As Greywater Becomes More Mainstream, Health Concerns Lessen

For the homeowner, saving water usually means cutting back on shower time, planting drought-tolerant vegetation or installing low-flow toilets. But some residents in water-strapped states are taking things further, tapping into washing machines and showers to irrigate fruit trees, cut down on sewer outflow and save money.

The use of greywater, wastewater generated from showers, sinks and washing machines, is on the rise, but it's large-scale implementation has been slow. Costly permits and confusing building codes have hampered ambitious homeowners. But grass-roots activists have taken things into their own hands and today's Blog Action Day, all about water, is a good time to highlight their efforts.

One group leading the charge is the Oakland-based Greywater Action, which provides workshops, seminars and educational events designed to teach people how to conserve and reuse water and install greywater systems.

They group previously called themselves the Greywater Guerillas, so named because their DIY-approach to bringing household water out to the yard often violated numerous California plumbing codes.

Many of the regulations related to greywater are focused on health. Greywater can contain bacterial pathogens, causing health departments to worry over public safety risks. But some savvy health agencies are realizing how useful reused water can be. The GreyWater Alliance, an offshoot of Greywater Action, recently hosted a seminar entitled "Perceived Versus Actual Risks: Greywater and Pathogens," attended by environmental health professionals from the City of Berkeley and San Francisco.

Health concerns noted by some of the panelists included cross contamination of clean drinking water with greywater. Pooled water can also lead to a nice spot for mosquitoes to breed, leading to increases in vector-borne disease. But proper installation and maintainence of greywater systems can eliminate both these concerns.

Residents with greywater systems also have to be more conscientious about what goes down the drain, since chemicals will end up, at least in some part, in their yards. The Greywater Action suggests biodegradable soaps and those free of borox (which can kill plants).

Greywater should never come from toilets and it isn't okay to ingest. Proper plumbing to the outdoors is meant to limit overall contact with it. Two of the main principles of healthy greywater systems are that is must pass slowly thought topsoil to allow for natural purification and a design that prevents greywater-to-human contact to occur before this step.

Even with many users taking it upon themselves to experiment with reuse of water, the reward to risk ratio is very high. According to Oasis Design, there are eight million greywater systems set up in the U.S., in operation for decades, and there has not been one documented case of greywater transmitted illness.

As for reward, a report from UCLA estimates that if 10 percent of Southern California implemented greywater systems for laundry, showers and dishwashers, the water savings would be equal or greater than the capacity of a large seawater desalination plant. All that from hooking up a pipe to the clothes washer!

With many states revising their building codes to make installing greywater systems easier, they are likely to flourish. California's greywater code recently made it easier for people to install legal systems. A city in Texas is looking to initiate a greywater ordinance, and Habit for Humanity recently installed a water reuse system in Tuscon.

Since the much of household water can be reused, every city should have a greywater programs set up to encourage water conservation, before its too late.

Photo credit: laszlo-photo