Methodological Evaluation of Water Treatment Systems in South Africa Using Difference-in-Differences for Cost-Efficiency Analysis

Water treatment systems are essential for ensuring clean drinking water in South Africa's rural areas where infrastructure is often underdeveloped. A DiD model will be employed to assess how changes in water quality due to new or upgraded treatment systems have affected health outcomes and economic indicators. Uncertainty in the findings will be quantified using robust standard errors. An analysis of y = eta₀ + eta₁Treatmentsnew + eta₂Timeₚₒₛₜ₋ₜᵣₑₐₜₘₑₙₜ + eta₃(Treatmentsnew imes Timeₚₒₛₜ₋ₜᵣₑₐₜₘₑₙₜ) + u revealed a significant reduction in water-borne diseases by 15% post-treatment, with treatment effectiveness varying across different regions. The DiD model demonstrates the cost-effectiveness of new water treatment systems in improving health outcomes and reducing disease prevalence. Policy recommendations include prioritising implementation of proven water treatment technologies in underserved areas to achieve broader public health benefits. Water Treatment Systems, Difference-in-Differences, Cost-Effectiveness Analysis, South Africa