An average American family uses more than 300 gal. of water a day, according to the U.S. Environmental Protection Agency (EPA), more than half of which will eventually exit showers, sinks, and the washing machine. In most households, “greywater” from these sources leaves the house in the same drain as the “blackwater” from flushing toilets, and that’s where Laura Allen has a bone to pick with conventional attitudes.
Allen, who helped found an educational non-profit called Greywater Action, has spent the last 20 years promoting residential plumbing systems that capture greywater and use it for landscape irrigation. She wishes more builders, plumbers, and homeowners would embrace the idea that greywater is a valuable and underused resource—not sewage.
“Some people are really entrenched in that mindset,” Allen said in a telephone call from her home in Oregon. “And now we’re saying: Take out this stream of what you say is wastewater and put it out in your landscape. It goes against what a lot of people consider fundamental training. For some people, it can be really challenging to acknowledge that.”
Residential greywater systems run the gamut from simple, gravity-powered irrigation lines for backyard plantings all the way to fully automatic devices that treat greywater for flushing toilets or topping off the backyard swimming pool. There is no national policy on greywater use. The EPA offers some general information about water reuse and conservation, but greywater regulations are on a state-by-state basis. In some states, homeowners can install simple systems without a permit and for relatively little money. In others, an engineer’s stamp may be required to get greywater plumbing approved by local inspectors. Only about half of all states have adopted rules guiding the design of greywater systems.
Although greywater isn’t loaded with the same kind of bacteria…