Big Steps in Building: Install Gray Water Recovery Everywhere
by Lloyd Alter, Toronto on 11.27.07
John notes in an earlier post that gray water re-use is, well, a gray area. However in fact it has been studied and documented, and is accepted in the IPC, or International Plumbing Code. Most municipalities use this or the Universal Plumbing Code, (UPC) as their standards, and neither is international or universal, but that is an aside. According to Ecospace:
The details: Basically what the IPC is now saying is that water coming from bathtubs, showers, lavatories (read sinks), and clothes washers are no longer required to discharge into the sewer main. This gray water is now considered collectable for the use of flushing toilets, (and subsurface landscape irrigation) if the proper procedure is followed.
In essence, you would be required to have a sensible storage tank (at least 50gal) that won’t leak connected up with appropriate piping. Additionally, they stipulate that the water must be disinfected, be stored no longer than 72 hours, and be died either blue or green with vegetable dye. (code notes here)
So it's not such a big deal; properly installed, nobody is going to be drinking green water from the tap, and it is unlikely kids are going to be playing in gray water sprinklers. Our big step in building: Put a gray water recovery system in every new house and retrofit any house where the owner wishes to have a lawn irrigation system. ::Ecospace via ::After Gutenberg
I am so glad to see alternative resources for water supply. I think this is a great, less bad, way to help preserve our very needed water as long if followed properly. If it's not them is can do more harm to people and the environment than good.
CONSUME LESS
Great! My library is building on a new wing that will be LEED certified (and much greener than any Barnes and Noble), and I'm really pushing for them to both collect rainwater (which they already do for landscaping) and add a greywater recovery system. I hope everyone sees the value of these.
I have been suggesting this for both commercial and residential construction in Dallas, TX for a while now - but with a small twist - today, I think we should require separate drainage systems to be plumbed in, but not necessarily have the pump/storage systems. If we did this, it would make it financially feasible to install such systems down the road (kindof a "baby step" approach).
In my area, most homes are built with slab foundations. They cannot be modified for grey-water reuse. By implementing such building codes, the small incremental construction costs are easily absorbed... then when the city or homeowners finally realize they need to implement storage/pumping, they actually can.
Brian
In Colorado our water agreements with other states say we can only use water once then need to send it down stream. So I don't think grey water systems would be legal here.
This code change is good news. The photo shows a "purple pipe" tap. Water that is considered "recycled water" and would be conveyed in purple pipe is highly treated wastewater, typically treated through the entire wastewater treatment process, then through a "tertiary" process that is typically reverse osmosis or specialized membrane bioreactors. Recycled/purple pipe water, from a regulatory and quality standpoint, is much different than gray water, which is for on-site uses as you noted.
The code seems a little flawed for domestic use that doesn't involve watering the garden. I certainly couldn't use the 50 gallons I'd potentially be storing in the 72 hours allowed.
I'm mixed on the whole issue as far as housing. What are uses or benefits when you have no idea what to do with the water? Could we run it into the storm drains?
I do not want to color the water and treat it if it sits around more than a few days. What about pumping it? does a normal pump work? does it plug up? Does my toilet tank get nasty and wear out faster? (I'm open to different kinds of toilets that don't need the water... that removes 1 use right there.)
Are there fish tank like things we can run the water into so we don't need to fuss with these side issues?
Makes sense to build it into the house and run the end into the sewage line so later something can be done with it but I'm not sure what to do with it. no garden, not much yard, no toilet-- then where does it go?
I think this is a great idea... we need more of it because pretty soon, water will be valued like gold and everything needs to be done to preserve it. Its sad to see about CO, wouldn't they think that using less initally would allow for more clean water to head down stream first... interesting.