Grey Water Recycling

Grey Water Recycling

Grey Water Recycling refers to water that is recovered as a by-product of cleaning and other uses in the hotel environment and then reused in the same functions or other purposes like garden irrigation. Care must also be taking to ensure that the recycled water does not contain harmful toxins that may present a health and safety risk to your guests and the environment. These contaminants typically include bacteria, suspended and/or, dissolved solids, acids, alkalises and synthetic bacteria. The Water Act (1998), states that it is illegal to discharge contaminated wastewater to the sewerage and storm water systems.

The Grey Water recycling system is made up of one or more tanks that includes a filtration system. The size is dependent on what process is needed to recycle the water and how much water can be recycled. Systems are available for all types of hospitality establishments (eg large hotels, lodges, B&B’s and guest houses). A well designed piping system serviced by a pump will ensure that the system works economically. Depending on the water flow rate, some systems employ mechanical filtration to remove the suspended dirt to protect downstream equipment such as valves.  If needed, additional treatment to remove or protect specific Greywater contents may include sand filtration, bleach, ozone or UV light.

What you need to know:

  • Total water consumption can be dramatically reduced
  • Depending on the type of system and the cost of water in the region, a payback period of two to three years is achievable
  • The type, design and layout of a hotel grey water recycling system depend on the of functions where water is used (washing, cleaning etc) and the waste water content that exists after such functions have been performed. Each system must be customised to suite specific hotel needs
  • Design and layout of the piping in the grey water system will directly affect performance
  • Regulations require that mixed wastewater is discharged to the appropriate drain system (i.e. storm or sanitary drains).  
  • Some Greywater systems may need to add chemicals to kill harmful microorganisms or may need special treatment to remove harmful toxins.
  • In the future, the regional and local government may require permitting and monitoring of grey water systems.
  • Grey water recycling systems also include biological systems (plant systems as treatment ponds, constructed wetlands, living walls, activated sludge systems etc.
  • It is not advisable to include any water containing fat deposits (from staff kitchens or canteens)
  • The diluted residues, soaps etc in the water can provide useful sulphates and nitrates which some experts say is more beneficial to the garden than clean tap water
  • The system requires maintenance and monitoring which includes periodic water quality testing
  • Storage tanks can be below or above ground


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