The first time I saw and used a waterless urinal, I was completely baffled. How does it work? How to they maintain it? Is it really completely waterless? It’s quite convenient to use, particularly for those too lazy to flush after doing the deed. Believe me, some people do not flush after using the urinals and this type is very adequate for their use. The advent of using these types of urinals was part of starting the green initiative, particularly for conserving water.

The first waterless urinal or flushless urinal was invented by a German named Klaus Reichardt. Several other companies followed suit that used a trap filled with a sealant liquid instead of water. In March 2002, Falcon Waterfree Technologies officially launched their waterless urinal product in the Philippine market after a month-long trial in the Petron Pandacan oil depot.

So how does a waterless urinal work? 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. 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. 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.

The chief benefit of using waterless urinals is their lack of water use. A single urinal can save up to 170,000 liters of water per year. Also, there is no water piping connected to the unit which keeps down installation and maintenance costs. With no water required, flush controls, sensors to adjust flow, battery replacement and other maintenance, such as repairing leaks also go away. However, they do need special regular maintenance to keep them working properly. The sealant liquid needs to be replaced every 7,000 uses. Small amounts of it seep down the drain with the urine, depleting the sealant over time. Depending on the brand of urinal, those cartridges need to be either removed and cleaned, or disposed of and replaced. Sediments from urine build up over time and clog the trap cartridges. Urinals that don’t have removable cartridges need to cleaned with a plumbing snake when sediment from the urine builds up and forms obstructions.

Other issues come to mind when using these waterless urinals. Are they more hygienic than conventional flush urinals? What about the odor? Let’s face it, sometimes you can smell that strong ammonia odor even in flush type urinals mainly because of the laziness to flush after use.

Apparently, there are fewer bacteria in waterless urinals than I thought. Studies have shown that urine is mostly sterile at the point that it leaves the body. In a normal toilet, it is actually the mixing of urine and water, not the urine alone, that encourages bacteria to grow and spread. 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. Another purpose 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. 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.

Although there are a lot of advantages in terms of savings in materials and water consumption, there are still some concerns that need to be considered when using waterless urinals. First of is with the maintenance of these units. Care should be taken when cleaning these types of urinals. Unlike flush-type systems where you can use generous amount of water for cleaning, in waterless urinals minimal to no water should be used as water may damage the sealant liquid in the cartridge.

As previously mentioned, the sealant liquid cartridge has to be replaced every 7,000 uses, but who’s counting? You can only have a rough estimate on when to replace the cartridges, but actual usage will be difficult to monitor. Replacement of the sealant liquid may also pose a potential health risk to the person assigned to do the task. Once you remove the cartridge, the trapped foul odors will escape and may asphyxiation. Proper protective gear should always be worn when replacing or changing the sealant.

Another concern will be the load concentration of waste that would go in the sewage treatment systems. Since no water is used for flushing the urine, it will be more concentrated when it goes to the treatment plant. A higher concentration of waste translates to more costs in chemical and electricity consumption to properly treat it.

Putting all the perspective for waterless urinals, it’s still up to the building owner what he wants to install for his facility. Conserving water is just one of the reasons to go green and using waterless urinals is the start of that commitment.