{ "background": "Inadequate risk governance frameworks often impede the reliable performance of engineered water treatment systems in sub-Saharan Africa, despite significant infrastructure investment. Current evaluations frequently lack rigorous, field-based causal inference linking system operations to quantifiable health risk reduction.", "purpose and objectives": "This policy analysis aims to develop and demonstrate a quasi-experimental methodology for the diagnostic evaluation of water treatment facility performance and its associated risk governance protocols. The objective is to provide a replicable framework for isolating the causal effect of system interventions on water quality outcomes.", "methodology": "A difference-in-differences quasi-experimental design was applied, comparing faecal coliform levels in intervention and control clusters before and after governance interventions. The core statistical model is $Y{it} = \\beta0 + \\beta1 \\text{Treat}i + \\beta2 \\text{Post}t + \\delta (\\text{Treat}i \\cdot \\text{Post}t) + \\epsilon_{it}$, where $\\delta$ captures the causal effect. Robust standard errors were clustered at the facility level to account for serial correlation.", "findings": "The analysis found that enhanced governance interventions, specifically the introduction of performance-linked maintenance contracts, were associated with a 34% reduction in mean faecal coliform counts at treatment outputs. The estimated coefficient $\\delta$ was -0.42 (95% CI: -0.68 to -0.16), indicating a statistically significant improvement. Key themes from ancillary qualitative data highlighted the critical role of clear accountability structures.", "conclusion": "Quasi-experimental designs offer a robust methodological tool for engineering policy analysis, moving beyond descriptive performance audits to causal attribution. The applied diagnostic framework successfully quantified the risk reduction efficacy of specific governance mechanisms within the water treatment sector.", "recommendations": "Integrate quasi-experimental diagnostics into national water utility regulatory reporting. Policy should mandate the establishment of control groups for evaluating major system upgrades. Funding for treatment infrastructure should be contingent on the implementation