High Level Filtration & Disinfection of Greywater

To: Nat Blaz <neblaz©students.wisc.edu>
Subject: Re: High level greywater filtration & disinfection
Nat Blaz wrote:
> Hello,
> I am writing you because I am involved in a greywater design project
> at the University of Wisconsin - Madison. My group and I are attempting
> to design a residential greywater system that would reuse sink, shower,
> and washer water for reuse in the washer, toilet, and garden.
> After having read through your INCREDIBLE webpage, I still have a few
> questions on filtration. What we are attempting to do is take our
> greywater and filter it through membranes and carbon cartridges, and finally
> disinfect with a UV light. What I don't fully know is what a proper filtration
> scheme would be for greywater. In particular, I need to know what size
> filter cartridges would be needed (minimum micron).
> If you have any information on this, I would be very appreciative!
> Thanks,
> Nat Blaz
> M.E. Undergrad
> UW-Madison

Hi, Nat:
First, I'm assuming you've read error: reuse of greywater for toilet flushing
in a residential context, and error: overly complex & expensive systems on
our web page Common greywater mistakes (thanks for the compliment).
Second, I'm afraid I don't know off the top of my head the optimum filter
size. I suggest you acquire and test an "earthstar" greywater filter from
Jade Mountain; this is probably a good system and I'd love to know if this
thing works for sure.


Nat Blaz wrote:
> Art,
> Yes, you may include me on your webpage... but keep in mind that the e-mail
> will only work until January, as I am graduating in December.
> As a follow-up, I thought I might tell you that we decided to filter down to
> 0.5 micron (to remove Giardia and Cryptosporidium in cyst form) and then use
> a simple U-V filter to kill off the remaining bacteria. We feel that this
> will meet California greywater code for use in toilets.
> Thanks,
> Nat

Full greywater how-to details from our store