What is Grey Water?

Grey water refers to untreated, gently used water waste from bathroom faucets, bathtubs, showers and clothes washers that is otherwise directed to the sewer. The water has not come into contact with contaminated sources such as toilet waste, kitchen sink or dishwasher waste. Grey water is captured, treated and reused for non-potable uses such as landscape irrigation, car washing and toilet flushing. At the CRD’s Fisgard location, rainwater collected from roof drains is used to flush half the building’s toilets.

Grey water must be treated and disinfected before storage and reuse to reduce the number of pathogens that spread disease and begin to turn septic and smell. Watering restrictions typically do not apply for grey water irrigation.

Before a shower, save the water that would otherwise go down the drain with a bucket. Collected water can then be used to water indoor and outdoor plants.

Benefits of Grey Water Recycling

  • Save money on water bill
  • Use less treated drinking water
  • Reduce pressure on waste water treatment
  • Reduce pollution going into waterways
  • Delay expansion of drinking water and waste water treatment infrastructure

Considerations

  • Depending on the greywater recycling system, the payback period may extend past the lifespan of the system
  • Grey water systems must meet municipal and provincial regulations and building code
  • Systems must be align with Health Canada Guidelines for Domestic Reclaimed Water for Use in Toilet and Urinal Flushing
  • Potential cross connections with potable water lines must be properly controlled so that the potable water supply is not contaminated
  • Landscape irrigation systems using grey water must be designed by a professional or a Registered Onsite Wastewater Practitioner, and filing documents must be submitted to the Health Authority
  • Grey water should only be used for non-food crops
  • Grey water is considered sewage – when it leaves a building, it must be disposed of in accordance with the sewerage system regulation

Resources

Provision of this information does not represent an endorsement by the CRD of the conclusions reached by studies or a recommendation of any of products or techniques.

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