Water treatment facilities in Kenya face challenges related to cost-effectiveness and sustainability. A randomized controlled trial was conducted across five districts in Kenya. Participants were randomly assigned to either receive standard or alternative water treatment facilities for a period of six months. The analysis revealed that the alternative water treatment systems reduced waterborne diseases by 30% compared to the standard systems, with an estimated cost-effectiveness ratio of $5 per disease prevented. The study provides evidence on the cost-benefit of different water treatment technologies in Kenya's context. Investment decisions should consider not only initial costs but also long-term health and financial outcomes. The maintenance outcome was modelled as $Y_{it}=\beta_0+\beta_1X_{it}+u_i+\varepsilon_{it}$, with robustness checked using heteroskedasticity-consistent errors.