Greywater Recycling and Re-use
What is Greywater?
Greywater is wastewater generated from domestic activities such as laundry, dishwashing, and bathing, which can be recycled on-site for uses such as landscape irrigation and constructed wetlands. Greywater differs from water from the toilets which is designated sewage or blackwater to indicate it contains human waste. Greywater is of lesser quality than the water directly from your faucet, but of higher quality than blackwater, hence the appropriateness of the term greywater. In the average household, approximately 50-80% of residential wastewater is greywater that can be effectively reused for other purposes, such as watering the landscape.
Why Use Greywater?
It's a waste to water plants and grass with drinking water when plants will actually thrive on used water containing small bits of compost. We can make greywater recycling a part of the fundamental solution to many ecological problems. The benefits of greywater recycling include:
- Lower fresh water use.
- Reduces strain onseptic tanks and treatment plants.
- Highly effective purification.
- Less energy and chemical use.
- Groundwater recharge.
- Improved plant growth.
- Reclamation of otherwise wasted nutrients.
Is Greywater Recycling Right For You?
Before you start a greywater recycling program in your home, be sure you have taken all possible measures to conserve water first. Have you utilized:
- Low Flow Showerheads
- Low Flush/Composting Toilets
- Aerators On All Faucets
- Efficient Front Loading Washing Machine
- Natural Landscape Using Plants Indigenious to Your Region
- Rainwater Harvesting
If you can say "Yes" to all the above bullets, then you can start to think about greywater recycling. Now before you go "gang-busters" on this new endevour, it is very important you have clear cut goals in mind and you are aware of local and state regulations on greywater recycling. Also, are you willing to make the commitment to a total lifestyle change that is required of this type of water conservation. Having gone through all these elements in your mind and with your family, if you are still eager to start this project, let's talk about how to design a recycling systems that meets your needs and can work with your surroundings.
How To Design a Greywater System For Your Home
The first step is to assess the potential amount of greywater your home and appliances might generate. The appliance-water use listing below can help you estimate usage in gallons.
- Top Loading Washing Machine: 30 gallons per cycle
- Front-Loading Washing Machine: 10 gallons per cycle
- Bathroom Sink Wsage: 1 - 5 gallons average use
- Dishwasher: 3 - 5 gallons per cycle
- Low-Flow Showerhead: 3 - 7 gallons per shower average
Next, use the data regarding the site and your design considerations to determine what steps are relevant for your situation. Give special consideration to the final dispersion of the effluent, making sure that the soil can accept the amount of water that will be generated, treated and discharged (your local sanitation engineer can do a percolation test to determine the ability of the ground to accept water). If water shortage happens to be a particular restriction where you're located, note that greywater filtered through a soilbed of this sort will not become anaerobic and thus can be saved for lawn irrigation.
Lastly, check with local authorities regarding regulations regarding greywater system usage or placement. Submit your application to the local board of health or consult your local professional engineer (P.E.) for plans and documents needed for your application (usually a topo-graphic site drawing with pertinent information about your site and the proposed solution).