ONLY on PMEngineer.com
Do Toilets Need A Radical Redesign?
by Corey Binns
August 20, 2007
The Western World's dependence on flush toilets could be its environmental downfall.
[This article originally appeared on LiveScience.com]
Toilets that use less water, such as the "squat toilet" in which one
squats over a hole in the ground, are prevalent in parts of Asia, Europe and
Africa, but a new historical study suggests that after decades of flushing, it
will take radical innovations for the mainstream West to adopt any new system.
"Most people can hardly imagine that other ways of handling human waste
have ever existed," said study author Maj-Britt Quitzau, an environmental
sociologist with the National Environmental Research Institute of Denmark.
"But actually, systems did exist prior to the flushing toilet where human
waste was collected within the cities and re-used in farming areas."
Since the 1900s, scientists have known that flushing away human waste comes
with environmental consequences, such as using precious, potable water. Each
year, a typical person will use almost 4,000 gallons of drinking water to flush
away 75 pounds of feces and 130 gallons of urine, according to a 2001 study by
the Swedish International Development Cooperation Agency.
While dringkin-water shortages plague millions in such places as India and in
some African nations, Westerners continue to oppose alternatives to the
flushing toilet.
'Earth Toilets'
To understand the West's preference for flushing toilets, Quitzau surveyed
historical research on attitudes toward human excrement and the technological
development of water and sewage systems. She then analyzed statistical data on
current attempts to introduce alternative solutions.
The research suggests that in order to succeed, toilets designed to save water
must hurdle our culture's long history of city planning and well-intentioned
obsession with hygiene.
Westerners have not always been addicted to flushing toilets.
In the 1850s, for example, a recycling "earth toilet" was as American
as apple pie.
It consisted of a seat placed over a container filled with dry earth. After
use, more dry earth was piled into the container. Instead of throwing away the
waste in the container, farmers put it to use in agricultural fields as
compost.
Convenience and City Planners
However, with the introduction of sewer systems in major cities and new moral
attitudes toward human waste products, the labor-intensive method lost out to
the convenience of the flush, according to Quitzau's research, detailed in the
August issue of the journal Technology in Society.
The flushing toilets required water and sewage system to facilitate easy and
enclosed removal of waste. Even with its added expense, Quitzau said,
"city planners and health personnel became some of the principal spokesmen
for flushing toilets. They were troubled about the problems that growing
urbanization brought along in the Western cities at this time."
In the city of Stockholm alone, the number of water-flushing toilets rose from
127 to more than 80,000 between 1890 and 1925, according to a study reported in
a Swedish Science Press journal. At the same time, environmentally sound earth
closets, considered less sanitary, went extinct.
Composting toilets
Although many Westerners would never consider turning in their flushing toilet
for a night pot or a cesspool, some pioneers are thinking outside the bowl.
Composting Toilets (which rely on bacteria to convert fecal matter into
fertilized soil) require no water, and urine-separating toilets rely on a
minimal amount of water to wash waste into one of two compartments in the bowl.
The technologies remain relatively unpopular because people in developed
countries are programmed—and their houses and cities are built—to flush it all
away.
"Perhaps sometime in the future," said Quitzau, "people in
Western cities could accept the idea of using human urine and feces as
resources instead of as wastes."
Until then, the unsanitary stigma will haunt some of the modern replacements
for water-flushing toilets. Quitzau says composting toilets are unfavorable because,
although much improved technologically, they still remind people of ancient,
unappetizing waterless technologies, such as the earth closet or outhouses.
Vacuum Toilet
Building flush-free toilets to satisfy the masses will not be simple and,
unlike the composting toilet, may require mimicking toilets that flush and must
be user-friendly, Quitzau said.
"This is not something, which can be suddenly changed," she said.
"Houses are built with respect to flushing toilets, not with respect to
composting toilets requiring a collection chamber in the basement. Urban
planners are taught about sewage systems and not sustainable toilet systems,
where human urine and feces are collected and transported to farming areas."
Currently, toilet technologies are focused on convenience, comfort and design,
rather than sustainability, Quitzau says.
However, the vacuum toilet—familiar to airplane passengers—is one technique
that has some potential for appealing to Westerners stuck in their old flushing
ways. The noisy vacuum toilet functions similarly to a flushing toilet. Yet the
environmental costs of the energy-sucking suction may not be worth the
tradeoff.
The most likely candidate to replace the flushing toilet will most likely
incorporate the convenience of flushing toilets with the sustainability of
composting toilets.
Photo credit: riannanworld.typepad.com.
Corey Binns
Did you enjoy this article? Click here to subscribe to the magazine.
In the AEC Store
2009 Hydronics Know How II CD
Virtual encyclopedia on modern hydronic systems.
CONNECT WITH PM ENGINEER: