Blog Post

Caroma's Redesigned H2Zero Urinal

January 28, 2010

Environmental Building News first introduced waterless urinals to the green building community--back in February 1998 in a product review of the No-Flush Urinal from the Waterless Company. In the 12 years since then, we've profiled as many as a dozen waterless urinals as they've entered the market.

Most waterless urinals, including those from industry pioneers Waterless Company and Falcon Waterfree Technologies, rely on a plastic cartridge that holds a lighter-than-urine vegetable-oil fluid that serves as the sanitary trap (preventing sewer gases from entering the restroom). Though water savings are dramatic, there are at least four problems with this approach:

  1. The fluid is fairly expensive and has to be replenished periodically;
  2. The cartridges become clogged and have to be replaced periodically, which costs money and generates non-recycled solid waste;
  3. If these waterless urinals become very common, the plant oil trap fluid may become a problem at sewage treatment plants; and
  4. Without periodically flushing a larger volume of water down the urinal drain, uric acid salts may build up and eventually clog the drain pipes.
This latter problem is a significant--as we have learned at our BuildingGreen office, where we've used a waterless urinal since 1998. A few years ago we removed ours to figure out why the drainage had deteriorated so significantly and found tremendous salt build-up. It wasn't a pretty picture, and it took some messy work to ream out the pipes! Here's our EBN article from 2004 addressing problems with waterless urinals: "Why Non-Flushing Urinals Fail (And How to Prevent Those Failures."Caroma, the Australian company that pioneered dual-flush toilets several decades ago and remains a world leader in water-conserving plumbing fixtures, has a great solution to these problems.

Caroma's H2Zero urinal features an elastomeric mechanical seal--a curled airtight diaphragm made of silicone. Urine flows through this seal, then it closes off until the next use. There is no plant-oil fluid required to achieve the sanitary seal--so there's no fluid to replace and nothing that might make the sewage treatment plant have to work harder.

We reviewed this urinal in EBN when it was first introduced from Australia in 2007--before any of the urinals had been installed here. The problem was that it didn't satisfy U.S. plumbing codes, which require a liquid trap for sewer gases, an issue that has also spelled problems (covered in this article) for an alternative trap meant to last a "lifetime."

Caroma argues that this requirement for a liquid trap is silly and unneeded, but the company realized that it would be easier to redesign its H2Zero urinal than to change U.S. plumbing codes, and that's what it did.

The new H2Zero urinal, introduced at the 2009 Greenbuild conference in Phoenix last November, has the same elastomeric, mechanical seal as before, but downstream from that is a liquid trap provided by urine. Because there's an airtight mechanical seal above the urine, there isn't a problem of odors from the urine entering the restroom, and the liquid trap satisfies our plumbing codes.

Caroma suggests that the elastomeric seal should be replaced after 10,000 uses, but the seal is likely to last much longer in typical applications.


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A big advantage is that custodians can pour a bucket of water down the urinal periodically to help keep uric salts from being deposited on the drain lines--and this can happed without washing an expensive plant-oil trap fluid down the drain.

Though I haven't had personal experience with the product, I think this is likely to prove to be the best waterless urinal out there.

A quick check of online prices found the H2Zero going for $550 to $650.

For more information:

Caroma USA


www.caromausa.comI invite you to share your comments on this blog. What's your experience been with waterless urinals or this product specifically?

You can also follow my musings on Twitter.

See more on this product in the GreenSpec Guide

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February 11, 2010 - 8:39 am

The Chicago article is one of those unfortunate items again where special interest groups are still fighting water conservation despite their mayors procalamation to become the greenest city in the US. Copper drain lines, while rarely used these days, are still present in some installs. However, the problem with copper has always been that as a sofetr material it tends to channel, which is a known fact over the decades. This on flushed urinals and toilets. If one then installs a non-water using urinal on a line that already has started to channel (who looks into the lines before install? ) the when the line breaks after some time it is assumed that it is due to the non-water using urinal. Nothing can be further from the truth!
The urine deposited in the drain line itsel does not create any wild chemical reaction and deterioration of lines. But if stated by trade associations weight is given to it. I find it interesting that when we talk to trade assoiaction members themselves and answer their questions plus show them chemical facts, they are very positively surprised and start to support the systems. In group think ,however, with intent, it is a different case.

