Water closets of the future

By   Don MacGillivray

While our waste water and sewage systems are working well here in Portland there may be better ways to do it.

Flushing a toilet consumes on average thirty percent of the water used for household purposes. Changing this could reduce the water and energy used to treat the sewage and retrieve valuable material.

Sewers came to London in the 1860s to remove the odors and disease associated with waste-water. A while later, Thomas Crapper popularized the modern toilet.

By the early 20th century, waste-water treatment plants appeared with simple settling and filtering processes to remove the solids and clean the waste-water so it could be returned to the environment.

It took another generation for waste water treatment plants to use biological cleansing methods. In 1972 the Clean Water Act required that sewage be treated with aerobic microorganisms.

Even today there are 2.5 billion people in third world countries that don’t have access to a toilet and adequate sanitation. They must do their business on the roadsides, in the bushes, or wherever they can.

Yet human waste in water supplies contributes to one death in ten through the communicable diseases transported by water- borne pathogens. Meanwhile, the western world luxuriates in flush toilets, giving little thought to those that must do without them.

Every year the United States yields 30 billion gallons of urine that just goes down the drain. This is the equivalent to about 8.6 billion pounds of nitrogen fertilizer.

Urine has been used throughout time as an agricultural fertilizer and it has industrial and medicinal uses. It does not contain the diseases associated with human waste. Experimental research with fertilizers made from urine is underway in many countries throughout the world and the United States is not far behind.

Human waste is a valuable, inexhaustible resource that has been used by others for thousands of years.

The most renowned example of organized use of human waste has supported food production in China for the last 2,500 years.

The value of “night soil” as a fertilizer was recognized and used with well-developed systems to enable the collection and transport of human waste from cities to fields thus enabling them to sustain high-density cities. Many cultures around the world have successfully collected human waste for agricultural use.

A Swedish study in 2004 found that with source-separation of human waste, levels of all heavy metals in the end product were reduced by ninety-five percent.

Source-separation of humanure facilitates the return of needed agricultural nutrients to the soil, without the risks of using sewage sludge.

Composting toilets collect human waste rather than flushing it into the sewer system. Many of them use sawdust or other organic matter help to compost the result in a chamber away from the bowl.

It is generally a good idea to separate the pee from the poop, as it makes composting easier. If done properly, heat is produced by aerobic decomposition, which turns the compost into humus that can later be used as a soil amendment.

There are two types of ready-made composting toilet models. One is the self-contained, all-in-one model that has a chamber under the seat and a door allows access to the collection chamber when it is time to be emptied.

The second is a more complicated system with the storage chamber in the basement or outside with a chute to transport poop to where it will be composted.

Another part of the equation is replacing the centralized city water system with rainwater, commonly known as graywater collected from roofs. It is generally clean, but not pure enough for human consumption. In most cases the resulting product is acceptable for household use such as for showering, dishwashing, laundry, toilets, etc.

A composting toilet is currently in operation at the East Portland Water and Conservation District Office in NE Portland.

Compost toilets are allowed by state law and are defined as “a permanent, sealed, water-impervious toilet receptacle screened from insects, used to receive and store only human wastes, toilet paper and biodegradable garbage. It is ventilated to utilize aerobic composting for waste treatment” (ORS 447.118).

Recode is a Portland-based nonprofit organization whose mission is to accelerate adoption of sustainable building and development practices. Their efforts are geared to working with government to change zoning and building codes so composting toilets and graywater systems are allowed and built.

Recode led successful efforts in Oregon to legalize graywater reuse in 2008 and broadened composting toilet rules in 2012.

The organization drafted a voluntary national composting toilet code with urine diversion, which creates a model code for adoption by governments and code agencies throughout the world.

Phlush is another local organization working to see that well-designed sanitation systems help to increase the health and productivity to cities, waters, and soils.

It is best to do research and connect with suppliers or others knowledgeable sources before beginning any project. Check with local authorities (the building and health departments) to find out what is required.

A revolution in waste disposal is not imminent, but is a question of time before it becomes more common and universally accepted.

Anyone planning to install a composting toilet will be one of the vanguards of those making the plunge. To really address the issue it needs to be re-framed and a discussion expanded to a wider and more diverse audience.

Water closets of the future

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