When recycled for drinking, the millions of gallons of water that Bay Area residents flush down toilets and showers every day could be cleaner than the pristine Hetch Hetchy water that flows from many taps in the region, according to a top California water official. … Recycled water for human consumption … will be so clean that workers will have to add minerals to it, because the purification process strips the water of necessary minerals that make it drinkable. But recycling the region’s used water for drinking, a process called “direct potable reuse,” is not happening anywhere in the Bay Area — at least not yet.