Gray water is untreated residential wastewater that does not come from a toilet or garbage disposal (i.e., bathroom sink, bathtub, shower laundry, etc.). Gray water is regulated by the State of California, and a building permit must be obtained before installing a gray water system to collect and send this water to the resident’s landscaping, but water quality is not routinely monitored.

Recycled water, on the other hand, is water that is refined through several treatment processes to a level that is safe for a variety of beneficial uses. A number of regulatory agencies have adopted requirements that must be followed when producing, distributing, and using recycled water. Water quality is strictly monitored and routinely reported to the respective Regional Water Quality Board.