Are We Drinking Dinosaur Pee or Not?

Much has has been made of several recent statements that we are indeed drinking 'dinosaur pee' because the same water that is around today was around then as well. 

So are we drinking dinosaur pee? If you want to cut to the chase, scroll down to the bottom. Otherwise, brace yourself.

On page 16 of  The Big Thirst (read my review), Charles Fishman starts discussing the 'resiliency' of water and then on page 17 suggests we are drinking dinosaur pee because the water molecules that are around today have been around for at least for the past few hundred million years  - 'No water is being created or destroyed on Earth' (page 17). Another book, The Future of Water: A Startling Look Ahead , by Steve Maxwell and Scott Yates, states:  

The water that dinosaurs drank is the same water we drink today, and the amount of water in the world is the same, too. Fossil fuels get burned and are gone forever. Water remains.

In response to her publishing of this quote in an email to the AWRA membership,AWRA Director of Marketing Mary Ashton received this thoughtful response from a reader who is a water researcher with outstanding credentials:

This is a common and widespread mis-perception that greatly detracts from much more important messages regarding water. This fallacy only serves to perpetuate a very common misunderstanding regarding a concept central to the water cycle. This misunderstanding is a major cause of public rejection of recycled water. It also has ramifications regarding the public's understanding of the ecological services provided by nature and why they are important.

Discussions of drinking water (and water re-use) often involve the water cycle. A common notion is that water is essentially "immutable" or "old". Journalists and even many scientists have been fond of painting a picture of the water cycle that is grossly over-simplified and incorrect.  At the heart of the matter is the notion that the world's water today is the same water that existed long ago - such as when the dinosaurs roamed!

This mis-portrayal of the water cycle has played an important but hidden role in the reticence of the public in accepting water re-use. The myth of the "constancy" of water - - the purported never-ending recycling of water itself - - is itself a major cause for consumer rejection of water recycling projects. Our traditional concept of the water "cycle" is inherently flawed.

In reality, NEW water is being continually created by myriad biophysicochemical processes. As such, water can be viewed as being constantly "refreshed" or "rejuvenated."  Common examples are the creation of new water (such as from the
numerous oxidative or combustion processes; one visible example is water vapor created by combustion of jet fuel - contrails), and the "destruction" of water (a common exmaple is the hydration of lime that occurs when cement sets). The O-H bonds in water are continually being broken and reformed.

Water is an extremely reactive chemical. Any particular "single" water molecule (composed of the exact same particular atoms of hydrogen and oxygen) is constantyl involved in numerous fast, dynamic processes; note, however, that the notion of a particular "single" molecule is rather elusive to pin down (but this notion is necsssary in order to believe in the notion of  "old" water). These molecules are continually involved not just in continual rearrangement of water clusters and hydrogen bonding (which doesn't necessarily involve bond breakage), but also in autoionization (disocciating to form the hydronium ion H3O+ and the hydroxide ion OH-) and in countless numbers of reactions catalyzed by enzymes, eventually leading to the ubiquitous incorporation of oxygen and hydrogen into the universe of organic molecules(followed by the inevitable release as water).

The bond breakage and formation that continually occurs in water 'clusters' occurs at the pico-second scale. The notion of single, defined "molecules" of water is probably conceptual only - and their existence would be extraordinarily brief.

 This is very important - becuase understanding that water is continually being formed anew serves to better inform the public about perceived risks - an important aspect in oversoming the so-called "yuck factor" that many authors devote considerable discussion to. But it could also serve to show the public one of the values of ecosystems - "rejuvenating" water. This undoubtedly played a major role in the original naming of Singapore's water reuse project (themost dvanced in the world), which produces water that exceeds drinking water standards directly from sewage. Their facility was aptly named NEWater.

 
The risk perception problem (in the case of water reuse) is not
necessarily driven by what's in it, but rather from the mythical
"memory" that water is believed to possess. "Old" water is presumed to possess an ummitbake memnory of its past (such as sewage). Even when ultra-purified resued water can be certified as being much purer than municipal drinking water available from the tap, the fear derives from its past- not its present state.

I have to admit that after 40+ years of studying water (including a large part of the time involved in dating groundwater), I had not thought very much about the 'dinosaur pee" argument. In fact, I  first recall hearing one form of it last fall at the PGWI Conference from Dr. Robert Giegengack (access his presentation at the PGWI site) although he cast it in the form of drinking water that passed through Moses - he proposed that there were 40,000 'Moses molecules' per 8 ounce glass of water. His presentation aslso contains some interesting estimates of the toal number of water molecules.

 To accept the 'dinosaur pee' statement, we must believe two critical elements: 1) the amount of water in the hydrological cycle has remained more or less constant since the time of the dinosaurs (if not longer); and 2) water molecules last forever.

I accept the former but reject the latter. I know that water molecules do not necesssarily last forever. Even in a glass of water at room temperature, some water molecules 'autodissociate' into H+ and OH- (or more accurately, H3O+ and OH-) ions. Water is also 'created' and 'destroyed' by a variety of biogeophysicochemical reactions. And recall that water is H2O and nothing else; when water breaks down into its ionic components, it's not water any longer.  But those ions will eventually recombine back into water, only to dissociate again. So can we consider the water as being 'the same' if the individual molecules have been continually breaking down and reforming?

And just how long does an indvidual water molecule last? I confess to ignorance. A cursory electronic search on the 'lifetime of a water molecule' or 'half-life of a water moelcule' (excluding water molecules comprised of the radioactive form of hydrogen, tritium) yielded no useful results. The thoughtful reader suggest a picosecond scale. Not very long!

My take: So are we drinking dinosaur pee? Yes and no.

No: If you are a 'purist' (poor word choice in this case - maybe 'anal retentive' is preferable) and insist that the water moelcules have to be exactly the same and not have dissociated and reformed many times in the intervening scores of millions of years, then the answer is 'No!"

Yes: If you are easy-going and just require that the H's and O's are the same although they may have dissociated and recombined since the time of the dinosaurs, then the answer is 'Yes!'

By the way, take note of the the final two paragraphs of the responder's message - the connection between 'dinosaur pee' and the 'yuck factor'. Well said.

This has been quite an effort - much ado about nothing?  I think I will get a glass of tap water, then rest.

Note added on 16 August 2011: From NPR - Why Cleaned Wastewater Stays Dirty In Our Minds

"Flush twice; it's a long way to Reno" -- unofficial motto of Truckee, CA (my former home)

Comments

[RT]

Don't miss this morning's NPR story on the psychology (aka "yuck factor") of recycled water: http://www.npr.org/2011/08/16/139642271/why-cleaned-wastewater-stays-dirty-in-our-minds

[David Zetland]

Thanks to those who read drafts of my book:

"Evaporation from this enormous source [oceans] stays in the atmosphere until it precipitates over land to create freshwater flows that join glaciers, lakes, and aquifers; evaporate; or flow back to the sea. Animals and plants also play a role, taking water molecules apart when they grow and creating new water when they respire. This hydrological cycle sustains life, nourishes ecosystems, removes contamination, and moves water from low to high places"