We use a breathtaking amount of water. On average, every American uses about 300 gallons of water every single day, most of it indoors. Those applications are pretty fundamental, of course—we’re talking about washing our bodies, dishes, clothes, and homes, not to mention cooking, drinking, and heating.
Most of that water is literally wasted down a drain. Water used in bathing, cooking, and other activities is called greywater (sometimes spelled graywater here in the U.S.), and that greywater is estimated to account for about 75% of the water we literally flush into the sewers. While a lot of that water gets treated and returned to the system, it’s still an incredibly wasteful way to manage a precious resource—and since you’re paying for the water that gets pumped into your house, it’s also a waste of your budget. But you can do something about that, because greywater is totally re-usable in different ways, and not that hard to reclaim.
The difference between greywater and blackwater
It’s important to note that the water you flush down your toilet isn’t greywater—it’s blackwater, and isn’t safe to use in any way. And the water that goes down your kitchen sink may be problematic as well, because of the potential for grease content. But everything else in your house? Fair game, as long as you take a few precautions.
Local and state laws on greywater use
Greywater use is regulated in some way in most states, so before you do anything, you should check what kind of laws are in effect in your area (you might also check if your Homeowners Association has greywater-specific rules). Most states actually encourage using greywater, but some have specific guidelines about the type of systems you can set up and the ways you can use the water, and you might need permits.
If you’re about average and using 300 damn gallons of water every day, you should be able to reclaim a significant amount of it for other uses (after all, you paid for it). Even excluding your toilet and kitchen sink, there are plenty of sources of greywater in your house:Washing machines. These are enormous sources of water, and come with one huge benefit: They have built-in pumps that are already moving greywater into your drain system. All you need to do is hook up a diverter valve that will redirect the water someplace more useful. This can be a complicated project or just pumping the water into an outdoor bucket—either way, you’re recycling a valuable resource. One note about greywater from washing machines, though: Its usability depends entirely on what you put in the machine. Washing dirty, poo-riddled diapers means the water in there is blackwater, not grey, and can’t be used. And you should be careful to use biodegradable soaps that are plant-friendly. Showers and sinks. Hot showers are mankind’s peak achievement, but they’re also inherently inefficient. Reclaiming that greywater is as simple as bringing a 5-gallon bucket into the shower with you to capture that water instead of letting it run down the drain. Once collected, it can be used any way you see fit. Similarly, instead of letting water run down the sink drain when you’re washing up, use a smaller bucket to collect water there. Miscellaneous water. Anything in your home that uses, collects, or builds up water can be a source of greywater: air conditioning units that need to be drained, old fish tank water, water leftover from cooking, and so on.
Ways to use greywater
As long as you’re careful to use biodegradable soaps and other products, the greywater you collect has a wide range of uses:Irrigation. Whether watering your lawn or keeping your garden lush, there’s no reason you can’t use greywater to irrigate your landscaping. This can be as simple as carrying a bucket to the yard and filling your watering cans with it, or setting up a more ambitious laundry-to-garden irrigation system. Toilet flush. Got a bucket of water after your shower? Dump it into your toilet for the next flush. There’s no reason you need to use clean, potable water to flush a toilet. In fact, for about $100 you can install a toilet tank sink that will let you refill your toilet tank every time you wash your hands or brush your teeth—no bucket required.
One final note of caution: Don’t try to store greywater. Because it’s been used to wash stuff, it’s not exactly clean, and if left standing it will become a source of bacteria and other dangerous stuff. Greywater is perfectly safe at the point of collection and should be used pretty much immediately.
If you think about it, flushing so much water down the drain without even the slightest effort to repurpose it is kind of wild. Fortunately, all you need to change the dynamic is a bucket.