Ceilidh P. Welch, Sydney P. Rudko , Bradley Peter , Sarah Klimchuk, Kazvinder Gill , Robert X. Lu, Patrick C Hanington 

Quantitative polymerase chain reaction (qPCR) is increasingly used in recreational water quality monitoring, yet the temporal variability of indicator concentrations as well as the breadth of locations and biological hazards to be monitored continues to present a challenge. Participatory approaches such as community-based monitoring (CBM) are valued in environmental research but the potential for the integration of DNA-based methods has yet to be realized. This study assessed the reliability of a decentralized, community-based qPCR monitoring program for fecal indicator bacteria, Enterococcus spp., in recreational waters. Non-expert community partners were responsible for DNA extraction and qPCR analysis of samples at a satellite laboratory; training, protocols, and materials were provided and standardized by our research team. Comparison of community partner results to those from duplicate samples analyzed by our research team following U.S. EPA Method 1611 revealed a high level of reliability, with 72.8% of community partner results indicating the same beach management decision as Method 1611. Median coefficient of variation between community partner and Method 1611 results ranged from 7.07% to 10.29%. In this study, we demonstrate the ability of non-expert community partners to independently carry out protocols and to generate reliable qPCR monitoring data for water quality indicators and the strong relationship between the results of this community-based approach and gold standard methods. As the employment of DNA-based testing expands, incorporation of these techniques into a CBM framework presents a means to advance and expand traditional monitoring and research approaches by increasing capacity, addressing gaps, fostering greater inclusivity and community engagement in monitoring and management, and improving the accessibility of environmental research.