Saturday, October 20, 2007

What's wrong with graywater collection?

It's amazing to me that with all of the issues that we face with our fresh-water supply, both in this immediate time of drought and as areas continue to be increasingly over-populated, that so many state and local codes forbid graywater collection and reuse.

How much would we save if we simply set houses up so that water used in our sinks and showers/tubs was automatically collected to be used to flush toilets and water plants? The technology is really very simple, and yet it's generally forbidden by the housing codes in so many areas, including in our rural county.

Why?!? I just don't get it.


Lisa Gonzalves said...

Hi there,
To find out more about greywater check out
They've got links to all kinds of projects and people!

- Lisa, Oakland CA

Kate H. said...

The same idea occurred to me this past summer.

But there's something of an answer in the October 2007 edition of This Old House (p. 26). The difficulty/cost of greywater retrofitting arises from the fact that in conventional construction (i.e., 99.99% of houses built these days), the grey water from the sinks and bathtub goes down to the sewer in the same drainpipe as the effluent from the toilet ("black" water). Putting in a separate drain system in an existing house to take the greywater to a cistern might nevertheless be cost effective, if you plan on staying in your house for ten years or more.

Me, one time during a dry period this past summer I bailed out the bathtub, dumped the water out the window onto the back porch roof, and let it drain into the rain barrel!

A siphon pump would be even more effective.

Kate H. said...

Looking at your actual question, it could be that the codes assume the common drainpipe. Does your county use the IBC?