10 Stand-up Facts About Waterless Urinals

It might seem like a urinal that doesn't use any water would be complicated, filled with moving parts and pumps and complex valves. But actually, waterless urinals are relatively simple. Most use gravity and a specially designed trap chamber filled with a liquid called sealant, to send waste cleanly down the drain [source: Waterless]. Depending on the manufacturer, the sealant can be formulated differently. But all sealants are lighter than water, don't evaporate and are usually made at least partially from oils (like vegetable oil) [source: Waterless].

If you look at a waterless urinal, you will see a circular dome surrounded by tiny channels for water to move through. This dome is the trap, a removable cartridge that makes waterless draining possible. In the most common design, the waste flows into the trap through the series of circular slits along the top of the cartridge. As it enters the cartridge, the urine filters through the sealant, which stays on top because it is lighter than water [source: Reichardt]. The urine then flows down into a central reservoir. In the center of that reservoir is an open pipe that drains out into the bathroom's waste line, the same waste line that standard urinals use. The urine slowly fills up the reservoir, and when the level of liquid gets higher than the rim of the pipe, the excess drains out [source: Reichardt]. So, at all times, there is a small amount of urine inside the reservoir. As more and more men come and use the urinal, the old waste flows out and the new waste flows in.

Just the phrase "waterless urinal" sounds like some kind of smelly malfunction, not something you would actually want to use or live with. Controlling unpleasant smells was actually one of the main problems in the development process for waterless urinals [source: Davis]. Sewers are full of all kinds of odors, and even gases that can be health hazards if they escape. One of the main purposes of the sealant that floats on top of the urine in waterless urinal trap cartridges is to keep any foul odors from escaping through the pipes [source: Waterless]. The sealant stays floating on top of the urine in the trap at all times. The seal that it creates also keeps the smell of urine that is sitting in the trap for long periods of time from escaping. Also, since no flush is needed to empty out the urinal, there is no chance that urine will pool in the bowl. Waterless urinals have ultra-smooth bowls designed with a steep enough slope that all liquid will flow directly down into the reservoir without pooling up [source: Waterless].

At the point that it leaves the body, urine is mostly sterile. In a normal toilet, it is actually the mixing of urine and water, not the urine alone, that encourages bacteria to grow and spread [source: Reichardt]. Once the particulates and minerals in urine react with the minerals and chemicals in water, bacteria begin to thrive. Since there is no water introduced in a waterless urinal, there is less bacteria growth. The sealant in a urinal also keeps it from being exposed to air, where bacteria travels and spreads. Flushing urinals can also send small water droplets into the air, which can spread bacteria throughout the bathroom and even onto your hands or clothes [source: Waterless]. Waterless urinals don't create that problem.

Still, like any bathroom fixture, you need to clean waterless urinals regularly to make sure they stay clean and bacteria doesn't find a place to latch on and grow. Cleaning them is relatively simple: You can use a household cleaning solution and a sponge or cloth to wipe down the exterior surfaces [source: Zero Flush].

Waterless urinals are truly waterless. They don't use some water, or a little water. They use no water. So the amount of water you can conserve by installing one is essentially equal to the amount of water used by the urinal it replaces. Most urinals in use today use somewhere between 1 and 3 gallons (3.7 to 11.3 liters) of water for each flush [source: Reichardt]. That variance is so large because older urinals use a lot more water, and newer ones tend to use less (because of an increased focus on conservation). Urinals produced during the 1990s and '00s use closer to 1 or 1.25 gallons per flush [source: Stumpf]. Some extremely low-flow fixtures use even less. Older urinals can use closer to 3 or 3.5 gallons (11.3 to 13.2 liters) of water for each flush [source: Stumpf]. Other variables include the amount of use the urinal gets. A urinal in a busy office where 100-plus men work will use more water than one located in a small restaurant or gas station. Taking all of the variables into account, a single urinal in a workplace with a few dozen employees can save about 45,000 gallons (about 170,000 liters) of water per year [source: Stumpf].

The vast majority of waterless urinal manufacturers design their fixtures to fit with conventional plumbing systems [source: Stumpf]. Many large fixture producers, like Kohler and Sloan, even have their own waterless toilet lines. Of course, it makes business sense to keep them adaptable since waterless urinals can be a tough enough sell as it is, for some. Specifically, waterless urinals usually fit standard 2-inch drainage lines, or can be adapted to fit 1.5-inch lines [source: Waterless]. Since they don't need any water for flushing, they don't need to be hooked up to a second line for potable water supply.

