Composting Toilets: Large Scale Systems

Composting toilets can be a practical solution even for large businesses. We recently visited the Philip Merrill Environment Center, which is the headquarters for the Chesapeake Bay Foundation. It has a Platinum rating for Leadership in Energy and Environmental Design (LEED) from the U.S. Green Building Council.

After taking a tour of their offices (about a hundred people work there), we tried out their bathrooms, which looked like typical office facilities. The toilets however, are composting ones, so there is no water involved. If you look down the toilet, you see nothing but a pipe leading down into darkness. Designed by Clivus, the toilets emitted no odors — this was probably due to slight draft which was pulling air down into the pipe that lead to the compositing chamber twenty feet below. All odor was drawn away by this ventilation.

The composting toilets we featured previously on MetaEfficient were “cottage style”, meaning they were designed to be self-contained and built to serve a single bathroom. Also available are composting toilet systems which connect multiple bathroom areas into a single composting tank. For example, the Phoenix Composting System can handle daily usage by up to eight people in a household or business. The tanks are insulated, and have an efficient ventilation system with automatic controls over the downward movement of the composting pile.

EcoTech USA offers a “Carousel Composting Toilet System” which features four rotatable compost chambers. The compost container consists of an outer and an inner rotatable container. Excrement, paper and, if desired, organic kitchen wastes are disposed of into one chamber at a time. Liquid drains into the bottom of the outer container, where warmed air drawn into the container evaporates it. The resulting vacuum assures that no odor escapes into the room. When one chamber is full, the next one is turned into position, assuring that fresh waste does not disrupt the more advanced composting material.

Another option is to build your own composting toilet, more information about this can be found at the EcoWaters web site.