February 7, 2010 - 6:40 am

I would be interested to hear comments regarding waterless urinals, copper pipe and use in public places with a lot of traffic. Please see 2/6/2010 Chicago Sun Times article on waterless urinals at Chicago City Hall,,CST-NWS-stench07.article

February 8, 2010 - 4:06 am

Very interesting article, Helen. We are clearly still climbing the learning curve with waterless urinals. It sounds like copper is a significant problem and that waterless urinals should not be used when building codes require the use of copper drain lines. (I think there are few places where such a requirement is in place.)

There are other strategies for reducing problems with waterless urinals--such as installing them downstream of sink drains, so that water draining from sinks flushes urine out of the pipes (after the urinal drains T into those pipes).

The apparently common practice of putting other fluids in urinals is another problem; I'm not sure how to deal with that. I suspect it's mostly a matter of education of custodial staff and users.

February 3, 2010 - 11:44 am

Appreciate it. We find that our EcoTrap inserts are recycled about 30% of
the time, but I also know this number has and is increasing as facilities are becoming more aware of it and make more efforts to recycle in general.
With more ordinances coming in cities and communities, I would think
recycling of all materials, incl the traps, will improve. Our is a
polyprop and easier to recycle than ABS parts.
Hope this helps.

February 3, 2010 - 11:21 am

Klaus, you make a lot of good points, particularly about waiting to see how products perform.

One fairly minor question I have is how often do waterless urinal cartridges get recycled? You make the fair point that they are "recyclable," but almost anything is "recyclable" -- the question is what percentage of the time does it happen?

I haven't seen any data on this -- I'm wondering if you have. We have a Waterless-brand urinal in our office and we do not have a way to recycle the cartridges, that I know of.

February 2, 2010 - 9:52 am

Hi Alex,
thanks for another write-up on non0water using urinals, as you have done over the years.
Great that you keep all informed. However, as the original manufacturer and now with sales of our product for the past 18 years, I like to correct a couple of things mentioned, without trying to make a sale here:
"fluids are expensive": that depends on whose product is used. The less expensive ones will have a definite ROI versus the water and sewer use of a flushed urinal.
"inserts are expensive"that certainly depends on which urinal is bought. Same as above, the less expensive ones have a real ROI for the facility guy.
"cartridges become clogged": that is what they are supposed to do, so that the debris and sediments from urine do not clog the drain lines. Urinals without a removable insert get completely caked up.
"and creates non-recycled waste": depends on whose prodcut you buy. Most are recyclable.

"without flushing water ..." : Unfortunately this statement shows that non-water using urinals are still not understood-namely, that without the water hard encrustations in waste line no longer occur. Adding water into waterless urinals will harden contents of traps and accelerate clogging. Once this is understood by plumbers plus that those fixtures having a full 2" outlet, plumbers love them.

The Caroma unit is again one of the last fixtures to enter the market. With lots of parts and very expensive when cmpared to what is on the market. That Caroma had to change their design to code also shows you that it will may not perform without problems.

The other issue is: our product had to show its potential and working after having been in the market for at least 5 years. Why the rush to promote products that have been in the market less than a year! Let's see first how they perform. The same with 1/8 gal. flush urinals! There are pysical limits to scour a trap with so little water, the drain diameter has to be reduced to accomplish that plus the higher content of urine to water will have drain line problems. Why not run all of these for 5 years andf then see! Making it apples to apples.

What we all have to understand is this: if we want to assure our future water supply and also reduce costs, we need to determine what works best. As with other product lines, some work better and some do not. In addition, if it can be shown that bottom line a product costs less and reduces maintenance, might that not be the answer everyone is looking for. What use is a carbon footprint number if you have no water to drink! It will not be perfect, as nothing truly is, but net results should count.
Kindest Regards
Klaus Reichardt
Founder and CEO
Waterless Co Inc.