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Recycling Shower Water For Use In Toilets This work has been published in the Teen Ink monthly print magazine.

   Water droughts are increasingly prevalent today. If not dealt with immediately, the problem will worsen and soon affect the entire world. With 70 percent of the world's surface blanketed with water, a shortage seems impossible. However, only two percent of this water is fresh water, and it faces a continually expanding human population. Water shortages know no bounds, occurring in the vast continent of Africa where it causes great famines across the land, and in the small islands of the Caribbean sea, where water must be imported to supplement the rain.

In Puerto Rico, this past summer, half of the 3.6 million people that live on the island had to ration water, with one resident reporting that he got a half hour of water each morning. In eastern and southern Africa in 1992, 40 million people were at risk from starvation when 50 to 90 percent of the corn crop was destroyed by drought. In the former Soviet Union, the mismanagement of land around the Aral Sea has cut it from its sources, causing the lake to shrink by one-third of its former size. Closer to home, only 69 percent of Mexicans can get safe drinking water, and only 42 percent of the Haitian population.

Droughts have long threatened the human population. Small shortages are, if not commonplace, then at least expected in some areas. Major droughts, affecting whole continents, are rarer and more dangerous. What causes them is not known for certain, but El Ni"o, a periodic change in atmospheric circulation, and, more recently, the greenhouse effect, have been cited as reasons. But droughts are not the only factor depleting the water supply. Pollution and over-irrigation have also contributed. Without adequate drainage, irrigated water evaporates, leaving salts and minerals behind that can dry the surface of the ground and poison plant roots. This destroys land and usable water. Deforestation also leads to water shortages. When trees and ground cover are destroyed, the land hardens, not allowing as much moisture to evaporate and lessening transpiration. This, in turn, reduces rainfall.

Some solutions have been implemented. Desalinization plants have been created that use reverse osmosis, where a membrane filters out salt from sea water to make it drinkable. Cloud seeding, using liquid propane, alcohol, and a special snow-making bacteria, has been looked to as an inexpensive alternative to coax more rain from storms. Computers analyze weather systems, considering weather, land use, and moisture data, to utilize rain in the most effective way. Farmers now use laser guided tractors to plow fields and cut water use by 20 percent. Special gels, such as one that is spread in farmed fields and eaten by bacteria that then release water back into the soil, have also been considered. Low-water use appliances are another solution being implemented. According to the U.S. Energy Policy Act of 1992, manufacturers are now required to produce low-consumption residential toilets using 1.6 gallons per flush, and starting in 1997, business and industry must use low-consumption models as well.

If water is used as carelessly as it is today, we could soon be faced with a worldwide drought. One little known danger is that "Wars over water might erupt in the Middle East when states try to control each other's supplies," says Arno Sorer, professor of geography at Haifa University. Hundreds of species would be affected, and possibly become extinct.

II. The Solution

Our solution involves recycling shower water for reuse in toilets by redesigning the household toilet system. This supplements the fresh water supply, normally the sole source of toilet water. By employing shower water for use in toilets, the constant strain on the public water supply will be diminished, helping to conserve this precious resource.

Normally, in the act of flushing a toilet, a stopper (dubbed the flush ball) that covers the hole between toilet tank and bowl, raises and opens the tube, allowing water in the toilet tank to flow into the toilet bowl. A ball floating on the surface of the water drops as the water level drops, drawing a lever (the float ball arm) that it is attached to. The float ball arm rises, causing the inlet valve, a plug stopping the inflow of water into the toilet tank, to rise in the ball cock assembly (a pipe on which the inlet valve rests). The water supply tube is thus opened, allowing water to flow into the toilet from the public water pipe. In our solution, water flowing from showers or baths drains to a holding tank located beneath the house, possibly in the basement, rather than flowing directly into a main drainage pipe. Immediately before flowing into the holding tank, the drained shower water will pass through an inexpensive, replaceable carbon water filter, thereby removing all harmful impurities and debris. The vertically oriented holding tank will be able to contain approximately 50 gallons of recycled water. In the event that excess water flows into the holding tank, it will be diverted to the main drainage pipe line via a small runoff pipe located at the top of a holding tank, similar to that of a sink. From the holding tank, the water will be directed upwards to the various toilet tanks throughout the plumbing system, through the use of a small electrical pump, no bigger than one cubic foot. This 1/6 horsepower pump will require only 5.0 amps and 380 watts when in use (which is not very often), and the cost will be greatly offset by the savings from the water bill. No additional pressure will be placed on electric companies because the energy needed by the private pumps will approximately equal the energy saved by reducing the amount of public water pumped for toilets. A secondary water supply tube will be added to the toilet tank, through which the used shower water will flow. The secondary supply tube will be connected to the main float ball through an additional float ball arm.

