Slowing The Flow

May 1, 2004
Conserving water with fixtures and technology.

With more than 70 million students attending elementary and secondary schools or colleges, as well as millions of teachers and others working in education facilities, the nation's school bathrooms consume immense amounts of water to keep toilets flushed and hands clean.

So for schools that want to be responsible environmental stewards and conserve water, the place to focus is the school washroom.

The most effective way to reduce water consumption is not to use any — that's why urinals that do not use water are becoming more common in school restrooms.

Drought concerns

Fears of a water shortage persuaded officials at the University of North Carolina at Chapel Hill (UNC) to become more aggressive in seeking ways to reduce water consumption on campus.

“We were experiencing a severe drought, and our reservoirs were drying up,” says Cindy Pollock Shea, the university's sustainability coordinator.

Officials decided to purchase 300 urinals that do not use water. So far, the university has installed about 150 of them, and each unit is expected to save about 40,000 gallons of water a year.

“We certainly think it is a justifiable investment,” says Shea.

Instead of requiring water to flush away urine, the urinals use a disposable cartridge placed between the fixture and the existing drainpipe. The cartridge holds sealant liquid, and when urine flows into the cartridge, the sealant liquid forms a barrier between the open air above and the urine below. The cartridge filters sediment from the urine and traps that sediment in the bottom of the cartridge. The remaining urine flows out and down the drain.

At schools in Montgomery County, Md., outside Washington, D.C., a pilot project calls for installing waterfree urinals in 50 restrooms.

“The biggest concern was odor,” says Anja Caldwell, green schools program manager for Montgomery County schools. “The schools will do anything to get rid of smells.”

The sealant liquid in a waterless urinal prevents any odor from the urine from affecting a restroom. Caldwell also says that the waterfree fixtures are “pretty indestructible” and stand up to student use and abuse as well, if not better, than traditional equipment.

Flushing a traditional urinal can generate a spray that spreads bacteria throughout a restroom; a malfunctioning flush urinal also can lead to overflows and standing water that is a breeding ground for germs. Those problems don't occur with waterfree urinals.

Attracting attention

On the North Carolina campus, each waterfree urinal is installed with a plaque that explains why no water or flushing is necessary. The new equipment has attracted a lot of attention.

“We've had a lot of K-12 facility directors and state legislators come up to look at them and see what our experience has been,” says Shea. “There is a large and growing interest.”

Caldwell says in Montgomery County, the interest among students in the waterless urinals has led to groups of girls touring the boys' restrooms to see what all the fuss is about.

“Kids are pretty fascinated by them,” she says.

The units cannot be installed in every washroom — in some cases, the height of the drainpipes won't allow it, and in other cases, the age of the building makes a retrofit too difficult.

“It's easiest to put them in our new buildings,” says Shea.

Caldwell says that the use of waterfree urinals can become an issue for wastewater utilities that base their billing on how much water is used. Because the urinals use no water, those utilities can't accurately measure how much waste waterless urinals put into the system.

In some jurisdictions, building codes or other regulations may prevent schools from installing waterless urinals. Caldwell says that schools might be able to pursue a waiver if regulations do not allow waterfree units.

Other savings

In a further effort to reduce water consumption, UNC is looking at the feasibility of dual-flush toilets, which are common in Europe and Canada, Shea says. Dual-flush systems use a lower volume of water — typically between 0.8 and 1.1 gallons — to flush liquid wastes and a higher volume of water — usually 1.6 gallons — to flush solid wastes.

Caldwell, a native of Germany, says that dual-flush toilets are commonly found in schools, but “here not at all.”

“Kindergartens in Germany have toilets with two colored buttons,” Caldwell says. “The button pushed determines the amount of flushing.”

Another washroom fixture common in Europe that Montgomery County is considering for pilot programs in its washrooms is a single-unit no-touch hand washer and dryer. Users place their hands into an opening, and a sensor triggers the release of heated water and soap, and finally, hot air to dry hands. The water drains from a basin at the bottom of the opening.

“There are no drips,” says Caldwell. “It keeps the bathroom very clean.”

Another green strategy that both UNC and Montgomery County are exploring is collecting “graywater” from stormwater runoff on school grounds and using it instead of fresh water to flush toilets. UNC also is looking at using reclaimed wastewater from the campus in the chillers that are part of the university's power plant.

To reduce paper consumption, Montgomery County has installed energy-efficient hand dryers in some of its bathrooms. The units are not suitable in all cases, Caldwell says. The dryers generate a lot of noise, and because many of the district's bathrooms do not have doors, the noise can be distracting for nearby classrooms.

Caldwell says that when possible, the districts seeks out bathroom partitions composed with high amounts of recycled materials, but that a greater priority for a school washroom is having partitions with coatings that make them graffiti-resistant.

Kennedy, staff writer, can be reached at [email protected].


  • 12

    In millions, the number of gallons of water the University of North Carolina at Chapel Hill will save each year by installing 300 waterfree urinals.

  • 150

    Approximate cost, in dollars, of a waterfree urinal unit.

  • 7,000

    Number of times a waterless urinal can be flushed before the sealant cartridge must be changed.

  • 3

    Number of hours it takes to retrofit one waterless urinal.

Source: University of North Carolina, facilities services division.

Go with the (low) flow

Schools can't always rely on students to act on their own to use less water. With the installation of low-flow faucets and toilets, technology can accomplish what gentle reminders cannot.

New faucets use a maximum of 2.5 gallons per minute (at 80 pounds per square inch), according to the California High Performance Schools Best Practices Manual, and some use 1.5 gallons a minute or less. Conventional bathroom faucets use 3 to 7 gallons per minute.

Faucets can be metered — delivering a fixed amount of water before turning off — and they can be controlled by infrared or ultrasonic sensors, which turn on the water when someone's hands are placed under the faucet.

Low-flow toilets generally use about 2 gallons less water per flush than conventional toilets. Federal guidelines mandate that new toilets use no more than 1.6 gallons of water per flush; older fixtures used 3.5 gallons per flush.

The manual notes that most low-flow plumbing fixtures require no special connections or fittings.

About the Author

Mike Kennedy | Senior Editor

Mike Kennedy, senior editor, has written for AS&U on a wide range of educational issues since 1999.

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