You may not realize it, but greywater is one of your household’s most valuable resources. However, in most homes it’s sent into the sewage system where it immediately becomes useless—even dangerous—for both humans and the environment. From there, it undergoes expensive and energy-intensive treatment at a sewage plant. That’s unfortunate as Americans use 80 to 100 gallons of fresh water per person each day, or nearly 4,000 gallons per person every year - much of which becomes greywater.
Fortunately, you can solve the problem by recycling greywater for your own needs. Doing so saves money and waste, especially when you use greywater for irrigation.
What Is a Greywater System?
Greywater is any water that’s been used in your home without coming into contact with human waste. Showers, laundry machines and bathroom sinks are typical sources of greywater. Water from a kitchen sink often contains high levels of food and other organic matter, so its runoff is often labeled “dark greywater” or even “blackwater” by many local regulations, though it’s considered appropriate for greywater systems by many experts.
Because it’s filled with biomaterials and certain plant-safe household chemicals, greywater can be a fantastic source of fertilizer for plants. While those nutrients would harm the environment (and technically become pollution) if released directly into an ecosystem, they’re a feast for your landscape plants.
How Does a Greywater System Work?
A greywater system is broken down into three main stages: collection, storage and use. At its simplest, you can set up a greywater system by saving your bathwater in buckets and then using it to water your plants. Similar principles work for rudimentary greywater systems that divert laundry machine runoff into a barrel, where it’s stored temporarily before exiting via a hose or bucket into the backyard.
However, nobody expects you to get excited about a lifetime of hauling water buckets around, so most greywater systems rely on simple, tried-and-true plumbing technology to keep everything running safely, smoothly and automatically.
Using a Greywater System for Irrigation
One of the easiest ways to recycle your greywater is to use it for irrigation. Even better, setting up greywater irrigation is relatively simple, and should require very little maintenance if it’s done correctly.
One of the most common types of greywater irrigation systems uses a three-way valve to connect your laundry machine to existing irrigation pipes. Simply turn the valve to send your greywater into the irrigation system, then turn it back to send greywater into the sewer system when it’s not required. This type of system is an especially good fit for our smart sprinkler controllers, since they help ensure you're being as efficient as you can be with your water. Runoff from all the greywater sources in your house can also be added into the system with a bit of additional plumbing.
If you’re planning a greywater irrigation system, there are three points to keep in mind:
Plant suitability: Greywater is typically alkaline, so it’s not always a good fit for plants that prefer acidic conditions, like lily of the valleys or pine shrubs. Additionally, greywater may not provide all of the nutrients present in your local soils, so some plant species will require supplemental fertilizers.
Water management: Greywater should never be stored for more than 24 hours to avoid nutrient decomposition and bacterial overgrowth. Accordingly, you’ll need to find a solution for those times when you produce more greywater than you require for irrigation. Fortunately, a smart sprinkler controller can handle the excess for you.
Water usage: To keep your family and landscape plants safe, greywater should never contain human waste (including runoff from rinsing diapers), chlorine bleach or harsh detergents to prevent dangerous bacteria and salt levels in the soil.
While there’s no limit to how complicated and high-tech greywater systems can be, a simple three-way valve, a smart sprinkler controller and a bit of plumbing is usually all that’s required to start irrigating with greywater. Once you realize you’ll save money and conserve water while reducing your environmental footprint, the math does itself!
Want to learn more? Visit our sources below.
Sources:
http://oasisdesign.net/greywater/
http://greywateraction.org/contentabout-greywater-reuse/
http://www.treehugger.com/green-home/how-reuse-grey-water-home-and-yard.html
http://www.doh.wa.gov/CommunityandEnvironment/WastewaterManagement/GreywaterReuse/PlantIrrigation
http://water.usgs.gov/edu/qa-home-percapita.html
http://www.almanac.com/content/ph-preferences
