I am so glad this thread came back up.
Recently we were informed that we do not have the space to put a conventional septic system on our waterfront lot and were advised to look into the Waterloo Biofilter system. I also researched the MicroFast septic system. This field of "sewage treatment" is very fascinating.
One of the biggest turn offs - we have found with trailering is the famous "Black Tank" and dumping of ones sewage!!!
The Sun-Mar toilets have made leaps and bounds in their development over the years and when handled right - just as your own septic systems. The use of these eco-friendly systems makes PERFECT sense.
It has given Peter and I an idea to look into several eco-friendly systems that we can use in the refit of the overlander. There is plenty of room for the low profile/compact Sunmar composting toilet.
MicroFAST has a marine Greywater treatement system that might work for the greywater. But the very least we could instal a grease/sludge filter ahead of the grey tank - and a "mini-treatment" system that the grey water circulates into or is gravity fed. Thus when it is ready to be discharged the effluent values would be much lower than regular.
Small independent solar systems can be used to power the small fans and heating elements that are required.
Really worth more research - but if anyone else is looking into it or anyone who has recently used any of these systems either in your homes. cabins, cottages etc. please share it with us...