Earthships are integrated living systems where waste water and compost are dealt with in safe and clean ways.

Waste Water
Because of the scarcity of water in these parts, we have learned to deeply appreciate each and every drop. Even now, when we have water in abundance, we cannot bring ourselves to waste it. For that reason, we refuse to have a flushing toilet, which means we don’t have to contend with black water. Grey water, on the other hand, plays an integral part in our overall system.

The kitchen sink goes into a flowerbed on the east side of the house – the plants climb an arbor that forms a walkway and porch area, which shade the adobe on summer mornings.  The bathroom water goes to the inside garden to feed our year-round plants and herbs.

Grey water can be very useful in a gardening system, but you must remember that the water will be contaminated, so use caution before dumping toxic chemicals down the sink.  Use biodegradable soaps and detergents, so that the plants can sufficiently break down the waste in the water.  In fact, gardens act as a filter for this type of system, and can clean the waste water before it returns to the water table.

For a system of this kind, you will need a large enough area to properly distribute your largest load of water.  In most homes, this is never beyond 100 gallons.  The water should have a collection bed under the plants, so that the plant roots can begin the process of filtering and using the water.  In our system, we have a gravel bed that is about one and a half feet deep, covered with about the same amount of good, organic dirt from the compost.  The gravel bed has pipes running through it, and each of these pipes has holes drilled in it.  The pipes are connected to the gray water drains from the bathtub and sink.  Whenever someone uses one of these appliances, the wastewater is delivered to the gravel bed for the plants.  The plants have a good underground source of water, the water is beneath the ground, so less evaporates, and most gets to the plants.

Grey water can produce awesome crops.  Tomatoes love this type of system and will grow beyond the garden fence!

Additional Resources:

• Greywater SourceBook - Excellent and complete waste water overview 
• Grey Water - Another good waste water overview
• Earthships - An integrated system with the gardens built into the home