Impact of mental models on constructed wetland maintenance in semi-arid India

Constructed wetlands (CWs) are a low-cost technology relying on natural processes to treat wastewater and provide a decentralized wastewater treatment option in communities with limited infrastructure. Little is known about their long-term maintenance or monitoring, or the experience of communities who adopt and maintain CWs. This research uses mental models to compare the perspectives of scientists and community members regarding CW maintenance. Forty-three semi-structured interviews with farmers, maintainers, local politicians, CW neighbors, extension agents, and scientists in four villages in south India were conducted. Differences in their mental models reveal the importance of understanding CW ecology, the connection between CW maintenance and treated effluent water quality, and how to monitor and maintain the CW. The results contradict the commonly accepted idea that CWs are a simple technology that is easily maintained. CWs are complex and their complexities need to be factored into decision-making related to choosing what WW treatment is most appropriate in the rural communities for which they are being considered. The study's results highlight the need for radical re-design of CWs so they do not need maintenance or can be maintained intuitively by community members.