Grey Can be Good: Water that Is
Posted by Lisa Carey
“Gray hairs” don’t always make us smile and “grey areas” sometimes get us in trouble. But it’s really clear that reusing grey water is a good thing. It’s economical for homeowners and eco-friendly for the environment.
What is grey water?
Grey water is the reusable water from showers, tubs or washing machines. Water from sinks, dishwashers or toilets is not considered to be grey water.
Grey water can be diverted outside and reused to water plants, shrubs, trees or lawns. With the addition of a holding tank, grey water can also be used to flush toilets.
How much grey water does a typical home generate?
A recent study revealed the percentages of water used in homes for various purposes-
20% for laundry
10% for kitchen and drinking needs
5% for cleaning
35% for showers or baths
30% for toilets
That means that over half of the water used in homes is used for laundry or showering and bathing and therefore is grey water.
Advantages of using Grey Water:
*Can reduce ground water usage by up to one-third
*Helps septic systems as septic systems work best when a lot of water does not enter at once
*Reduced water bills
*Reduced electric bills
Some newer homes, especially those labeled as Sustainable Development or Green Built, are already plumbed for grey water diversion. The grey water pipe is connected to the sanitary drainage system and a three-way diversion valve must be installed on the line. These valves are available from plumbing or pool supply stores.
Grey water can either be drained directly to the landscape or can be drained to and stored in a tank. If it is being drained to the landscaping adding straw, bark or organic materials to the soil can improve filtration and create a more porous surface. If it is stored, plumbing codes will apply to how long the grey water can be stored before use and generally this is a couple of days.
Grey water systems, such as The Brac Systems, can be designed into new construction or added to existing residences. With a water recycling system, drains from the showers, tubs and laundry are routed to the recycling system and filtered. The tanks often use a tri-chlorine tablet similar those used in swimming pools to keep grey water bacteria and odor free.
Credits for Grey Water Systems
Many states offer homeowners or builders credits for installing a grey water system. For example, in Arizona a homeowner who installs a grey water system can receive a credit of up to $1,000.00 and homebuilders can receive up to $200.00 per grey water system installed.
Special Care when Using Grey Water
When using grey water, you need to be especially careful about what goes into your water supply.
Water softeners- Only use a potassium salt and not sodium to soften water. Sodium chloride salt will burn plant leaves. The potassium chloride will not but it is more expensive.
Laundry detergents- Use only laundry soaps that do not contain boron and are low in sodium.
Cleaning products- Use phosphate-free or low-phosphate household cleaners and natural detergents. Need more information on making your own cleaning products? Read, Recipes for Whole House Cleaning Success: Natural and Environmentally Friendly
More and more communities are recognizing that water is a precious resource and that consumers need to not only reduce their use of water but also reuse and recycle grey water. Reducing lawns and using rain barrels have been two effective options for good water stewardship. Using grey water recycling systems has proven to another effective green option. Today many communities are encouraging the use of grey water systems and in the future it is expected that many communities will take an even stronger stance and mandate the use of grey water recycling systems in new homes.
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It is not a good idea to store gray water over 24 hours. after that time it becomes black water and smells like a swamp. I have a 125 gallon tank that my washing macnine pumps the water into. IT then has a gravity feed hose to the plants. If i do not use the water within a day it becomes very nasty, swampy and smells like sulpher. I have not done any testing on the black water but I would assume it is toxic