If you are a fan of Elizabeth Royte's writing, you will want to drink up her story in the New York Times magazine about her visit to the Orange County Groundwater Replenishment System, where they take sewage, clean it and pump it back into the ground to top up the water supply.
"I gazed balefully at my hotel toilet in Santa Ana, Calif., and contemplated an entirely new cycle. When you flush in Santa Ana, the waste makes its way to the sewage-treatment plant nearby in Fountain Valley, then sluices not to the ocean but to a plant that superfilters the liquid until it is cleaner than rainwater. The "new" water is then pumped 13 miles north and discharged into a small lake, where it percolates into the earth. Local utilities pump water from this aquifer and deliver it to the sinks and showers of 2.3 million customers. It is now drinking water. If you like the idea, you call it indirect potable reuse. If the idea revolts you, you call it toilet to tap." ::New York Times
More on Elizabeth Royte in TreeHugger:
Book Review: Bottlemania
Garbage Land- a Review
TreeHugger on Toilet to Tap
Recycling Water for Drinking
Care for a Drink... of Toilet Water?