Guardian: Orange County's waste water facility is the world's biggest treatment plant, pumping 70m gallons of water a day to recharge groundwater levels. Now the state which is in the midst of a historic drought is expanding the plant. The $140m expansion will recycle 100m gallons of water a day and provide water to an additional 250,000 residents in the state. Suzanne Goldenberg visits the Fountain Valley plant and takes a sip of the treated water