Embodiments of the present invention provide a system to direct water flow through a lavatory and to cleanse grey water through a series of treatment steps. The water may then be re-directed to the faucet for re-use in hand washing or other potable water use or to the toilet for flush water. The treatment steps are altered, depending upon the ultimate use of the water, as flush water need not be treated to the same level as potable water. The system may also function via a cascade of logic commands given by a series of electronic controllers, valves, and sensors which are fine-tuned to supply enough water to each component of the system.