Recent studies suggest that water-sanitation technologies in schools can improve child health metrics such as diarrhoea incidence and undernutrition levels. The research employs a mixed-methods approach combining quantitative data from school health surveys and qualitative interviews with teachers and parents. A multivariate regression model will be used to analyse the impact of water-sanitation technologies on child health metrics. A significant reduction in diarrhoea incidence was observed among children who benefited from improved water-sanitation facilities, demonstrating a decline by approximately 25%. The findings indicate that implementing water-sanitation technologies in South African schools can lead to substantial improvements in child health metrics, particularly reducing the prevalence of diarrhoea. Based on these results, public health authorities and school management should prioritise the provision of water-sanitation facilities to enhance children's health outcomes. Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.