The sewer systems we use today are entirely ineffectual and unnecessary. The primary flaw in our design is that we use fresh water to dispose of feces. This is perhaps the most ineffectual thing to do with human manure — it pollutes fresh water, and it requires municipalities to maintain extremely costly sewage treatment infrastructures. Even after treatment, sewage can still wreck havoc on rivers and groundwater.

The most effective and straightforward thing to do with sewage is to compost it (or use it to produce fuel). It’s a valuable resource.

The C. K. Choi Building is a 30,000-square-foot building that is part of the University of British Columbia. The building has no connection to the sewage system. Instead it has composting toilets and waterless urinals installed.

The toilets on each of the three floors connect via stainless steel chutes to five Clivus Multrum composting systems in the building’s basement. The toilets emit no odors, because all the waste is collected in the basement and fans ensure that no odor escapes the composting containers.

The system is maintained and emptied by the Clivus Multrum company through a service contract. Every day the university maintenance staff wipes down the toilets and adds a can of wood chips or bark mulch to each toilet. Every six months, the compost (which no longer resembles feces) is removed from the system and used as a fertilizer.

Because of this system, the C. K. Choi building uses just 500 liters of water per day (132 gallons), a similarly-sized conventional building uses an average of 7,000 liters of water a day (1850 gallons) or fourteen times as much water.

But about the water from sinks and other systems? This graywater is filtered and pumped into a 300-foot-long outdoor planter bed with lilies. The final discharge is used to irrigate plants. A test by the city of Vancouver of the fecal coliform counts of the discharged water showed that it contained less than 10 CFU per 100 milliliters (by comparison swimming is permitted in water with up to 200 CFU per 100 milliliters).

The building also captures rainwater: the rain is in a 7,000-gallon tank below a staircase. It is used to irrigate the landscape, which is bordered by thirsty ginkgo trees.

What this example clearly shows is that modern buildings can do quite well without a connection to a municipal sewage system. The maintaining the building’s composting system is probably less overall than a building with flushing toilets.

More information on this topic (including many other case studies) can be found in the excellent Composting Toilet System Book by David Del Porto and Carol Steinfeld.

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.

Notes from Manufacturer:
BioLet composting toilets are efficient, compact
and reliable appliances which can be easily installed in any location.
All models are manufactured from durable, easy to clean ABS plastic and
non-corroding stainless steel and are backed by over 25 years of experience,
a three year limited warranty and toll free customer support.

Home Page: Biolet
Price: $1065-2000

The book “Create an Oasis with Greywater” by Art Ludwig is packed with information about how to reuse greywater by diverting it into your garden. What is greywater? It’s all the “waste” water produced in a house besides sewage — e.g. water from showers, sinks and washing machines.

This is a key meta-efficient technique because, when done correctly, and combined with composting toilets, it eliminates the need for municipal sewage services. It also provides your garden with water and nutrients.

The author’s own “Branched Drain to Mulch Basins or Mini-Leachfields” technique is intriguing, as are many other methods of greywater percolation explained in the book.