Saturday, June 9, 2012
A graduate student at Oregon State University developed this video as part of her research focusing on urban hydrology. The video is part of a series on "feeling good" about greywater reuse in Oregon.
Note that this video describes the conspicuous mixing of greywater with rainwater, a common approach to water reuse in Mediterranean climates found in Oregon and California, and practiced in the all-waterwise state of Oklahoma and Australia. Here is a great new article describing the economics of Vespawater in the Journal of Water Sustainability.
Evaluation of Combined Rainwater and Greywater Systems for Multiple Development Types in Mediterranean climates by Jeff Loux, Rebecca Winer-Skonovd, and Erik Gellerman
This paper explores the feasibility of combining rainwater harvest and greywater capture to meet urban water demands such as toilet flushing and landscape irrigation. In Mediterranean climates, rainwater harvesting is not a viable year-round alternative water supply. On the other hand, greywater has issues of quality, storage and plumbing costs. Three land uses (single-family house, apartment cluster, and mixed use site) were analyzed to determine the viability of rainwater and greywater in combination as a realistic water supply for non-potable uses. In all three development scenarios, rainwater and greywater combined were capable of offering sufficient volume of water to meet irrigation and toilet flushing demands. Several major impediments exist to the widespread adoption and use of combined rainwater and greywater systems the largest of which may be cost. An analysis of cost revealed that onsite use of rainwater/greywater in the single-family house scenario is nearly three times more than a municipal (City of Davis, CA) water bill. The discrepancies in cost do begin to level out at higher densities. Rainwater and greywater harvesting will be most successful if it is considered in the early planning stages. Additional areas for further investigation are suggested.
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Mixing one's wines may be a mistake,
but old and new wisdom mix admirably.
~ Bertolt Brecht quotes (German poet and playwright, 1898-1956)
Posted by Todd Jarvis at 9:46 AM