A family in Australia has created their own tiny wetland as a part of a household grey water system. It is a fairly large DIY project, but, as the article demonstrates, not an overwhelming project. The writer even enlisted his young children to help in the construction.
Black water is toilet waste and other water that requires more substantial treatment. Grey water is non-sewer waste water from washing clothes and showers and the like. Although in most homes, both black water and grey water go into the sewer system and are handled in water treatment plants with the same processing, grey water really requires much less treatment. It is possible to find other uses for grey water, including using the water for toilet flushing or for irrigation.
The operation of the grey water system is rather straightforward. The system collects waste water from the house and directs it into a pair of tanks for short term storage and primary filtration. Two layers of sand and gravel at the bottom of a garbage can serve to clean large particles and contaminants out of the water. Water flows up from the bottom of this container, through the sand and gravel filter, and out through an outlet pipe at the top.
After the water is filtered by the sand and gravel filters to remove the large particles, the water flows into the wetland through a perforated pipe. The wetland itself is a segment of corrugated metal, like a short section of culvert pipe or a piece of an agricultural silo. To create the small wetland, a waterproof tarp was used, like a pond liner, to make the metal ring into a water tight container. This was then filled with gravel and covered with mulch. After going through the wetland, the remaining runoff water will be run to the family’s orchard to use for irrigating the trees.
As a system, this results in reuse of the water for three separate purposes. First, it is used for washing or other domestic uses. Secondly, it is used to water the wetland, which also serves as a secondary water filter for the water that is not taken up by the wetland plants. And finally, it is used to water the trees in the orchard.
Related articles on Green building Elements:
Hansgrohe to Bring Simple, Compact Grey Water System to U.S.
Elements of Building: Water
WaterSense: The New Symbol of Water Conservation
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