Toilet Talk: Eco-Friendly Toilets

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Modern, sleek, and energy-efficient, Toto’s Neorest tankless toilet offers a cyclone flush engine and dual flush water-conservation mode.
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Kohler’s ultra low flush models (ULF) feature exceptional flushing power while saving water.
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Modern, sleek, and energy-efficient, Toto’s Neorest tankless toilet offers a cyclone flush engine and dual flush water-conservation mode.
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Modern, sleek, and energy-efficient, Toto’s Neorest tankless toilet offers a cyclone flush engine and dual flush water-conservation mode.
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Flushing Facts
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These waterless urinals have been used with great success at Stanford University’s Jasper Ridge Biological Preserve.

The humble flushing lavatory is the watershed of modernized society. However, there may be a dirty little secret hiding in that older-model water closet: It could be swallowing almost a third of all the water used at home–more than any other appliance or fixture. At the rate of three to seven gallons per flush, each person could be washing up to 35 gallons of potable water down the john every day–about 127,000 gallons a year.

Americans already consume three times as much water as Europeans and seven times that of the rest of the world, according to the World Resources Institute. The old porcelain potty and its guzzling ways are enough to make anyone flush–with embarrassment. Yet you need not eliminate indoor plumbing and build an outhouse. By replacing your old fixture with a newer, low-flow one, you can reduce your home water use by 20 percent.

Changing out an old toilet will even save tax dollars by minimizing water and sewer infrastructure use and deferring capital expenditures on replacements and expansions. Your local water district may pass the savings along to you in the form of toilet replacement rebates, special purchases, or financial assistance, thus lowering your out-of-pocket expense even more. And don’t forget to check with your local recycling services; some take porcelain or plastic.

Best of all, upgrading to a new toilet helps the environment. If all U.S. households were to install water-wise toilets and other fixtures, water use would decrease by 30 percent, saving an estimated 5.4 billion gallons per day–or almost 2 trillion gallons a year-according to the American Water Works Association (

Ultra-low flush toilets (ULFs)

Unsure of the age of your commode? Peek under the tank lid to find the date stamp. Anything installed before 1994 may be suspect; after that date, federal law required ultra-low-flush (ULF) toilets in all new installations.

ULF models need a mere 1.6 gallons or less to do their dirty work. The gravity-fed design is essentially the same as in years before, but the ball cock has been replaced by a valve/siphon mechanism. With a life span of twenty years, a ULF toilet costs as little as $100 if you purchase a no-frills white, round version and install it yourself. In one year, a family of four may save 8,000 to 20,000 gallons of water and $50 to $100 in water bills. State-of-the-art, 1.4-gallon flushers, like Kohler’s Class Five line, can conserve even more. And, as toilet technology improves, so does performance. Although high-efficiency, low-flow ULF potties initially got a bad rap because users reported double flushes and clogs, complaints are dwindling.

Dual-flush models

For the environmentally savvy homeowner, dual-flush loos may be the latest and greatest invention. The flushing mechanism provides less water or more, depending on the need; simply press one knob for liquid waste or another for solid. The light-flush option uses 25 to 50 percent less water. Average potty goers will choose it about 80 percent of the time–cutting water use in half or more. Although dual-flushers are new to the United States, they’re required by law in Australia. Caroma, an Australian company now importing to the United States, has been the world leader in dual-flush technology, but others are entering the market.

Mechanical dual-flush models with simple levers or buttons start at $250, and the money can easily be recouped through lower water bills.

Pressure-assisted flush

Familiar in public restrooms, pressure-assisted flush mechanisms reduce water consumption by 20 to 45 percent more than gravity-fed ULFs. Compressed air inside the tank forces water into the bowl for a more efficient rinse. This style has yet to catch on at home, in part because the noise factor can range from noticeable to startling and the pressure-assist mechanism can’t be retrofitted to existing standard, gravity-fed toilets. The primary benefit is bowl cleanliness and fewer clogs, although manufacturers are working to ensure the same results with gravity-fed ULFs.

Waterless urinals

The waterless urinal is gaining surprising popularity. Instead of a traditional water-cleansed drain, a cartridge traps and moves urine through a sanitary chamber filled with a biodegradable oil and alcohol mixture that also prevents sewer gases from entering the bathroom. Monthly cleaning with a few gallons of water and a nonabrasive substance is necessary. Most models use cartridges that must be replaced after 6,000 or more uses.

Although a water-free urinal may sound unsanitary, studies indicate that water and hands are the primary carriers of disease–neither of which are factors because there is no flushing. Home use is limited at this time by gender (although urinals for woman are not uncommon worldwide), and by design factors that demand high use for the cartridges to remain useful.

Composting and incinerating toilets

In areas where homes already have water and sewer lines and where local codes are restrictive, composting and incinerating units may not be feasible. However, these toilets have come a long way since the 1970s, when do-it-yourselfers built, maintained, and emptied sawdust-laden, odiferous chambers. Now cleaner and sweeter-smelling, manufactured composting toilets turn human waste into sanitary, usable compost, either in a self-contained unit or an underground system.

Incinerating models use electricity or gas to burn waste into a fine ash. The expense of the unit, the installation cost, and the gas or electricity needed usually make these too costly for practical consideration in typical homes.

Both composting and incinerating units must be emptied and maintained periodically. Because of the small capacity, self-contained composters–which must be emptied frequently–are suitable only for occasional use or vacation homes. These almost waterless toilets are being adapted for common household use and may become more affordable and practical soon.

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