Back in 1992, the Energy Policy Act was passed, which established the water conservation standards for fixtures – mainly water closets, shower heads, and faucets. This was done to save an estimated 6.5 billion gallons of water in the United States per day. Locally, the City of Dallas supplies water to more than 25 nearby cities, a population of over 2 million individuals. Dallas’ drinking water comes from five lakes: Grapevine, Lewisville, Ray Roberts, Ray Hubbard, and Tawakoni. There are two other lakes, Fork and Palestine, in reserve for future supply. However, with an ever increasing population, we need to be reducing our usage now.

The Energy Policy Act of 1992 provides a great starting point, but can be taken further. LEED Water Efficiency credit 3 deals with water reduction of fixtures above and beyond the requirements set forth by the EPA. One point can be achieved with a 20% reduction; increasing that reduction to 30% can garner you another point.

If you’ve worked on a LEED project, there is a good chance that the subject of waterless urinals has been brought to the table. For new construction, urinals using flush valves of 1 gallon per flush are used. However, in existing buildings, it is not unusual to see flush value that use anywhere from 2 to 3 gallons per flush. On average, a flush-type urinal can use 45,000 gallons of water annually. As you can see, waterless urinals that use no water can significantly reduce a building’s water usage.

So, how do waterless urinals work? A removable cartridge is inserted into the drain. This cartridge has a built-in trap that contains a layer of sealant that floats on top of both water and urine. Urine, which is heavier than the sealant, passes through the sealant and then out through the trap. The construction of the cartridge allows urine, which is heavier than the sealant, to pass through the sealant. The sediment settles out and is contained in the cartridge, while the remaining urine passes into the drain and into the sewer system. The sealant also forms a seal that prevents sewer gas from leaking out.

Personally, I am a big supporter of waterless urinals. Overall, I feel that the time spent annually maintaining waterless urinals versus flush urinals is less. There are no moving mechanical parts to replace, and there are less risks or damage that is associated from breakage, stopped up drains, or vandalism. And then of course there is the water savings. However, as with any new technology, there are some very critical items that need to be addressed before an Owner decides to install waterless urinals.

During construction, it is imperative that the drain line is installed per the manufacturer’s recommendation (normally ¼” per foot). With flush type urinals, there is a gallon of water (minimum) flushed through the drain line. This quantity and force often overcomes a no-slope or negative-slope condition. This is not the case with a waterless urinal. Drainage is directly related to the quantity of urine in the trap, and occurs much more slowly. A no-slope or negative condition can lead to urine remaining in the drain line, and eventually causing issues. At the same time, too much slope can also cause issues. A large slope can cause a vacuum to occur, which will suck out (that’s a technical term by the way) all the fluid in the trap, including the sealant.

As bad as this sounds, this is a relatively easy condition to fix. There are many different types of flanges or supports that can be attached to an existing drain line. These flanges are affixed to the wall surface, and keep the drain line at a proper elevation. These flanges are also very convenient to use in a retrofit/renovation situation.

The other item to be aware of is the different type of maintenance required. With flush type urinals, maintenance is normally required by a plumber. In a waterless urinal, this responsibility is shifted to the custodial staff. Daily maintenance is very simple. The urinal needs to be cleaned with a damp sponge and a disinfectant. It is recommended that harsh or abrasive chemicals, along with large quantities of liquid, are not used as they will cause the sealant to break down faster or be flushed from the trap.

The traps also have to be replaced periodically. This replacement will depend on usage, but it is typically three to four times a year. Sediment and contaminants are kept in the trap as opposed to entering the drain. This sediment eventually builds up and requires maintenance. We have found it more cost effective to replace the entire trap (approximately $35 each) as opposed to cleaning the trap. When replacing the trap, it is very important to flush the system with a couple gallons of warm soapy water. This removes the calcium carbonate (urine salts) build-up from the drain lines. Falcon, one of the largest manufacturer’s of waterless urinals, puts out a very easy to follow step- by-step guide for maintenance.

Once again, let me reiterate how much I support the use of waterless urinals. However, as with any new technology, improper installation and improper training of staff can lead to serious issues. This is an example of an extreme situation, and occurred because of improper slopes and no-maintenance over a period of 18- 24 months (the stars also had to be in proper alignment). You will probably (and hopefully never) run into these issues, but, they can happen...

Calcium carbonate (urine salt) is caused by a reaction between urine and water. Flush type urinals actually cause a larger reaction because of the quantity of water used. At the same time, the quantity of water flushes these contaminants directly into the drain lines. With waterless urinals, you have a much slower reaction because of the absence of water. But at the same time, there is nothing to flush the calcium out of the drain lines. This is the reasoning behind flushing the system when replacing the traps. At the same time, you can have sediment build-up. Older style cartridges could allow the sediment to build up enough in the trap and extend into the drain line. The newer cartridges have a smaller neck, which clog up with sediment and stop working before being passed into the drain lines. However, when these two items collide, you can end up with the following condition. You can still clean the line out, but it may require the removal of the urinal from the wall.

No-slope or negative slope can also cause issues. Without proper maintenance of the traps, urea (the caustic portion of urine) can build up and overflow into the drain line. Couple this with other sediment and calcium build-up that can trap the urea in the low spot of the drain line, and it will eventually eat through the copper line. This also occurs with flush type urinals, but takes significantly longer (years and years).

In a couple years, use of waterless urinals will be so common that these installation and maintenance issues will become the norm and go away. Until that time though, keep the above in mind, and enjoy the water savings!