A system for converting urine into potable water for drinking and use in a hand washing station (165) comprises a commode (100), a three-way valve (110) at the outlet of the commode, a urine reactants tank (145), a storage container (160), a pump (170), and a spigot (175). A user turns an actuator (111) on the valve in one direction to direct feces and feces-plus-urine into a reactants tank for feces, and in another direction to direct urine into the urine reactants tank. The urine reactants tank contains a plurality of baffles (210) separating the tank into chambers. A first chamber contains algae and microorganisms supplied by a seed (150). These organisms absorb nutrients from the urine as they grow into a mass (152). A last chamber contains only purified water which flows from the tank into the storage container from which it can be pumped to the spigot.