“Toilet to tap” is the less-than-appealing nickname given to wastewater that is treated so it can be recycled for human use. For about a decade now, Orange County has had a plant that purifies wastewater and pumps it back into the groundwater supply. And as the county expands its operations, it is working to convince the public that the water is indeed clean and safe to drink. On a scorching first day of summer, the Orange County Water District set up a stand in Hollywood to give away free ice-cold bottled water.