Recycling greywater for gardening

Greywater is wastewater from any household source other than toilets. Greywater makes up roughly 60% of household wastewater. A greywater recycling system uses water primarily from showers and bathtubs. It can also capture water from bathroom or wastewater from the utility sink and washing machine.
Wastewater that includes toilet waste is called black water. Because it contains fecal matter, black water is not safe for domestic recycling under any circumstances.

Some advantages of recycling greywater
  • Useful during periods of droughts or water shortage
  • Saves on your water bills
  • No wastage of water
  • Helps save useful plants and vegetables when the water supply is very low
  • Can be used for collecting and using rainwater

Create your own greywater recycling system

The simplest and cheapest greywater recycling system is to capture shower and bath water in a bucket and use it to flush a toilet. But take care never to fill the flush storage tank with greywater as it will start smelling and may clog the flushing mechanism. Another simple way is to collect the water from a washing machine in a tub by connecting the outlet to the tub, and using this water for the garden.

There are other, more expensive systems in the market. But with simple tools you can also create a recycling system at home or make a small model of it to display at the science fair or exhibition at school.

You will need a filter to collect any waste materials, 2 big buckets, drainage pipes, valves to control the flow of the water, a surge tank and a lever to control from which source the water is coming. You will also need a small garden in a wooden box. Make sure the plants you select are not vegetables or fruit plants. For the model you need not use a pump. Just make sure the source of greywater is higher than the drainpipes. Attach the filter or home made sieve to the top of one bucket.

Pour clean water in one bucket and greywater in the bucket with the sieve. Both buckets must be connected to the drainage system. But when water from one bucket flows through it the other must close. The valves will do this. When the bucket with greywater is full, open the valve to let the water flow through the drainpipe. Make sure the water does not collect at one place as it will then be a breeding ground for mosquitoes and also cause flooding. It should flow steadily on to the soil in the small garden.

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