First, a tidbit that amuses me: Ecologists have referred to human waste as “black water” for years now. How fitting.

Moving on, today’s RUST inspired lesson will be on DIY grey water systems.
What is grey water?
It is anything that goes down the drain (not the toilet). In other words, the kitchen sink, the bath tub, the laundry.Generally there may be cleaning solvents, soap, food particles or other fairly harmless organisms in it. There are some really fun and easy ( did I mention cheap) ways to do this.
Why would you want to?
The water that goes down the drain could just as easily go back into the soil and therefore back into the water table.
Why do you need to filter it?
Those soaps and food particles are best not going directly onto your lawn, for example.
What you need:
(look at used materials shops and keep an eye out for found materials)
50 gallon blue barrels, best if 2 or more.
standard poly tubing
gravel- enough to fill each barrel 2/3
plants (think anything that would live in a pond or ditch.)
*my instructor told us he just grabbed a bucket full out of a ditch along the road
*suggested: pussywillows, rice, duckweed, water celery,water hyacinth, azolla

How to:
1.Cut the barrels in half
assemble the piping so that where the water comes in the tubing is high on the barrel, then low where the water comes out

*It is necessary for the barrels to be tiered as shown in order for the water to move through the gravel as much as possible.
*you may need rubber to tightly seal the tubing
2.Fill 2/3 with gravel
3. Plant your tubers and other vegetation
*my instructor recommended dumping in some sludge from a pond you trust in order to cultivate the microbe culture that will work best
4. Try it out!

At their property in Texas they have a different system with the same principals. They set it up with found bath tubs and the same gravel and plants. The water went into the top of the tub and the drainage went out the bottom, into the top of the next (preferably at opposite ends)
The goal is to have the water move through as many of the roots and gravel as possible, because that’s where the cleaning roots and microbes are.
Here’s an image of the tubs:

Here’s a good image of a grey water system from

*Note: it is not recommended to eat the vegetation in this system. The vegetation is using the toxins as fuel and stores it in the cells.
I will post on a closed water system for growing food later.