Grey Water Systems

Grey water is water from your bathroom sinks, showers, tubs, and washing machines which comprise 50-80% of residential "waste" water. It is not water that has come into contact with feces, either from the toilet or from washing diapers. Greywater may contain traces of dirt, food, grease, hair, and certain household cleaning products. While grey water may look "dirty", it is a safe and even beneficial source of irrigation water in a yard. There are many simple, economical ways to reuse greywater in the landscape.

It's a waste to irrigate with great quantities of drinking water when plants thrive on used water containing small bits of compost. Unlike a lot of ecological stopgap measures, greywater reuse is a part of the fundamental solution to many ecological problems and will probably remain essentially unchanged in the distant future. The benefits of greywater recycling include:

• Lower fresh water use

Grey water can replace fresh water in many instances, saving money and increasing the effective water supply in regions where irrigation is needed. Residential water use is almost evenly split between indoor and outdoor. All except toilet water could be recycled outdoors, achieving the same result with significantly less water diverted from nature. When the weather is warm, about half of the water consumed by the average household is for outdoor use. Capturing the indoor greywater for use outdoors can cut water usage in half.

Less strain on septic tank or treatment plant

Greywater use greatly extends the useful life and capacity of septic systems.

• Highly effective purification

Greywater is purified to a high degree in the upper, most biologically active region of the soil. This protects the quality of natural surface and ground waters.

• Sites unsuitable for a septic tank

A greywater recycling system, along with the use of composting toilets, can enable the development of property that is unsuitable for a septic system. For sites with slow soil percolation or other problems, a greywater system can be a partial or complete substitute for a very costly, over-engineered system.

• Less energy and chemical use

Less energy and chemicals are used due to the reduced amount of both freshwater and wastewater that needs pumping and treatment. For those providing their own water or electricity, the advantage of a reduced burden on the infrastructure is felt directly. Also, treating your wastewater in the soil under your own fruit trees definitely encourages the dumping of fewer toxic chemicals down the drain.

• Groundwater recharge

Greywater application in excess of plant needs recharges groundwater.

• Plant growth

Greywater enables a landscape to flourish where water may not otherwise be available to support much plant growth. The nutrients in the greywater are broken down by bacteria in the soil and made available to plants. This helps to maintain soil fertility.

• Reclamation of otherwise wasted nutrients

Loss of nutrients through wastewater disposal in rivers or oceans is a subtle, but highly significant form of erosion. Reclaiming nutrients in greywater helps to maintain the fertility of the land.

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