As water scarcity becomes more prevalent, people are turning to different ways of conserving and reusing available water. A greywater system is one such effort at recycling, but there’s still a lot of confusion and misconceptions among the public, as well as the policy makers, about the safety and efficacy of this method.
What is greywater?
Water that has been used for various purposes in the house such as cleaning, washing and bathing comes under the label “greywater,” while that which is flushed out of the toilets is called “blackwater.” Since our traditional sewage system is not designed to make a distinction between the two, all the used water is drained out into the same sewage line. But the greywater produced in a household actually does not require the same treatment as the sewage when it is used for non-potable purposes like watering the garden and flushing the toilet.
How does it benefit you to reuse greywater?
1. Greywater reuse lowers your water bill. About 20 gallons are used per wash in a front-loading type of washing machine, and double that amount in a vertical axis top-loader. Think of all the water that is pumped out of washing machines every day, and how much you can save by reusing it. If you include the water from the shower, too, it will add to your savings.
2. It reduces your power needs. Reusing water lowers energy expenditure in many ways. A gravity-based greywater system does not require additional power while it waters the landscape. The total amount of water used by the household comes down, which translates to power savings.
3. It can help extend the life of the septic system. Greywater constitutes the lion’s share of sewage dispelled from a home. Diverting a large portion of it from the septic systems will reduce the load on them and keep them working longer and more efficiently.
It is paradoxical that government policies in many states still disallow greywater usage when less water to pump into the households and less sewage to be treated by sewage treatment plants means significant water and power savings all around. Safety concerns may be behind this, but drier states like Arizona, California and Texas that have liberalized their greywater policies have not reported any untoward incidents resulting from it.
Not surprisingly, more and more people are installing greywater systems for personal use, whether it is legal in their state or not. However, it is advisable to check out the local policies before you plan to invest in greywater recycling.
What are the different greywater systems available?
Laundry drum system.
This simplest of the greywater systems is the cheapest, too. It runs exclusively on the greywater released from the washing machine and requires no extra power other than the normal pumping done by your machine. The water is collected in a large drum that acts as a surge tank. The outlet from the drum is at the bottom, and it is connected to a hose pipe that can be used for watering the plants by just moving it.
Laundry to landscape system.
This is another simple landscape-direct arrangement that diverts the water from the laundry to the yard to irrigate the trees in the garden. A valve diverts the water to a hose that carries it to a mulch basin dug around the trees. You can install this system yourself for as little as $75, but enlisting the help of a professional may cost you more.
Branched drain system.
If you want to include water from the showers, and also water a number of plants, a branched drain system facilitates it. Greywater from the kitchen sink is often excluded because it contains high amounts of grease and salts.
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Water is collected from different points in the house and then distributed to many mulch basins by splitting into several branches. Since it works on gravity, its 1 ½ inch drain pipes should slope down at the rate of one-fourth inch per foot to maintain the flow to the mulch basins. It is more complicated to install, and even impossible in some cases if the existing drain pipes are buried under the house.
Filtered drip irrigation system.
Since the greywater may contain solid particles that can clog the drip irrigation system, it has to first pass through an effluent filter. While it can provide a more efficient distribution of water, the system is high on maintenance as the filter and the drip nozzles need frequent cleaning.
Here, a constructed wetland acts as a filter, cleaning up the greywater while nourishing the water plants with the nutrients it contains. This is more of an environment-friendly arrangement for the disposal of excess greywater.
It also protects the nearby waterways from pollution that may result from nutrient run-off.
Pumped greywater system.
Gravity-based systems work only when the water flow is directed downward. If the garden to be irrigated is at a higher level than the house, the water has to be pumped uphill by an external pump. The drawback is that it involves additional energy expenditure in addition to the higher initial cost.
What is the greywater system of choice?
While the system you choose should be tailored to your specific needs, you should consider cost, ease of maintenance and local restrictions before installing one. For example, some states allow only laundry water to be reused. As a rule, the more complex the system is, the more costly its establishment and maintenance. It is always better to go in for the simplest one that would meet your requirements.
Safe use of greywater
While many people, including policy makers, are not convinced about the safety of greywater usage, it is by and far considered harmless if certain precautions are followed:
1. Do not handle greywater. It is contaminated to some extent by bacteria and certain chemicals that may irritate your skin.
2. Do not store it. Greywater should be allowed to drain off straightaway. Storing it overnight may cause it to stink.
3. Use it for irrigation purposes in your garden only. Greywater can be safely used in the garden even to grow food crops as long as the edible parts do not come in contact with it. Do not spray it or use it on root vegetables.
4. Keep it from getting pooled up in the garden. If allowed to stagnate in the garden, greywater can become a breeding ground for mosquitoes and turn into a health hazard.
5. Do not allow it to run off your property. Restrict the use of greywater to your own garden. Dig up sufficiently large mulch basins to protect against effluent overflow.
6. Use organic cleaners and sodium-free soaps and detergents only. Sodium and many other chemicals present in the detergents can be toxic to the plants. Use potassium-based water softeners if necessary.
Have you used greywater? What tips do you have? Share them in the comments section below: