Gray water makes up approximately 50% of the average household’s wastewater. Re-using gray water not only cuts your potable water costs but also helps reduce the energy demand and chemical use for treating that water.
Gray water is wastewater from bathroom sinks, showers, bathtubs and clothes washers. In Texas, up to 400 gallons of gray water per day can be re-used for subsurface irrigation or to stabilize foundations. It can also be treated for other applications where locally allowable.
Both the state and the city have rules that govern how gray water systems are designed, installed and operated. The City of Austin requires a permit and a system designed by a Texas-licensed professional engineer or plumber.