Having had some less than encouraging experiences with composting toilets in the past - I won't do into details - I was very interested to read a recent article on the Rodale Institute's website about a systemic, yet eco-friendly way to deal with sewage and wastewater.
The Water Purification Eco-Center collects rainwater, which it recycles several times for different purposes before returning it to the soil as clean water again. The system uses a constructed wetland to filter the water and sewage and cycle nutrients present back into the landscape.
From the article:
"Our system works by collecting rainwater from the building's roof and storing it in a cistern underneath the building. The rainwater is then used to flush toilets after which it flows into another storage tank where water and solid waste are separated. The water is sent into a wetland area where the wetland plants and surrounding microbes scrub and clean the wastewater. Finally, the clean water flows through a drip-irrigation system to nearby perennial gardens."
Check out the video below and visit the Rodale Institute's website for more information.