Aquatic quality watch informed by communities (AQWIC) facilitating the adoption of low-cost sensor systems for underserved communities: a review and tutorial

This tutorial review addresses the growing need for accessible water quality monitoring in rivers, lakes, and other surface waters. While commercial monitoring systems effectively serve water utilities and regulatory agencies, many communities lack the resources for regular water quality assessment. We present approaches for developing low-cost monitoring systems specifically designed for community-based environmental monitoring programs, citizen science initiatives, and educational applications. Through systematic analysis of 84 peer-reviewed papers on low-cost water quality monitoring, we identify key implementation approaches, common challenges, and successful design strategies. This analysis informs our tutorial recommendations and provides evidence-based guidance for system development. Specifically, we introduce a web-based portal AQWIC - Aquatic Quality Watch Informed by Communities. This open-source portal includes (1) tutorials on how to construct, program, and deploy water quality sensor systems using commercially available, low-cost components; and (2) an interactive water quality database where users can input their collected water quality data with geolocation. We highlight the functionality of AQWIC and review a set of commercially available low-cost water sensors through several deployments both in the United States and Colombia. The sensor module used is capable of measuring conductivity, temperature, pH, and turbidity, providing a cost-effective alternative to traditional testing methods. Our findings demonstrate that the conductivity, temperature, and pH sensors offer reliable and consistent results, aligning with conventional testing methods over several week periods. However, we also observed limitations in the accuracy of the turbidity sensor, emphasizing the need for improved precision at lower turbidity levels. By offering a cost-effective and user-friendly approach to real-time water quality monitoring, this work aims to empower communities to monitor and characterize their water quality and makes significant strides toward ensuring equitable access to safe water for all.