This paper addresses two questions: (1) what is the most desirable form of sanitizing chemical for use in rural water supplies; and (2) what is the best overall means of getting this sanitizing agent into rural water supplies? Several chemicals and hydrochlorinators are described and evaluated. In conclusion, a low-cost dependable feeding device suitable for use in disinfecting marginal waters in the rural areas of developing countries is presented. The operation and maintenance is low skilled and does not require a sophisticated power source.