The math of toilets

So I took a pee today.  Interesting huh?

I was at a urinal at work.  Our facilities folks occasionally attempt to do some "green" experiments.  One of these types of experiments involves trying out different types of urinals that use less, or no, water.  The little explanatory card above my urinal today told me that it only uses a pint of water per flush.  I don't know how much water a regular urinal uses per flush, but it can't be much more than that, and I must look this up on the Web for the rest of this post.  I'll be right back ...

Hmmm ...

Huummmm ...

Hmmmmmmm ...

OK.  I am back.  And evidently I was wrong.  Looks like the newer urinals tend to use a gallon and a half of water for each flush, down from two and a half gallons in the older urinals.  That is one helluva lot more water than it appears is running down that hole.  But anyway ...

The urinal next to mine was waterless.  Yes, waterless.  That means that you pee, and then just walk away.  I have used it.  I have peed in that urinal and then walked away.  No noise.  No liquids slurshing around the bottom.  Nothing.  But the strange thing was the information posted on the card above my neighboring waterless urinal: it said that that urinal, all alone, all by itself, could save 40,000 gallons of water each year.  As I was peeing I was running some numbers quickly through my head (I am ambidextrous like that).  And these numbers went like this (but with a lot more detail and less rounding here):

40,000 gallons per year / 1 gallon per flush (I thought I was overestimating) = 40,000 flushes

40,000 flushes / 365 days per year = 110 flushes per day

But this assumes that dudes are peeing at work every day of every week, and I am sure that, although some dudes pee at work on, say weekends and holidays, most of them are peeing at home or at a ballgame or at Home Depot instead on those days.  So let's assume 200 workdays per year:

40,000 flushes / 200 work days per year = 200 flushes per day

Now let's assume a 12 hour day, because although I tend to get in to work to pee on the very early side, many other dudes get in to work to pee on the much later side, even into the early and mid-evenings.  So:

200 flushes per day / 12 hours = 16.666 flushes per hour

or a flush every 3.6 minutes.

Here's my problem with this: Dudes are not peeing in that urinal every three and a half minutes.  It's just not happening.  There are a lot of people in my building, thousands of them, and lots of them are dudes, however the bathrooms are just not used that often or regularly.  I cannot prove it.  You'll just have to trust me on this important issue.  So, to me, this is false urinal advertising.

Important?  No.  Not at all.  Not even remotely.  Why the hell are you still reading this?

Interestingly, in my urinal web search just now I came upon the same claim: that a waterless urinal can indeed save up to 40,000 gallons per year.  So perhaps in other locations that do have much more regular dude-use of the urinals this is true.  But not where I work.  Trust me.