If you’re building a new home, installing a rainwater tank can help you achieve the minimum regulatory requirements of the 5 Star Standard. To meet the 5 Star Standard with a rainwater tank, the capacity must be a minimum or 2,000 liters with a minimum roof catchment area of 50 square meters.

Rainwater can be used flushing your toilet, watering your garden or for use in washing machines. You should test rainwater for portability (drinking quality) before you considering drinking it.

Why use rainwater?

The best reason for using rainwater is that it is free and, if not captured in a tank, it is a vital resource that literally goes down the drain.  Rainwater tanks are an increasingly common feature in gardens around Australia. Despite the initial cost, installing a rainwater tank can save you money by reducing your water bill in the long-term, and help save the environment.

If you’re building a new home, installing a 2000 liter or more rainwater tank for toilet flushing is one of the options to achieve the minimum regulatory requirements of the 5 Star Standard. The Victorian Government offers rebates of $150 on the purchase of rainwater tanks (600 liter minimum) that are installed by a licensed plumbing practitioner.

Greywater is the name given to wastewater from household appliances such as showers, baths, basins, sinks, washing machines and dishwashers. It does not include wastewater from toilets (this is known as black water).

Using greywater can carry a number of potential health and environmental risks. Care must be taken to ensure that greywater is used in a safe and controlled manner. Using greywater correctly can help you conserve water.

How can I use greywater?

Household greywater can be used to water your garden and/or for toilet flushing. Using treated greywater for toilet flushing can potentially reduce your domestic water consumption by up to 20 per cent. However, untreated greywater is not suitable for toilet flushing.

A trial on greywater use for toilet flushing and garden irrigation, carried out on four houses in Melbourne by Victoria University, resulted in water savings of tens of thousands of liters per year, for each household.

Am I allowed to use greywater?

To find out if you are allowed to use greywater, and for qualified professional advice, contact authorities, such as your local council, or the Environment Protection Authority.

In most cases, untreated greywater can be diverted for immediate use, as long as there is no adverse impact on public health or the environment.

Risks of greywater

Greywater contains many pollutants, such as chemicals derived from cleaning products, dirt, food and human waste. The bacteria and chemicals from these pollutants can affect the health of your family and your garden. The health and environmental risks of greywater can never be eliminated, but they can be minimised by careful management and responsible use.

To minimise the health and environmental risks when using greywater:

• Ensure greywater does not contaminate any drinking water sources
• Ensure adults, children and pets cannot drink or access the greywater
• Greywater use must be confined to within your property
• Greywater must not leak into storm water drains or waterways
• Untreated greywater must not be stored longer than 24 hours
• Overflow from a greywater system must discharge to a sewer or septic tank
• Do not use greywater to water vegetable crops that are eaten raw or undercooked
• Do not use greywater that could have human waste contamination, e.g. water used to launder nappies
• Use low risk sources of greywater, such as water from the bath, shower or laundry rinse water
• It is not advisable to use laundry wastewater, due to high detergent concentrations
• Kitchen wastewater should not be used as it is heavily contaminated with fats, greases and solids
• Apply greywater to the garden using a below ground system such as drip irrigation as this will reduce human exposure
• Always wash your hands after gardening
• Use low-phosphorous detergents (visit www.lanfaxlabs.com.au for information on detergents)
• Carefully monitor the impact of the greywater irrigation system on your garden.

• Check for leaks – leaking taps, pipes or dishwasher hoses can waste more than 2,000 liters of water per month. Checking for leaks is a cheap and easy way to save water. Replace washers regularly to avoid leaks.
• Install water efficient tap ware - water efficient taps and showerheads can save up to $100 a year in water and energy costs. Combining water efficient tap ware with aerators and flow restrictors can help reduce water use by 50 per cent compared with standard tap ware.
• Turn off taps - Leaving taps running when not in use can waste up to 17 liters per minute. Ensure you turn off taps when brushing teeth, washing vegetables or cleaning.
• Short showers - taking shorter showers can save hundreds of liters of water each year.
• Install a dual flush toilet – dual flush toilets are water efficient and use up to 60 per cent less water than single flush toilets.
• Install water efficient appliances - appliances such as dishwashers and washing machines can often use a large amount of water. When purchasing water-using appliances, ensure you choose a product that has a high water efficiency rating, such as a AAA rating. Ensuring you always have a full load before washing can also reduce water use.
• Recycle water - you can reuse some of your household wastewater, known as greywater, to use for watering your garden or for toilet flushing. Restrictions do apply to greywater.

Saving water in the garden

With water restrictions in place across Australia designing a garden that is water wise can help you enjoy your garden during tough conditions:

• Select water efficient plants - most nurseries now offer a wide range of low water-use plants and shrubs designed to endure drought conditions. Water efficient plants will reduce the amount of water your garden needs and can look good all year round. The Department of Sustainability and Environment publishes a list of drought tolerant plants
• Mulch your garden – using organic mulch, like cow/chicken manure or compost, can improve the quality and water retention of your soil. Mulched garden beds retain more water and require water less often. Look out for new products that can assist your soil to retain water.
• Soak – giving your plants a good soak once a week or less will help them develop their root systems more effectively than a light, regular spray. Healthy plants are more likely to survive tough conditions.
• Install a rainwater tank - collecting rainwater can supplement your water sources for the home and garden.
• Use recycled water – Installing a greywater system can provide a great source of water for your garden.
• Weed – regular weeding will stop weeds from competing for water with your plants.
• Watering systems - using a below ground drip irrigation system can deliver water straight to the roots of your plants, where they need it most. Below ground watering systems are important if you are using recycled water to reduce the health risks associated with greywater.

Together we can all do our bit to help reduce water consumption. Installing water saving products can make a difference and despite the initial cost, they are an investment. In the long term, you will be saving money and helping the environment. There are many water saving initiatives, as well as great products that can help conserve water.

If you are planning to install water saving devices, always ensure you use a licensed plumber for any plumbing installations. To find your local licensed plumber check out http://laserplumbing.com.au/your-local-plumber/.

http://www.savewater.com.au/how-to-save-water/in-the-home