It becomes so very dry in Lara that our strong Kikuyu front lawn just shriveled up during summer and turned into a dust desert where only a few hardy weeds survive in the cracked up dry clay. With our house slightly raised on stilts, I thought it would be relatively easy to do the “grey water project”.
Collecting grey water
The first step is obviously to collect the grey water. Even though the bath and shower outlets are relatively easy to get to, that is, if you don’t mind crawling through the dust and spider webs under the house, the rules and regulations around plumbing and electricity are so stringent in Australia, that I got a plumber to do the connections for us. So to cut a long story short, two bathrooms and the laundry were all connected under the house, led out to a Matala grey water filter and pump combination, from where it is pumped into a 1000l holding tank, which by regulation must be flushed every 24 hours. The Matala filter and pump, obtained from Clearwater Lakes and Ponds, is quite a nifty little box, with filters, pump, timer, overflow and all parts and connections inside a neat little box.
Distributing grey water
OK, now for the easy part, I thought. Connect a pump and a few irrigation pipes to the 1000l holding tank, and Bob’s your uncle, right? Once again I was hit by the rules and regulations. In Australia grey water has to be distributed in special purple pipes, it may not be sprayed above ground at all (to avoid little children playing close by getting any infections, I was told) and a few other regulations which I cannot remember at this stage.
So my quick and cheap project turned into a serious endeavour, where I needed a very powerful pump to distribute the grey water under the ground, through to the pressurised “purple pipes” that had to be laid under the lawn. Yes, under the existing lawn. Many calculations later about how many meters of pipe can be supported by how strong a pump, and many dollars later I was ready with a strong pump, many meters of purple pipe and a gazillion little fittings, valves, pressure equalisers and who knows what else. I must add I was assisted very well by Total Eden in Geelong, who know their water-stuff thoroughly. You don’t get that level of advice and suitable products from your local hardware warehouse. For one, their 13mm clamps are about double as thick and strong as you can get anywhere else.
Everything except a distributor – an automatic multi-zone valve, to be precise.
With all the calculations – again performed very thoroughly by Total Eden – it came out that we needed two separate sectors under the lawn, and I wanted a third one to water a wild bit of natural growth on the “hill” – an area raised about 2 feet, at the back of the property (which we later realised was a dump of old building material, with a very thin layer of soil raked over it – so no wonder nothing ever wanted to grow there.) So, the challenge was to find a 3-way automatic distributor out there. Eventually I found a 4-way valve online, which distributes 100l down each outlet pipe, in rotation. I couldn’t wait to install it. However, what they don’t tell you on-line, nor in the “manual” about this particular product is that the outlet pipes are so close together, you cannot really get a wrench in there to fit the third and fourth outlet pipes, especially if you’re working half-upside down in a very limited space. (OK, with a one acre property, why I had to wedge the valve in between the irrigation system and one of the tanks, no-one knows. But it was out of sight, and needed minimal distance plumbing…)
The other thing they don’t tell you is under what pressure the product works, or fails, in this case. After about a year, the valve started leaking all over, creaking under the strain of the water pressure. Luckily the local irrigation shop had a high pressure replacement at the time, which flushes an entire load (approx. 1000l in our case) down each outlet in rotation order. All or nothing, but that worked well for us – a good soaking was better than a quick squirt.
Now the only remaining part of the installation was to lay the pipes under the lawn. I rushed off to Kerr’s Hire, an amazing tool and equipment hire company close by that rents out any equipment you can possibly think of. Signed all the papers and off I went with a man-size trench digger. I didn’t even progress 10 meters with the first little indentation in the ground – when I realised, said man-size trench digger wasn’t going to make the grade. The soil is just too hard. So back to Kerr’s I went and exchanged the trench digger for a serious Vermeer with a trench digging extension.
Now we were humming along nicely, but with the hard soil I still had to make two slow passes for each trench. Except said trench digger fitting only dug the trenches – it didn’t remove the soil from the trenches, or maybe I just didn’t know how to get it to do it? A gazillion shovel loads and a sore back later, I could embark on the laborious job of laying and connecting all the purple pipes.
Another gazillion shovel loads and a sore back later, the pipes were covered, raked sort-of evenly and we were ready to rock and roll with a grey water maintained lawn.
The good news is, the past two summers have been really great with an almost maintenance-free green lawn on which the kids and dogs can run and play throughout the year.
Maintenance-free, that is, if it weren’t for the spiky weeds (mostly burr clover) we get each spring and summer, but I’ll cover that in another post soon.
- Study the local rules and regulations about grey water collection and distribution up-front.
- Buy the products from a distributor that can give you the detailed specifications.
- However, despite the costs and efforts, in today’s world of climate change and overused resources, we need to save and use every little bit we can, including our grey water.