Clarity tubes as effective citizen science tools for monitoring wastewater treatment works and rivers

Graham, Mark and Pattinson, Nicholas and Lepheana, Ayanda and Taylor, Jim, Clarity Tubes as Effective Citizen Science Tools for Monitoring Wastewater Treatment Works and Rivers (December 12, 2023). Available at SSRN: https://ssrn.com/abstract=4662221 or http://dx.doi.org/10.2139/ssrn.4662221

Improved freshwater resource management requires implementing widespread, effective, and timeous water quality monitoring. Conventional monitoring methods are often inhibited by financial, infrastructural, and human capacity limitations, especially in developing regions. This study aimed to validate the citizen-scientist operated transparency / clarity tube (hereafter ‘clarity tube’) for measuring water clarity as a proxy for total suspended solids (TSS) concentration, a critical quality metric, in river systems and wastewater treatment work (WWTW) effluent in Southern Africa. Clarity tubes provided a relatively accurate and precise proxy for TSS in riverine lotic systems and WWTW effluent, showing significant inverse log-linear relationships between clarity and TSS with r2 = 0.715 and r2 = 0.51, respectively. We demonstrate that clarity-derived estimates of TSS concentration (TSScde) can be used to estimate WWTW compliance with WWTW effluent TSS concentration regulations. The measurements can then be used to engage with WWTW management, potentially affecting WWTW performance. Overall, these findings demonstrate the usefulness of clarity tubes as low-cost, accessible, and easy-to-use citizen science tools for high spatial and temporal resolution water quality monitoring, not only in rivers in Southern Africa, but in WWTW effluent for estimating compliance, with strong global relevance to the Sustainable Development Goals (SDGs).