The system work. The water plants break down the excess nutrients in the effluent and then it is clean. The trouble is in the states it has tyo be designed by an expert and special permits are required. Each locality has its own rules so it requires proving the concept each time.
It is something that is in the tree hugger area of expertise so it is not accepted by the mainstream .
As far a specifics I am going by memeory from a TV show a few years ago so I can not say exactly how big deep and so forth. I found a link to some EPA case studies
http://www.epa.gov/owow/wetlands/pdf...s-Complete.pdf
I have seen B&Bs us it the wetlan rather than be a swamp is a gravel bed with march plants used as a garden and the discharge tunred into a water garden.
And remeber the same governement that says what needs to happen when it comes to septic systems is the same one that says factory slaughter houses are safe but a famer can't slaughter a cow and sell you the ground beef unless it has been processed in an approved oiperation thus leading to ecoli and mad cow scares.
John
PS 1 DAy until Terminal