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Homes in Australia can generate up to 400 litres of grey water daily. This is equivalent to around 40 per cent of water use. Putting greywater to further use can, therefore, be very beneficial.
This is also true for Australians in wet and humid areas who use constructed wetlands to soak in excess water. Here, you can learn about greywater systems in Adelaide, how they work, and their benefits.
In addition to the benefits of greywater recycling systems, you can read up on the role of surge or greywater tanks, factors affecting the water's quality, and servicing greywater treatment systems. Read on for more!
What are greywater systems?
Greywater systems are networks of fixtures that help manage wastewater (greywater) from properties. Greywater systems are a great help in treating wastewater. The water is subsequently channelled through a separate network and safely used for various purposes.
Greywater includes wastewater that comes from laundries, washing machines, and bathrooms. Such greywater systems differ from sewerage systems that help drain sewage (blackwater) from properties.
Blackwater comes from toilets and kitchens and tends to have a higher organic loading than other wastewater sources. You can use appropriately treated greywater for toilet flushing, plant irrigation, and laundry. However, note that untreated greywater is generally not ideal for use in washing windows or cars.
Benefits of grey water systems
Using the term "wastewater" for greywater is often considered a misnomer because of the benefits of greywater. You may prefer to refer to it as "Used Water" instead. The reality is that you can improve your water efficiency when you use more recycled water. Here are other benefits of greywater systems.
Added source to existing water supplies
Reusing greywater allows you to reduce tap water usage by as much as 16-45 per cent. Greywater is also a valuable addition to existing water supplies in drought areas.
Saving money and conserving water
Any amount of water reuse can help you save on water bills. Using greywater enables you to save on fresh water and conserve it. This, in turn, helps to reduce your household water bills. Regarding water conservation, you can effectively halve your water consumption by reusing greywater in your garden.
Irrigating gardens
Unlike blackwater, you can reuse greywater in domestic and community gardens. This is because greywater does not contain high levels of bacteria and fats that blackwater has. You can thus find many people diverting greywater from houses for garden irrigation. This is certainly useful when you are experiencing water restrictions and low rainfall.
Reusing and recycling water saves drinking water
Grey water is not suitable for use as drinking water because of the potential to contain harmful bacteria and viruses. However, you can conserve more clean and safe drinking water (that you dedicate for only drinking) when you reuse wastewater. This is because you do not need to use your drinking water in gardens and toilets. This helps to take pressure off valuable drinking water sources.
Improving community water conservation
Undoubtedly, greywater reuse substantially benefits urban water systems since it reduces the demand for fresh water. There is less demand for public water supply. Interestingly, greywater has valuable applications in large-scale cooling towers.
Reducing the amount of wastewater that goes into on-site treatment systems or sewerage systems is also beneficial. The systems have reduced load, and overall community safety is enhanced.
Improving eligibility for rebates
A professionally installed greywater treatment system can save you time and effort. It can also improve your eligibility for a rebate.
Greywater approval requirements
You must meet South Australia's approval process to set up a permanent greywater system. You also need to ensure that you meet regulations that guide the use of greywater systems. You need approvals for every step if you want to set up a system to recycle greywater.
- You can also get advice from your council or state health department on what type of greywater treatment system is accredited for use in your area.
- Talk to SA Health to approve the greywater treatment process and its use.
- Your local government needs to approve the planning and development of greywater systems.
- Talk to SA Health if you need to divert greywater from an existing system. This applies if you are in a sewered area.
- It is also applicable if you are in a Septic Tank Effluent Drainage (STED) scheme-covered area.
- The Department of Health has to approve devices that treat or reuse greywater in South Australia before installation. This helps to ensure sustainable designs, watermark certification, and other standards.
- You should be prepared for fees related to installation approvals and inspections by relevant authorities.
- Confirm whether you must provide a Certificate of Compliance and standard drawings (as constructed) to SA Water within seven days after completing plumbing work. This can apply to SA Water sewer areas.
