Interesting article on where your water might come from, especially if you live in California and other dry areas:
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.
Fascinating. And, for those who are homeschooling, a visit to your local waste water reclamation plant is an educational and enlightening experience. Give them a call and schedule a field trip.