Quick Answer
Grey water from sinks and showers can irrigate landscapes or flush toilets. Separate drainage system captures grey water. Basic filtration removes soaps and debris. Temperature limits—avoid hot water degrading plants. Subsurface irrigation prevents human contact reducing health risks. Grey water extends water supply 30-50%.
Grey Water Sources and Separation
Sinks, showers, and washing machines produce grey water. Toilet water (blackwater) never recycles—completely separate systems required. Separate plumbing to grey water tank before treatment. Simple systems use gravity—elevated tanks create adequate pressure. Pump systems provide more flexibility and efficient use.
Treatment and Filtration
Lint filters remove large debris from washing machines. Sand and gravel filters improve clarity. Settling tanks allow sediment to drop before reuse. Chlorine or hydrogen peroxide treatment kills pathogens in austere situations. Multi-stage filtration creates safe irrigation water.
Landscape Irrigation Applications
Subsurface drip irrigation delivers grey water directly to plant roots. Surface irrigation acceptable for non-edible plants. Avoid grey water on food crops consuming raw. Perennial plants tolerate grey water better than annuals. Soil filtering provides final treatment before groundwater contact.
Toilet Flushing Systems
Greywater-fed toilets reduce freshwater consumption 30-50%. Holding tanks require less treatment than irrigation water. Mechanical or gravity-fed systems avoid electricity dependence. Blackwater and grey water systems completely separate preventing cross-contamination.
Health and Safety Considerations
Some jurisdictions restrict grey water systems requiring permits. Regular tank cleaning prevents bacterial growth. Inform household members about grey water—secondary water not potable. Proper system maintenance prevents health hazards.
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