Two teams of investigators sought sites in the Philippine Islands where selected water-disinfection devices could be installed for evaluation. Selection criteria were based on the need for disinfection, technical, political, and logistical considerations. It is concluded that the specific disinfection devices which were to be evaluated are not suitable for conditions existing at most locations in the Philippines at this time. It is possible that one or more of them might have utility if installed during the construction or reconstruction of a system, but retrofit to existing systems is not practical.