“Why I chose grey water to buying another tank”
Priscilla Van Den Broek
We installed a grey water system because I was sick of emptying the shower water into a bucket and lugging it down stairs to the garden, (splashing all the way.) We chose to use grey water rather than install another tank.
The system we chose does not store the grey water but it disperses it through gravity feed irrigation lines in the garden, via a small tank. The garden beds are zoned by water needs so that you can choose where you would like to water at any given time. Now I know that every time I have a shower, bath, or use the washing machine my garden is benefiting. We selected sub-soil irrigation and it has proved to be the most suitable watering method, allowing the soil and plant to take up the water as required.
Since installing the grey water in September I have saved over 51,000 litres and not used mains water in the garden at all. This equates to saving 140 litres of water per day, compared to the same time in 2007. We are currently using a total of 490 litres of water per day for a family of five.
We have a large garden of 1200 square metres full with fruit trees, veggies, ornamentals, natives and perennials. As you can see we are using 57 litres of water a day less than the recommend usage per person. The garden has only been planted out over the last 2½ years, so it is still establishing itself. Our water tank is not connected to the house and is only used in the pool and garden.
I feel the tank and grey water go hand in hand, so I can water the pot plants with the tank and water the veggie garden - alternating between grey water one day and a few days later the tank water. This flushes any bacteria from the vegetables, which may have come from grey water. Grey water may contain many micro-organisms or pathogens; including bacteria, viruses, protozoa and fungi. Be careful when recycling grey water. It cannot be stored for more than 24 hours untreated. Bacteria can quickly build up and cause health risks and bad smells.
None of the grey water is directly applied to leaf crops as the water goes into small test tube-looking pipes which are pushed into the ground approximately 5cm below the surface, which is called sub-surface irrigation. It is recommended not to use this system with root crops. Although personally I have not had any problems yet, although it is early days.
I am using only the grey water on the rest of the garden and everything is healthy. The only issue that I have had was some of the grevilleas looking like they may have had too much phosphorus. This occurred when we first put the system in. But they are bouncing back, they are getting new growth. So I will keep my fingers crossed. Perhaps they needed some time to adjust to the different water?
I think the key to recycled water is not to use it in the one spot and not over the foliage of plants. Spread the use over the whole garden a different area each day or two.
We use organic shampoo and conditioner in the shower which has low sodium (0.2%). In the laundry I am using a low phosphorus laundry liquid in a front loader machine. The most suitable laundry products for grey water use on your garden are liquid detergents that have low sodium level, phosphate free and are pH neutral such as Greencare liquid which is available at most supermarkets. If at any time I need to use something a little stronger for heavily soiled washing I can switch the washing to send the water down the drain. Some washing powders may contain up to 80% fillers. Fillers are extremely high in sodium and phosphorous. Both are harmful to our environment and natural waterways. Liquid detergents have less sodium because they normally don’t have fillers as bulking agents.
The grey water system is very easy to maintain. You only need to empty the filter weekly and rinse the irrigation lines every 6 months with a flush of clean water.
The cost of the Greywater Gardener 230, was $5000 complete. That included the installation and all the irrigation pipes, plumbing etc. And we received a $500 credit on our water bill from South East Water. This made it a total of $4500.00. This was very similar to what we spent on the 22,000 litre tank. After we had excavation done, built the foundation for the tank and then the plumbing, the tank cost was about $4500 as well.
So if I had to choose a tank or grey water? I would choose the grey water as you have a constant supply of recycled water and you don’t have to rely on rainfall. Especially if you are in a suburban block and don’t have space for a water tank. The grey water along with the 2 days a week stage 3a allocation of water would be enough for most people to have a beautiful productive garden.
We bought our system from Waterwise Systems Ph: 1300 133 354