Greywater system buyers guide


Water restrictions require creative solutions to keep gardens alive. Adam Maxey looks at the pros and cons of greywater recycling.

The advantage of greywater is that we produce it on a daily basis. In most cases it can be intercepted and diverted to the garden with minimal effort and cost in a number of different ways. However, whether you intend to buy a commercial greywater system or set-up your own DIY system there are a number of things you need to consider. This guide highlights the main issues associated with greywater reuse. There are many choices available and there is no single solution for all circumstances. Therefore, the more research you do, the more suitable your system will be for your particular situation.

Greywater sources

Greywater is any wastewater generated from your laundry, bathroom and kitchen, before it has come into contact with the sewer. This includes bathroom (bath, shower and basin), laundry, kitchen and appliance discharge. It does not include toilet wastewater, which is classed as blackwater.

However, while kitchen and dishwasher water is technically greywater, unless you are treating kitchen greywater it is recommended that this source of water not be used. Kitchen water only makes up around five percent of total water consumed in the average home, yet it is considered the most contaminated. This is largely due to high sodium levels from dishwashing detergents, particularly from dishwashers, as well as fats, grease and oils from cooking and cleaning, which can all damage soil structure if allowed to build up.

Cleaning products

Choosing the right cleaning products is perhaps one of the most important elements in reducing the risks associated with greywater reuse. The chemical and physical quality of greywater varies enormously, as greywater is essentially made up of the elements that you put into it.

Generally speaking pathogen and bacteria content is low in most greywater sources (unless you are washing contaminated items such as nappies, soiled clothes etc) and as long as you take all the right steps to minimise potential contact, such as delivering greywater subsurface, it is of minimal concern.

Equally, phosphorus and nitrogen are nutrients necessary for plant growth. If phosphorus and nitrogen are kept to an optimum level by choosing cleaning products with low phosphorus and nitrogen, they can replace the need for fertilisers for gardens and lawns, and the nutrients can actually be utilised by plants and soils.

Read the full article in ReNew 102

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