Very interesting.

I use all of the washing machine drain water and part of my house grey water out in the orchard etc. I have to be very careful what kinds of soaps and so on that I use, but it works out well. The rest of the out going waste water goes into septic then into a fairly deep dry well. Our grey water codes allow for this, though I live somewhat in no-man's-land.

Hope your project works well over time; sounds like a good layout.