Wastewater (Grey water)

"Grey water" is wastewater collected from clothes washers, bathtubs, showers, and laundry or bathroom sinks. If properly collected and stored, it can be safely re-used, thereby reducing fresh water consumption. Reuse of gray water can also reduce the load on septic tanks and leach fields.

Grey water is distinguished from "black water", which is wastewater from toilets, kitchen sinks and dishwashers. Black water should never be reused in the home because of possible contamination by bacteria, viruses, and other pathogens.

The benefits of grey water recycling:

• 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.

• Less strain on septic tank or treatment plant

Grey water use greatly extends the useful life and capacity of septic systems. For municipal treatment systems, decreased wastewater flow means higher treatment effectiveness and lower costs.

• Highly effective purification

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

• Site unsuitable for a septic tank

For sites with slow soil percolation or other problems, a grey water 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 you to dump fewer toxic chemicals down the drain.

• Groundwater recharge

Grey water application in excess of plant needs recharges groundwater.

• Plant growth

Grey water enables a landscape to flourish where water may not otherwise be available to support much plant growth.

• 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 grey water helps to maintain the fertility of the land.

• Increased awareness of and sensitivity to natural cycles

Grey water use yields the satisfaction of taking responsibility for the wise husbandry of an important resource.