If your home could save you money every month, reduce the strain on your city's water supply and sewage treatment and help save the environment - wouldn't you want it to? It can, if you incorporate grey-water recycling into your renovation or new home building plans.
What is grey-water?
Grey-water is used water that comes from sinks and drains, as well as reclaimed rainwater, that has been treated and filtered. It is reused to flush toilets and water lawns and do laundry. It is non-potable - not for drinking - or for showering or bathing.
There are different types of grey-water, the difference being the original source of the water and what it was used for. Light grey-water comes from bathroom sinks, tubs, showers, laundry and can include rainwater.
Dark grey-water will include water from kitchen sinks and dishwashers. It contains food waste, grease and bacteria, as well as possible chemicals from household cleaners. There's also black water - water that has come in contact with toilet wastes. Black water has to be chemically treated and disinfected before it can be reused.
In every standard house's plumbing, all wastewater is combined at the main sewer, and all grey and black water is drained away together. Many local building codes consider any and all water that has exited any plumbing fixture to be black water and require it to be sent through the municipal water treatment system.
But not all wastewater is the same. And maybe some of it can be diverted and filtered for alternate uses.
Is it against code?
Recycling grey-water is still not legal in many North American municipalities and it's not a part of most municipal building codes. There aren't provincial or federal governmental guidelines for using grey-water systems. Each individual municipality accepts or rejects proposed grey-water systems that homeowners might want to install. But it can be done, and is being done, in many cities across North America.
You and your builder or contractor will have to work with your local building authority and plumbing inspector if you are interested in going the grey-water route. You'll need a special permit and inspection.
And, you'll need to install dual plumbing, to make sure there are separate lines running to keep the potable and non-potable water apart.
How is it filtered?
Different grey-waters need different treatment processes to make sure they are safe, for people and for the environment. Even though the final use for grey-water is not as potable water, it still needs to be treated. Don't forget, it may just be used to flush toilets in the house, but pets could drink the toilet water. And, if you used untreated grey-water directly for irrigation it could affect the garden's health and the local water table.
The grey-water is diverted into a holding tank, where it is filtered and treated before being sent back into the house for re-use. On a recent project, we buried the cistern under the front lawn. The cistern is made of concrete. It's very strong and stable, it's water-tight and lasts a long time. Plastic is another option.
On that project, we only use reclaimed rainwater, collected from the house's roofs, for flushing toilets, exterior irrigation and for laundry. The system is energy-efficient and greatly reduces the impact on the city's water system, especially during dry summer months. Not to mention it can greatly reduce the monthly water bill.
Save the environment
According to Environment Canada, toilets use one-third of a household's total water consumption. That's 33 per cent of your water bill, and it adds up to a lot of money. Only around 10 per cent of the clean water from your tap is used for drinking or cooking. The rest gets used for showers, baths, laundry and everything else.
A grey-water system in a house, used to flush toilets and water lawns, could save about 150 litres of drinking water per day, per household. Don't forget, that also saves that same amount of water from being sent out to the sewer system and reduces the strain on municipal sewer systems and treatment plants.
Recycling water and using grey-water is sustainable, environmentally friendly and saves you money. I think it makes sense.
Mike Holmes is the host of Holmes on Homes on HGTV. E-mail Mike at mikeholmes@holmesonhomes.com or go to www.holmesonhomes.com