Hundreds of thousands of gallons of water literally go down the drain each year from your household appliances. In fact, an average family of four uses 400 gallons every day, according to the Environmental Protection Agency (EPA).
You may have already tackled ways to pare your water use—from basic tasks like fixing a leaky toilet or sprinkler head to turning off a faucet when brushing teeth or washing dishes. But there’s another alternative: reusing your household waste water.
As water becomes increasingly precious–and expensive–and more areas of the country are facing droughts, there seems to be increasing interest in water systems that repurpose gray water (the generic term for water from showers, bathtubs, laundry and bathroom sinks ) in your home.
These gray water systems carry used water away from household appliances and clean it for use in irrigation (and, sometimes, for indoor plumbing uses like flushing toilets).
Gray water /noun/ Household wastewater (as from a sink or bath) that does not contain serious contaminants (as from toilets or diapers).
Nationally, outdoor water use accounts for 30 percent of household use, according to the EPA. And those numbers can skew higher, depending on the climate.
In Southern California, for instance, the Department of Water and Power calculates that irrigation represents 60 percent of water use for an average home, says Buzz Boettcher, managing member of Water Recycling Systems in Redondo Beach, Calif., a company that designs, builds, and installs water reuse systems.
So, how does a gray water system work? Boettcher says that used water is carried away from household appliances and sent via underground piping to a processor on your property for cleaning. There, the water is filtered, disinfected, pressurized, and sent into drip irrigation pipes to be held for a set period and then released to water lawns, trees, shrubs, flowers, or to wash cars and hose down hardscape.
Water from toilets, garbage disposals, and dishwashers (what’s known as “blackwater”) can’t be treated safely for reuse and instead must be sent separately to a sewer, he explains.
The gray water concept is still relatively new, and not all municipalities permit these systems to be installed in a residential setting, says Boettcher.
The biggest downside? It can be pricey—about $15,000 to purchase and install a complex system that distributes water to multiple zones or stores water for later use, Boettcher says. Flotender, a Seattle-based company, has similar pricing for multi-zoned systems, says company representative Justin Berkey. Both companies sell less expensive single-zone, or irrigation-only, systems.
How quickly costs are recouped depends on an area’s water fees, plus surcharges for sewage disposal, says Boettcher. Generally, a family of four with teenagers who might take long showers frequently could expect a payback within four to six years, he says.
Despite the significant outlay of funds, some homeowners may be more eager for the possibility: those who live in an area with a water shortage, whose community ordinances restrict irrigating yards, who purchase a new home in a city that requires it to be equipped from the get-go with this feature, as Tucson, Ariz., does; or those who simply want to be good eco-citizens.
Here’s what else you should know: