I have had a similar experience with ‘greywater’ systems in Portland, OR. These are usually part of the municipal systems and are classified as ‘non-potable’. I think that it is possible to use ‘greywater’ for irrigation on commercial projects – but my instincts tell me that arch / land arch don’t do it because the permitting process and long term maintenance would be a nightmare.
However, for residential work, I believe there is an easier permit process you can go through. I think a licensed plumber needs to be involved in this process. As for ‘Blackwater’ (toilet water), this can’t be done, as far as I know.
