Permaculture in New Zealand

Does anyone have the below system,is it reliable??, are there any other alternatives??

I am trying to decide on a system to treat our black and grey water. I am interested in a flushable system that has a separate grey and black water system. The black water is treated with filters and tiger worms in a wormarator and the grey water is seperately treated and then can go on he garden through drip lines. This system is offered by Natural flow systems in Kaipara district. Help appreciated,thanks simon.