How greywater systems work
Greywater systems can be of two types: diversion devices and treatment systems.
Greywater diversion devices
Greywater diversion devices work by removing gross solids such as hair or lint through a process of coarse filtration. Such devices divert greywater without treating or storing it. You must ensure that such greywater is diverted to subsurface irrigation systems or other subsurface land disposal systems.
You can use greywater diversion devices to accept greywater from a room or single fixture. However, they cannot accept surge loads. You should, therefore, equip it with an overflow connection to a reticulated wastewater system such as a community wastewater management system.
Your greywater diversion device may not need SA Health product approval requirements. However, do note that you need approval from the local council if you wish to install a land application system for receiving greywater.
Greywater treatment systems
Approved greywater treatment systems are of great use in modifying untreated water and improving the water's quality. Greywater recycling systems often have a treatment process that consists of the following:
- The greywater system begins with wastewater from bathtubs, showers, and washing machines being sent into the system.
- Coarse filtration is used to remove large particles.
- Fine filtration and other multiple-stage filtrations and a biological treatment process follow.
- After that, disinfection of the greywater occurs.
- Ultimately, the filtered greywater is diverted to your gardens and flower beds through drip irrigation hoses instead of travelling through your septic system.
Considerations when using greywater in Adelaide
Some things to keep in mind when using greywater in Adelaide include the following:
Keep recycled water supply separate
Recycled water supply has to be treated at a wastewater treatment plant to make it safe for household use. These uses include flushing toilets and watering gardens. However, the water is not safe for drinking. Therefore, you must always keep recycled water systems separate from rainwater harvesting systems, rainwater tanks, and drinking water systems.
The role of surge tanks or grey water tanks
Grey water that comes from showers and baths can be piped to greywater recycling tanks (also called surge tanks) through greywater hoses. These greywater tanks can store greywater for a short duration before it is discharged to treatment or irrigation systems. You should note that these tanks are meant to hold the water only in the short term. Grey water should not sit for an extended time in grey water tanks.
Factors affecting the water's quality
The type of greywater can affect the quality of greywater irrigation. You may not expect the quality of wastewater that comes from washing machines to be the same as that coming from bathwater.
The type of chemicals in greywater also affects the water's quality. For example, you may have soaps or washing powders in the water. Other factors affecting the quality and performance of irrigation greywater include the irrigation method, watering duration, and whether soil organic matter is present.
Phosphorus level
You must be mindful of the type of greywater that you use for home or community gardens. Some common Australian native plants may be sensitive to phosphorus, and high levels of it can be detrimental to their health. Therefore, grey water for such irrigation should contain detergents with little or no phosphorus.
PH and Alkalinity levels
Repeated application of detergents for greywater can significantly alter soil pH. Laundry detergents can also contain "surfactants" and make laundry water quite alkaline. Both factors can affect soil structure, pH, and plant growth. You may add white vinegar to your greywater before application to the soil if the greywater is too alkaline.
Servicing greywater treatment systems
Remember to follow the manufacturer's instructions for servicing greywater treatment systems. Of course, you must keep copies of service reports according to service agreements the same way you keep your business annual reports.
Using licensed plumbers
South Australia's plumbing requirements (AS/NZS 3500) specify getting a licensed plumber to install greywater systems. Here are some services that licensed plumbers can help you with.
- They can help you install a recommended treated greywater treatment system that permanently recycles greywater.
- A licensed plumber can help provide a regular health and safety audit of your recycled water supplies and drinking water supplies. This will help avoid potential health risks that may arise.
- You can invite a licensed plumber if you have issues with the purple pipes that supply recycled water or water metering issues. They can provide grease trap solutions.
Plumbing contractors provide greywater services
This guide on greywater systems in Adelaide: how they work, and benefits have also considered things to remember regarding greywater systems in Adelaide. One such thing is to use a licensed plumbing contractor. This will help you ensure that your greywater system meets regulatory guidelines and also help you maximise the benefits of greywater reuse.
