In Guinea, community-based water quality monitoring has been implemented to improve drinking water safety in rural areas. A mixed-method approach combining qualitative interviews with quantitative surveys was employed, ensuring representation from diverse socio-economic backgrounds across Guinea’s regions. Community members reported a significant decrease in water-related illnesses (52% reduction) after the monitoring programme began. Water quality parameters improved notably, especially in areas with higher participation rates. The replication study confirms the positive impact of community-based water quality monitoring on drinking water safety, emphasising its importance for public health interventions. Governments and international organizations should support ongoing monitoring programmes to sustain these benefits and scale up successful initiatives. community-based water quality monitoring, Guinea, drinking water safety, public health intervention Model estimation used $\hat{\theta}=argmin_{\theta}\sum_i\ell(y_i,f_\theta(x_i))+\lambda\lVert\theta\rVert_2^2$, with performance evaluated using out-of-sample error.