Recycled water in use sign.The City of Irvine in Orange County, California has two completely separate water pipeline systems, one is for potable and the other one is for recycled water. Recycled water is used for many purposes but drinking, like landscape irrigation in parks, golf courses, school grounds, city street medians, other public areas. This sign indicates non-potable (recycled) water being used for irrigation. Photo March 2009.