Hey Mr. Green,
There are a lot of folks who live outside urban areas and have private wells and septic systems. How green are these? Doesn't this essentially recycle the water we consume and flush?
--J. Lennon in Wake Forest, North Carolina
More than 20 percent of the country's households use septic systems. They are the basic choice where there is no municipal sewage system, although I suppose a composting toilet is the ultimate green sewer machine (some are even designed to capture the methane from the waste to burn in stoves). To be on the cutting edge of sludge, you can explore various models on the internet.
Of course, septic tanks have to be pumped out periodically and should be set up to avoid the risks of health problems or water pollution. But if they’re properly designed and installed, I don't see a problem. Since some of the tanks’ water seeps back into the ground, they actually do recycle. For a wealth of information, visit the EPA's website. Your tax dollars at work!
Whatever system you're on, flush minimally so as not to waste water. In my long-ago farm childhood, we had an old outdoor toilet. It was a used model, its wooden walls laced with graffiti so vivid that it jump-started my literary career. When we finally obtained the long-anticipated indoor alternative, my father enforced minimal flushing because of his concern that the well would go dry. With water, as with everything else, the old-timers practiced reduce, reuse, and recycle long before that phrase became an axiom.
Other water-conservation tools that could be used, whether you live in the middle of nowhere or the middle of Manhattan, are: low-flow toilets, restricted-flow showerheads, aerator screens on faucets, smaller lawns and minimal lawn watering, drip irrigation, use of native plants instead of thirsty exotics, and washing machines and dishwashers run with full loads only. (And yes, a modern dishwasher uses a lot less water than a typical hand-washing process.) It goes without saying that you should make sure no faucets leak.
Some people even collect rainwater and use "gray water" (from showers and laundry) on their gardens. But if you attempt these measures, make sure there aren't toxic materials on your roof or in gutters that would contaminate the water – and that the gray water is safe for your plants.