Is anyone treating Grey Water?
Is anyone treating Grey Water?
(OP)
With LEED we're being pushed to consider reusing grey water in building (all water in the facility not coming from the toilets and urinals) for reusue in irrigation, toilet flushing, cooling tower make-up and other non-potable applications.
I haven't found a clear standard that says: do this, this and that... are there any?
What filtration/treatment would be recommended...in general?
I haven't found a clear standard that says: do this, this and that... are there any?
What filtration/treatment would be recommended...in general?





RE: Is anyone treating Grey Water?
We have looked at it. But where we typically do work, water is not a big issue so we get away with using low flow fixtures and stuff like that. Not many owners want the up front expense of the system and the maintenance just to save water.
But, from what I have heard, if you filter it to remove suspended solids and you chlorinate to kill any bugs (bacteria) in it, you can use it.
RE: Is anyone treating Grey Water?
California has the most comprehensive regulations:
http://www.watereuse.org/ca/usestable.html
RE: Is anyone treating Grey Water?
Have a look at: -
htt
for a 480p "Manual - Guidelines for Water Reuse". (about 12Meg download).
It was published in Sep04 (updated from Sep92).
There are heaps of pubs covering this subject. Try this one & if it does not cover what you want, I'll have a look for others.
RE: Is anyone treating Grey Water?
I'm in an area of the world with pretty cheap water, and the payback on these systems is infinite.
In fact, many people argue that the additional electricity cost to 'repump' the water and treat it negates the water savings.
RE: Is anyone treating Grey Water?
I would like to do one myself, just to say I did and to have the experience under my belt. However, I work mostly in the midwest and I have been told we live on top of the biggest aquifer in the US. So, grey water and even storm water reuse just is not economically feasible here.
We put in the low flow fixtures and stuff like that. Those do not impact the cost - except for the maintenance on the sanitary because the low flow toilets just do not give the drain line carry that the older toilets did.
RE: Is anyone treating Grey Water?
RE: Is anyone treating Grey Water?
There are also specific projects where the project developers have volunteered to do some specific conservation methods in order to speed the approval of a project.
There may also be certain permitting processes where you have to show that you evaluated reuse as part of your project in order to be able to get a permit for your project.
However, I have not run across any mandate to reuse water. Right now, it still doesn't make sense in most of the United States. Water reuse and zero discharge type projects are located in the arid regions of the country like the southwest and in areas prone to seawater intrusion like Florida.
RE: Is anyone treating Grey Water?
An Australian perspective...grey water re-use is big news in most Australian cities as there are water shortages caused by drought over the majority of the country.
One option has been to recycle/reuse existing water supplies. These have been investigated and implemented at different scales from the simple house system to Reclaimation plants which provide water for industry by treating secondary output from sewerage treatment plants (eg http://csrp.com.au/database/au/kwin/kwrp.html)
Grey water systems are generally more expensive than standard systems as you have extra piping to keep it isolated from toilet water, extra pumping and possibly a need for a storage tank. Also there is the cost for chemical treatment. The level of treatment is usually determined by the use of the "grey" water. More likelihood of human contact increases the treatment level of the "grey" water.
Benefits can be a reduced water cost and the associated "green" image of having a grey water system.
RE: Is anyone treating Grey Water?
RE: Is anyone treating Grey Water?
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Is anyone treating Grey Water?
You can then go for further filtration through finer sand or membranes if you wanted to. You could even go for UV sterilasion. There is no point trying to use chlorine as the chemcial usage would be huge and you would end up with vast ammounts of organo chlorines in there which would proably do more harm than good.
I've got a very simple system that I built at home using water from the shower, bath and rainwater. I've got a 45 gallon tank to act as a buffer, then use gravity to push the flow through a gravel filter and into a storage tank. It works fine for irrigation, toilet flushing.
RE: Is anyone treating Grey Water?