Introduction to Grey Water Recycling
Grey water is all the wastewater that is discharged from a house, excluding Blackwater (toilet water). It commonly contains soap, shampoo, toothpaste, food scraps, cooking oils, detergents and hair. Grey water makes up the largest proportion of the total wastewater flow from households in terms of volume. Typically, 50-80% of the household wastewater is grey water.
The main purpose of grey water recycling is to substitute drinking water in applications which do not require drinking water quality. Non-potable reuse applications include irrigation and toilet flushing and dependent on the technologies utilised in the treatment process water can also be used for drinking water again. It is possible to reduce the amounts of fresh water consumption as well as wastewater production, in addition to reducing the water bills. If grey water is regarded as an additional water source, an increased supply for irrigation water can be ensured which will in turn lead to an increase in agricultural productivity.
How does it work?
Grey water are collected from basins, showers, baths and washing machines. The water is treated to be re-use for irrigation, toilet flushing or portable water use.
There are 2 types of grey water treatments – basic and advanced:
- Basic – Pump and drum system with disinfection
- Advanced – Anaerobic, aerobic and disinfection treatment
What are the benefits from installing a grey water recycling system?
- grey water recycling saves water and reduces the amounts of fresh
- grey water is a valuable resource for landscaping and plant growth
- grey water is rich in phosphorous, potassium, and nitrogen, making it a good nutrient or fertilizer source for irrigation
What savings can I expect?
Grey water recycling has the potential to save approximately half of the domestic mains water usage. The resulting financial savings will depend both on the price of water in the area and the amounts of water reused. Municipal water charges are made up of two components namely water and sewer rates, both are charged monthly based on usage from the water meter installed by counsel. 50-80% of the household wastewater can be recycled which will lead to direct saving on your water bills.
What factors can influence my decision?
- Budget:costs for grey water treatment range from simple,relatively inexpensive diverters to complex treatment, storage and irrigation systems which are more costly.
- Existing plumbing:the availability of pipes that carry grey water inside the house will affect the reuse options.
- Existing garden area:somes ystems incorporate surgetanks, which may require space in the garden, and the installation of irrigation systems may disturb existing plants or soil. Garden design and the choice of plants will also determine the watering needs.
- Elevation of garden beds compared with grey water sources:this will partly determine whether or not the force of gravity alone is enough to push the grey water through the system to where it is needed. Some sloping blocks are well suited for gravity-fed grey water diversion systems, while systems that recycle grey water for toilet flushing or flat blocks with raised garden beds may require a pump.