How Waterless Urinals Work

When I first heard of waterless urinals, the innovation excited me. But my next thought was, Do they really work?

I have often praised the invention of the urinal—such an unpretentious contraption and nothing like its pompous brother "John." It requires little attention, uses little space, and allows for quick business. Still, it amazes me that something can make it any easier for men to pee!

(With respect, ladies: There are women urinals, too, but we all know that urinals are overwhelmingly used by men.)

So how do they work? There are a few designs that utilize the same concept. A special oil-based sealant is used inside a drain trap mechanism, often a cartridge or valve. The property of the sealant is the key: Its density is lower than water and since urine is 95 percent water, it sinks through the sealant. Put another way: the sealant floats.

Drain trap designs vary with different companies, but most work the same. When a person urinates the urine is drained by gravity through an access on a cartridge or pipe mechanism that connects to the plumbing system. A trap area houses the sealant.

Because of its low density, the sealant acts as a guard, or “trap door," and prevents urine and odor from backing up. This trap compartment opens to the outflow pipe on the rear end; and when enough urine has filled the trap, any excess will exit the unit. Simple.

(View the video on the right for a visual of this process. There are different but similar methods; yet this video is one of the better ones available.)

The obvious benefit of these toilets is the drastic reduction in water usage. Figures vary but it is safely assumed that a facility, including a home, can save up to 30 percent on total water consumption. This is important because the toilet is the largest water consuming appliance in the home.

Waterless toilets and urinals are already being used in corporate facilities, entertainment venues, and state and federal buildings. In fact, arid Arizona mandated the urinals in all state buildings in 2004 as a means of conserving water. These urinals work for home use as well where it isn't too shabby an idea for a family with several males.

The urinal typically costs $350-$600; cartridges and sealant range $40-$70. Drain trap units do require change-outs but only about three or four times a year (about every 7,000 uses). The toilets pay for themselves anywhere from six months to three years depending on use—unless there are problems.

Some people don’t like the new toilets, especially plumbers unions! Still, there are legitimate reasons for the backlash. Stink and stain is one of those reasons, something that makes many people leery about the toilets from the start.

For instance—and embarrassingly—the California Environmental Protection Agency removed 56 waterless urinals installed in its LEED-certified Platinum high-rise in 2010 due to excess maintenance issues and the complaints of odor from male workers.

Part of the problem in this incident was the building's inability to support the urinals due to plumbing setup. Prospective buyers must be aware of this possibility before investing.

Further, urine solids can wreak havoc on pipe systems in the absence of water. Water in a traditional urinal literally flushes everything out of the system; with waterless urinals, however, the solids cling to pipes. Clogged pipe horror stories abound. Waterless models do require weekly flushing with water for this reason.

Owners must also be careful not to clean with harsh chemicals. This can result in a breakdown of the sealant and lead to odor.

I am not of means to build my dream home any time in the foreseeable future, so I’ve often employed a robust and unsparing imagination about it and the things that might furnish it. A urinal has always been one of the niceties I include for myself.

The verdict on the waterless urinal is still out, for me at least. Not having much experience with them, other users may swear by them. I have used one although I thought something was wrong with it. I recall being frustrated at having no handles, no water, and no way to tidy up. The chore of trying to be clean—go figure!

It seems like this innovation is at the last stage of development. It is clearly a sustainability marvel—but do you ever get around the need for water? I have often warned against advancement for the sake of advancement. It only turns into experiment. So maybe a near-waterless urinal might be the better option...for now.

(So no flushing guys—but you still have to wash your hands!)