Thus, the secondary water supply tube can be installed by adding a float arm to the float ball and attaching it to a separate assembly and water pipe. Through one flush, both float ball arms are lifted, allowing in water from the public water supply, as well as from the pipe connecting the holding tank to the toilet tank.

Because the water from the secondary supply tube is driven into the toilet from a nearby pump, it will be flowing into the tank with greater force than the other. Thus, the tank will be filled primarily with water from the holding tank. Any toilet system can clearly benefit and reduce toilet water consumption by at least half, whether it is old and consumes a large quantity of water, or a new, low consumption model. In the event that there is no water in the holding tank, obviously no water will flow from the secondary supply tube. Rather, the water will flow solely from the public water pipeline.

III. The Solution At Work

The entire world would benefit from this solution, especially areas suffering droughts and frequent water shortages. With this new toilet system, millions of gallons of water can be saved each day worldwide. At least half of all water used in toilets around the world will be saved, no matter where it is used. As mentioned previously, most, if not all, of Africa's 753.2 million people would benefit from this system because of its dry climate and frequent droughts. By installing it here, the amount of clean water needed would be greatly reduced, decreasing the strain on the water supply. The 37.7 million people in Mexico and the 690,000 people in the Caribbean also have many water shortages due to the limited fresh water available. Even in the United States, water shortages do occur, making this helpful in a time of need. And this resolution will help homes conform to the Energy Policy Act. One of the most important points of all, is that this system will help to conserve for the future, making it a certainty that water will not be a problem for generations to come. Once the public is made aware of the water savings possible, new homes can be constructed with this system, and existing homes retro-fitted.

In compliance with the 1992 Energy Policy Act, water saving toilets are being produced and pioneered. As the toilet uses over 40% of the water in any home, this a particularly good way to save waste. This new breed of toilets uses only 1.6 gallons per flush, as compared to the 3.5 or more gallons used by conventional toilets. Using this toilet, an average family of four would save over 8,000 gallons of water a year, an incredible amount. But with this toilet, just over 7,000 gallons of fresh water are still being used. Our solution would supplement this (or any other toilet system), not be a replacement or a competing model. Even a low-consumption toilet benefits from using recycled water. Because this system would provide approximately half of the water for every flush, there would be an additional conservation of 50 percent. With a low flow toilet, an additional 4,500 gallons could be saved. This is preferable to installing new toilets because this system will work with every toilet in the home, while to take full advantage of low-flow toilets, every toilet in the house must be replaced, a very costly alternative. The financial gain from the recycled toilet water is also considerable.

V. The Experiment

An operable prototype of our design is currently under construction, the object being to measure the amount of water that will be saved, which we approximate to be 8,300 gallons per year per household. This will be determined by evaluating the average quantity of recycled water used in each flush and comparing it to a control model, or normal toilet, where only public water is used. The amount of water saved per plumbing system in a home per year will be calculated next, to ascertain the total savings. This is the integral part of the experiment and the most important factor, because if the savings are large enough, the experiment will be a success. The amount of time that the holding tank is empty due to limited showering, although probably an extremely rare event, will also be taken into account, as will be how often the water filter must be changed. While the most important aspect of this solution is the conservation of water, consumers will be concerned about price. These tests will prove that the dollars spent on plumbing hardware (filters, holding tank, etc.) and the small electrical fee for the pump, will, in the long run, be heavily outweighed by savings on water bills. This system may be installed on pre-existing toilets and showers to help keep the cost low. At the conclusion of these tests the consumers will be shown that this water-wise system saves precious water, and precious money.

VI. Negative Effects

There are few negative effects of this technology. First, the filter should be changed at least twice a year. However this would be a small task and would not be an expensive one. There is also the cost of installation. This might run as high as $500, including labor and materials, but would pay for itself. Another drawback might be the added pipes traveling throughout the house, and the additional bulk of the holding tank. There would also be the cost of pumping this water from the holding tank to the toilet, but this should be nominal. Although this system has a few drawbacks, these are more than compensated for by the savings, both fiscal and environmental.

This solution will bring the world one step closer to achieving ecological stability. We hope that our system will eventually be implemented in all new homes, and become the standard system for toilet plumbing in the future. u

This work has been published in the Teen Ink monthly print magazine. This piece has been published in Teen Ink’s monthly print magazine.

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