by fert i'm guessing you mean the fert lab/composting toilet?

it is a humanure system (you can google this and find a pdf of the book "humanure handbook" to learn more). basically it's a composting system without the use of any water. we do our business and then put saw dust on it. that's all. it's very simple. then we let it sit for a year or two (but you can also do "faster" systems) and put it at the base of fruit trees and such (people also do plants, it's up to the user.) zero waste for sure and no need to have an expensive or complex system!