Greywater. It’s not sewage, but we send gallons of it into our sewers daily. It’s the water we wash our hands with, shower with, bathe in. We can reduce the amount we create but we can’t eliminate it entirely. We’ve got to get clean.
But we don’t have to send it into our sewers. It’s not sewage.
I’ve been doing the most low-tech of greywater recycling for years – dumping my dishwater out the door instead of down the drain – but when we bought ourselves a piece of land and started thinking about building on it, I started thinking about a more elaborate greywater system.
A little bit of research brough me to Art Ludwig’s Create an Oasis with Greywater, the definitive resource on greywater systems. Art describes the value of greywater, helps readers set goals for their greywater system, and helps them design a greywater system that fits their context. It’s a great (if not very pretty) book.
It also made clear that a greywater system is not for us.
Really? You might be asking. How’s it a great book if it convinced you to not go with a greywater system?
That’s the thing. Ludwig (unlike a lot of so-called green gurus) is an environmentalist with his head screwed on straight. He’s not interested in designing or implementing something that seems green but really doesn’t do any good. He spends quite a bit of time helping his readers to scale down their expectations of a greywater system and to evaluate what sort of system makes environmental and economical (he makes the excellent suggestion that economics can be a proxy for environmental soundness, which I wholeheartedly agree with) sense given their individual context.
In our case, our soil demands that we put an advanced septic system on our land. All our wastewater (greywater and the “black” water from our toilets and kitchen sink) will be sent through a dual-chambered system where aerobic fermentation will purify it before it is pumped through a series of tubing to irrigate our lawn from below. So we’ll already be getting one of the primary advantages of a greywater system (without installing separate pipes) – we’ll be irrigating with our water instead of sending it into a sewer. Furthermore, since the “irrigation” step is an important part of the septic process, we cannot add extra irrigation on top of the irrigation field (which will cover most of the area close enough to the house to be feasibly irrigated with greywater). In addition, a septic system requires a certain amount of “dilution” water to work – so it is possible to remove too much water from the septic through a greywater system.
So a greywater system isn’t for us.
Does that mean I won’t be using anything I learned from this book?
Actually, no. Ludwig points out that there are some forms of greywater reuse that can be done without a fancy system. Using your bathwater and a bucket to flush the toilet? Go for it (I fill our low-flow toilet with bathwater to rinse Tirzah Mae’s diapers in – and then flush it with more bathwater.) And throwing my dishwater out the door after I’m done with it? Well, that’s a tricky one. Kitchen sink waste is actually considered blackwater, since it contains organic matter that can feed icky bacteria, causing them to proliferate and make you sick. Even ordinary greywater is not encouraged for vegetable garden use, since it can can contain pathogens. The compromise I make is to discard my dishwater down the drain but to apply the rinse water to my garden. An even better choice would be to use that water on non-edibles, but I currently don’t have any nonedibles that require water.
If you’re at all interested in greywater reuse, I highly recommend Ludwig’s Create an Oasis with Greywater as a resource to help you evaluate a system. Ludwig’s website is also a great resource.