How To Use Graywater
(Page 3 of 4)
May/June 2001
By Carol Steinfeld
Using graywater also requires a consciousness of what is put down the drain—toxic chemicals, drain cleaners, and strong disinfectants must be avoided.
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Is it legal?
As both regulators and property owners come to accept the merits of graywater recycling, it is going public. Many graywater systems—some legal and some not so legal—have been installed in California, the first state to enact graywater regulations and promote graywater’s use during droughts. Now several others, including Massachusetts, Arizona, and Washington, are following this lead, and more will likely come on board as the laws relax and system costs decrease.
Is it foolproof?
Careful design and planning is key, or your graywater experience may go sour. Inadequate ventilation of indoor systems can lead to unpleasant odors. Using soil in a graywater system is another common mistake, Del Porto explains. Carbon from soaps, detergents, and body oils can clog the soil, making it anaerobic, foul-smelling, and ineffective. “You need air spaces for aerobic transformation and nitrogen to avoid carbon buildup that will clog the soil,” he explains. “That’s why chunky sand and other large and porous growing media are best.”
Graywater at work
Ludwig, whose small Santa Barbara home features an Eden-like variety of fruit trees irrigated with graywater, says that few of the graywater systems he designs get legal approval because of the cost and complication of meeting codes. An exception is a “branched drain system” that he designed for a neighboring home, which distributes graywater under eight inches of soil (in the root zones of plants) in a yard filled with fruit trees. Basins of mulch provide more aerobic treatment and evaporation.
In a central Massachusetts home, graywater irrigates an aerobic planter bed containing thirsty tropicals such as banana trees, birds of paradise, bamboo, and bougainvillea. The entire system is housed in a greenhouse that also helps heat the home. “The owners are thrilled,” says Del Porto, the system’s designer. “They didn’t know that such a system was possible.”
Del Porto’s firm designs systems for clients whose homes in environmentally sensitive areas require nonpolluting wastewater solutions. Many clients learn about such systems when touring his ecologically retrofitted home near Boston. Outside the home, a bed of evergreen shrubs is irrigated by filtered graywater from Del Porto’s washing machine. Within a two-story attached solar greenhouse, graywater from some of the home’s sinks is filtered, treated in aerobic planter beds, and then drained to a fountain and pond containing koi fish and water hyacinths.