Should We Use Recycled Rainwater to Flush Toilets?
A rainwater capture system like this could collect water to flush toilets.
Dr. Jan Michels, Christian-Albrechts-Universi
It might sound a bit cramped, but there's an entire world of organisms that can call a drop of water their home. And, up close, they look practically out-of-this-world. Each year, the Nikon Small World competition sets out to collect some of the best microphotography. Take a look at some of this year's most stunning images of creatures that live in water. This photo from Dr. Jan Michels of Christian-Albrechts-Universität zu Kiel in Kiel, Germany shows Temora longicornis, a marine copepod, from its ventral view at 10 times magnification.
SEE MORE PHOTOS: It's a Nikon Small World After All
Frank Fox, Fachhochschule Trier/Nikon Small W
This microphotograph shows the diatom Melosira moniliformis at 320 times its size.
Jonathan Franks, University of Pittsburgh/Nik
This algae biofilm photographed up-close makes what's usually referred to as "pond scum" look like art.
Michael Shribak and Dr. Irina Arkhipova, Mari
This Philodina roseola rotifer was alive and well when this microphotograph was taken.
Dr. Ralf Wagner/Nikon Small World
This microphoto shows a water flea flanked by green algae.
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Charles Krebs Photography/Nikon Small World
Warfare in a water droplet! This microphoto shows a Hydra capturing a water flea at 40-times magnification.
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Dr. John H. Brackenbury, University of Cambri
One of the ultimate human pests -- the mosquito -- begins life as larvae, here shown suspended in a single droplet of water.
Gerd A. Guenther/Nikon Small World
Ever wonder what sex between two freshwater ciliates looks like magnified at 630 times its actual size? Now you know!
Joan Rohl, Institute for Biochemistry and Bio
This freshwater water flea is shown at 100 times its actual size.
Wolfgang Bettighofer/Nikon Small World
Closterium lunula, a kind of green alga, is shown here. This particular specimen came from a bog pond, according to the photographer.
John Gaynes, University of Utah/Nikon Small W
While it may resemble a visitor from outer space, this is what a zebrafish embryo looks like under a microscope, three days after being fertilized.
Dr. Carlos Alberto Muñoz, University of Puer
This microscopic crustacean appears yellowish-orange because it is mounted in Canada Balsam with crystals and other artifacts.
You’ll be shocked to hear this, perhaps, but the biggest single way that you use water in your household is to flush the toilet.
Older toilets use as much as 3.5 to 7 gallons per flush, and even the latest standard water-conserving models still use 1.6 gallons each time you do your business, according to the EPA. That accounts for about a quarter of your household use, on average.
There’s a big problem with that, because we still cling to the practice, which dates back to 19th century municipal systems, of having one water supply pumped into the house. That means that we’re flushing waste down the toilet with water that’s been treated at considerable expense to be drinkable. And in places where water is scarce, it’s an even bigger problem.
In drought-ravaged California, for example, the population has been flushing about 120 billion gallons per year. One water expert told the Los Angeles Times that high-efficiency toilets don’t save as much water as expected, because people tend to flush them multiple times to get the job done.
But Drexel University engineers have a solution — at least, for cities where there is ample precipitation. Instead of using potable water in toilets, why not utilize rainwater collected from rooftops?
In a study just published in the journal Resources, the researchers report that it rains enough in Philadelphia, New York, Seattle and Chicago that if homeowners simply had a way to collect the water falling on their roofs, they could flush their toilets often without having to use potable water from municipal systems.
“People have been catching and using rain water for ages, but it’s only been in the last 20-30 years that we have realized that this is something that could be done systematically in certain urban areas to ease all different kinds of stresses on watersheds; potable water treatment and distribution systems; and urban drainage infrastructure,” Franco Montalto, an associate professor in Drexel’s College of Engineering, and director of its Sustainable Water Resource Engineering Lab,said in a press release.
The solution would also help eliminate another big problem — what to do with stormwater runoff in cities, which often picks up chemicals and refuse and contaminates the bodies of water into which the drains eventually empty.
The team calculated that, with enough water storage capacity — a little more than a standard 1,000-gallon home storage tank — a three-person family in a home with the city’s average roof size would have enough water to cover over 80 percent of its flushes throughout the year simply by diverting their downspouts to collect stormwater. With even bigger storage tanks, people might be able to virtually eliminate using potable water for flushing.
If you like this idea, Treehugger.com offers a guide to installing a rainwater-supplied toilet.