systems. Additionally, half of the systems included resource recovery technologies and half did not. Resource recovery technologies included DEWATS (a type of decentralized wastewater treatment system with a biogas digester, baffled reactor, and gravel filter), Ecological Sanitation (EcoSan) urine diverting dry toilets, and improved septic tanks with gravel filters. Non-resource recovery technologies include DEWATS (with settling tanks instead of digesters), and septic tanks with gravel filters.

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Research Methods

We employed a phased, mixed-methods approach that included��in-depth case studies, cross-case comparative analysis, and sustainability assessments for 10 communities with conventional sanitation systems (e.g., primary settlers and secondary filters) and 10 communities with resource recovery systems (e.g., anaerobic digesters) in India.��Phase 1��we conducted semi-structured interviews, focus groups, and photovoice to elicit community and sanitation priorities��and evaluate how well current technologies meet priorities and the potential for technologies to better meet priorities. We employed the Analytical Hierarchy Process (AHP) in focus groups to create ranked lists of sanitation and community priorities.��Phase 2��used semi-structured interviews, observations, documentation, and technical evaluations to characterize existing system conditions and implementation strategies for sanitation systems. Data was coded using QSR NVivo, a qualitative coding software and calibrated for each condition and outcome.��Fuzzy-set Qualitative Comparative Analysis (fsQCA) was used to determine the existing community conditions that in combination or isolation lead to system outcomes of success and failure.��Phase 3 evaluated established sustainability frameworks��to understand how sustainability is defined and measured, and use the frameworks on ten cases that were analyzed.��

Findings

The outcomes of this research included:

Identification of the most effective methods to identify community and sanitation priorities
Identification of community and sanitation priorities
Evaluation of how well existing systems address priorities
Quantification of the potential of different conventional and resource recovery technologies to better address community and sanitation priorities
Pathways to successful and failed sanitation systems that combine community priorities assessment, stakeholder engagement methods, and infrastructure designs��
Comparison of sanitation sustainability frameworks from research and practice to understand how sustainability is measured
Recommendations to implementing organizations to improve sanitation system implementation and stakeholder engagement