Muhlenberg College is picturesque–and a great place to learn about water conservation.
Is this program some odd survival camp? No, these restrictions are merely the necessary outcome of living on a small, 95-acre, bedrock island ten miles from the nearest mainland. But during summer classes on the island, more than 100 people daily depend on the island’s limited water supply for meals, drinking water and toilet flushes, in addition to bathing. Water on the island comes from a well that would soon run dry if everyone showered daily. In addition, there is a reverse osmosis machine that desalinates and filters ocean water. But that process is slow and would soon be overwhelmed if everyone acted in typical American, water-wasting ways. The stringent water-use rules allow everyone to share a limited resource.
Returning to “the real world,” I wondered how I could encourage my students on campus in Pennsylvania to save some of this most precious resource. Water is usually readily available in most American communities (although that’s becoming less true in parts of the West), so students are often unaware of its scarcity on a global level. While water covers more than 71 percent of this blue planet, flowing freshwater that we can use for personal activities, drinking, agricultural purposes, industrial needs and recreation is less than one percent of the total. More than 97 percent of the water on Earth is held in the oceans and more than two percent is locked up in ice caps and glaciers.
Thus, usable freshwater (accessible, uncontaminated) is in rather limited supply and must be used carefully. It seemed highly unlikely that I could convince my students to forego showering for days at a time, but what could students practically do to conserve water? More importantly, what would they be willing to do?
The College Try
I decided to leave it up to the students in my Fall 2004 Aquatic Ecology class. I asked them to monitor their water-use habits and propose one change that they could institute in their behavior to save water over the next three weeks, and then to actually measure how much water they would conserve by following this new regimen. Finally, I asked them to consider how they would try to convince others to incorporate the same change into their habits. The results were surprising in terms of the wide variety of changes proposed by the students, the amount of water that would be saved by their small water-saving alterations, and the variation in the water saved by students who proposed making the same type of change.
Students estimated how much water they saved by determining the flow rate (by measuring how much water ran into a large container over one minute) and multiplying that amount by the amount of time the tap was now in the off, rather than the on, position. For instance, the student who turned the water off while brushing his teeth first timed how long the water normally ran as he brushed his teeth, then measured how long the water ran during the new “military style” oral cleaning. That time difference, multiplied by the rate of water flow out of the tap, gave him his estimated water savings per day.
How did my students fare with their proposed life changes? Most of them found that their new habits were not hard to acquire at all, once they consciously made the effort to behave differently. One student bought a sponge with a soap reservoir handle to wash dishes and found that she not only saved over seven liters of water a week, but washing the dishes became easier. She was so pleased with her water-saving technique that she convinced her mother to incorporate the idea.
Another student simply decided to turn off the water while washing dishes rather than letting it run unused. Estimated savings were greater than 275 liters a week. She was surprised how easy the transition was, but noted that if she was in a hurry or had just a few dishes she was much more likely to forgo the water conservation techniques. When this student approached her peers about trying her idea, she was pleasantly surprised to hear that several of them had already changed their behavior after hearing about her project, and one of them had passed on the idea to her boyfriend.
The student who decided to turn off the water when brushing his teeth estimated that he saved almost 23 liters of water per day! Another put a filled two-liter soda bottle in the header tank of his toilet. According to the U.S. Department of Energy, toilet water accounts for 45 percent of indoor domestic water usage. This student estimated that he saved almost 53 liters of water a week by this simple change.
What About Those Bottles?
One of the student athletes in my class sheepishly admitted to buying many bottles of water and not finishing them, but dumping the remainder down the drain. She started to keep her water bottles until they were totally empty, or consolidated leftover water into one bottle that she would then drink. By making this change, she saved less than two liters per week in bottled water. However, she realized that by cutting down on the number of plastic bottles that she bought, she also saved a substantial amount of water, because her research indicated that over 180 liters of water are used in producing each kilogram of plastic. Thus, in making a single water bottle, more than five liters of water are used. It turns out that reusing water bottles, rather than buying new ones, can substantially conserve water.
However, not every student was as successful with his or her water-saving strategies. The two students who decided to hop right into cold showers rather than wasting water by allowing the stream to come up to temperature quickly abandoned that idea. Both modified their projects to allow for a shorter, carefully monitored warming period and still saved a lot of water without significantly sacrificing comfort. One student faced a potential environmental quandary: by switching her habit of heating up a pot of water for tea and throwing away the unused portion to heating up a single cup of water in the microwave. She estimated that she saved more than 11 liters of water per week, but wondered if she was using more energy running the microwave rather than a conventional stove burner.
Seven months later, at least two of my students are still following their water-savings techniques. One of them told me, “I am still turning the water off while I brush my teeth and shave. It’s so easy that there is no reason not to, once you realize how much water you can actually conserve in a year.”
H2ouse: Water Saver Home
Shoals Marine Laboratory
DR. ERIKA IYENGAR is an assistant professor in the Biology Department of Muhlenberg College in Allentown, Pennsylvania.