Lack of reliable water quality data is leading to serious global health issues. The UNEP estimates that around 3 billion people are at health risk due to scarcity of water quality data, which mainly stems from the lack of resources such as testing labs and manpower. In this project, we will explore the use of low-cost water testers and evaluate their efficacy in accurately mapping the quality of river water in Goan rivers (India) using an open-source, citizen science-based approach.