If you've ever seen a waterless urinal, you might have noticed a pipe protruding from the wall above it, with apparently no purpose. That pipe is the unused water supply line, which needs to be capped when waterless urinals are installed to replace traditional urinals. Since waste water won't be flushed out with a fast moving stream of water, the pipes leading from the urinals to your waste line need to be sloped enough that waste can drain out easily. Those pipes need to have a slope of at least a quarter of an inch per foot [source: Stumpf]. If the lines aren't sloped enough, they will have to be modified, which involves replacing the few feet or less of pipe leading from the bottom of the urinal to the main waste line [source: Falcon].

Compared to flushing urinals, waterless urinals need less maintenance. Manufacturers frequently point out in their promotional materials that their urinals very rarely leak, and don't have valves or handles that need to be replaced [source: Waterless]. All of that is true, but they do need special regular maintenance to keep them working properly. The sealant liquid needs to be replaced every 1,500 uses (two to four times a year) [source: Reichardt]. Small amounts of it seep down the drain with the urine, depleting the sealant over time. Some waterless urinals also have removable trap cartridges. Depending on the brand of urinal, those cartridges need to be either removed and cleaned, or disposed of and replaced. (Many manufacturers will recycle the cartridges for you.) Sediments from urine build up over time and clog the trap cartridges. Urinals that don't have removable cartridges will need to cleaned with a plumbing snake when sediment from the urine builds up and forms obstructions [source: Stumpf].

Waterless urinals were first invented back in 1991. But the invention has only started to be adopted more widely since around 2006. That year, urinals were accepted as an alternative specification in both the Uniform Plumbing Code and the International Plumbing Code [source: Davis]. Those two codes serve as the basis for most state and municipal plumbing codes in the United States. After this landmark, waterless urinals were made legal in most parts of the country. Before that, only a small number of local governments had enacted their own laws making waterless urinals legal. The plumbing profession argued that waterless urinals were unsafe, prone to allowing toxic sewer gas to escape from drainage pipes. Once the plumbing industry was convinced that waterless urinals could be installed safely, thanks largely to improvements to the technology, states began to rewrite their plumbing codes to allow them [source: Davis].

Over the course of the 2000s, waterless urinals started to become more widespread, emerging as an option for businesses and public organizations looking to conserve water [source: Davis]. Today, many manufacturers produce them, so they aren't as much of a niche boutique item as they once were. Just like any other type of fixture or appliance, waterless urinals come in all different shapes, sizes, styles and colors. The cheapest urinals start at around $250 each [source: Reichardt]. Those cheaper urinals are usually plain white, and resemble the tall bowl shape of many traditional urinals. Fancier urinals in designer colors, with more sleek designs, can run closer to $1,000 [source: WaterWise Technologies]. In other words, waterless urinals are no more or less expensive than traditional toilets. Also, some municipal water systems will give you a rebate for installing them as an incentive to decrease demands on the local water supply. Those rebates range from $60 in Los Angeles, to as much as $400 per urinal in San Diego county, just to name a few [source: WaterWise Technologies].

Waterless urinals are an option for home installation. You can take advantage of all of the benefits that big companies and large facilities can, like saving money on utility bills and conserving water. You can save 1 to 3 gallons of water for every flush, and they are relatively inexpensive to purchase and install. Assuming you have two men in the household, a urinal can save about 3,250 gallons (about 12,302 liters) of water per year [source: Wilson]. Of course, there is a major limitation to keep in mind if you want to install a waterless urinal for home use. Obviously, only the men in the house can use it, so the potential for conservation is limited. Even if you don't have any women in your household, you will need to keep your old toilet bowl for your other bathroom needs and female guests. So, if you decide to install a urinal, it should be a second toilet. With that in mind, make sure you have room for both fixtures in your bathroom.

Because of their cost effectiveness and water efficiency, waterless urinals have become popular with government agencies. For example, the U.S. Army has mandated that, as of 2010, all new military facilities be outfitted only with waterless urinals [source: Davis]. School districts and municipal government buildings have moved toward waterless urinals, too. For example, San Diego's public schools have been using them since 1997 [source: San Diego Unified School District]. Since waterless urinals count toward LEED certification points, businesses and individuals have also installed them to help green their buildings. Large attractions and public facilities, including the L.A. Coliseum, the Georgia Aquarium and even the Taj Mahal in India, have begun switching to waterless urinals, too [sources: Georgia Aquarium, Cutraro].