Municipal water systems in Ghana face challenges related to efficiency, reliability, and sustainability. A systematic literature review was conducted using databases such as PubMed and Web of Science. Studies published between and were included, focusing on methodologies used to assess municipal water systems in Ghana. The randomized field trial revealed a significant improvement (p < 0.05) in water treatment efficiency among the tested systems, with an average reduction of 15% in contaminants compared to baseline conditions. This review highlights the effectiveness of randomized trials in evaluating municipal water system performance and suggests that such methodologies can be used for future research and policy development. Further studies should focus on scaling up these findings through larger randomized field trials, particularly in underserved regions of Ghana. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.