Water Efficiency: When Less Water Beats Waterless

It was a happy day in the office (for males at least) when we finally got the waterless urinal in the men's room replaced with one that actually used water. 

But wait, you say, LPA increasing water usage? Doesn't that fly in the face of all the sustainability initiatives we've been promoting? Maybe at first, but a different answer emerges upon some investigation.

LPA EngineersTrends have a tendency of getting pushed to the extremes. So it's no surprise that in the realm of water efficiency, it's all about using the least amount of H2O -- or even none at all. With popular systems like LEED providing metrics for this sort of stuff, designers may get stuck on the idea that nothingness is the ideal. 

Unfortunately, when it comes to urinals, this logic comes up a bit dry (pun intended). As we discovered in the sustainability lab that is our office, there's a little quirk about waterless urinals: they have a tendency to (sorry, bad mental image warning!) clog up and become ... stinky. Turns out that a little thing called uric acid has a tendency to corrode the piping and crystallize particles which can lead to blockage and consequently odor build-up. Yes, the same uric acid prominently featured in the liquid we expel into said urinals. Such urinals also require a maintenance cartridge or oil well, harsh chemical cleaning solutions applied regularly, and custodians who know how to correctly clean the fixtures (note: pouring hot water to get rid of the stench only worsens things). And that's beside the fact that they, well, clog up and smell!! Factor in the passage of time, and even in the most ideal of scenarios (such as the LPA office), problems can occur.

Amazingly, if you compare the combined fixture and operating costs of a waterless urinal versus a regular gallon-per-flush, the no-flow becomes more expensive after only one year, and that cost only continues to mount as the years pass. That doesn't even factor irritated O&M personnel and the potential of complaints becoming so vociferous that the waterless urinal is torn out and substituted with something more traditional. Ultimately, how sustainable is a product if it is quickly replaced?

The advice from our resident plumbing engineers, Mario, Wario, and Luigi (Aaron and Chris Coppersmith and Andrew Cole, who've been kind enough to provide the technical information here), is to go low-flow, especially the new "pint flush" high efficiency urinals that rinse with a small amount of water that's enough to offset the maintenance issues of waterless urinals but still keep water use to a minimum. In fact, a waterless urinal offers zero additional LEED benefits over a pint flush, which can already reduce water use by more than 40 percent when teamed with high efficiency toilets and lavatory faucets. That's enough to earn an Innovation Credit!

So, it may not be intuitive, but a little bit of water saves a lot more than no water at all.