Letter To:

Mr. Steve P. Martin, Superintendent                                May 12, 2008
Grand Canyon National Park
P.O. Box 129
Grand Canyon, Arizona  86023

Dear Mr. Martin:

 Among other things, I am writing you  to provide you (and your technical staff) some relatively difficult-to-obtain source material related to the levels of  uranium in the Horn Creek spring, a spring that is down slope from the Orphan Mine on the south rim of the Canyon.  If you go to http://public.dirxploration.fastmail.us you will find a down-loadable copy of the University of Nevada-Las Vegas MS geology thesis that Jim Fitzgerald wrote in 1996.  His thesis is the source of the 'high radiation levels' report that the anti-mining activists, especially the Environmental Working Group, have recently been using as justification for pointing condemnatory fingers at northern Arizona uranium mining companies working in the general Grand Canyon area. 

Note that Mr. Fitzgerald relates in his thesis:  (1) That the original main motivation for his research work was the widely felt concern that tourist industry draw-down of the ~2500 foot deep water table would, among other things, dry up the springs coming out of  the Canyon walls (see http://www.gcrg.org/bqr/9-2/wells.htm), and (2) that springs like the Horn Creek spring flow at an extremely low rate (an average of 0.1 gallons per minute at the Horn Creek spring/seep). 

A more recent geochemical study of the springs in the same area conducted by the USGS of your own Department of Interior can be found at http://pubs.usgs.gov/sir/2004/5146/.

The Environmental Working Group recently has begun representing that uranium mining in the area could endanger (see attachments 1 & 2) the Colorado River water supply for those people living downstream of the Grand Canyon.  As the Table below will show you, this is untrue.  Two separate characteristics govern the degree of initial influence any given spring will have on the uranium concentration of the Colorado River river water:  (1) The rate of discharge of the spring, and (2) the uranium content of that water.  The following table was generated using average discharge rates for the springs provided by Fitzgerald (1996) in Appendix III of his thesis, and the average of the spring water uranium concentration determinations provided by both Fitzgerald and the USGS.  This Table, particularly its 4th and 5th columns, shows that seven other springs sampled by the USGS and Fitzgerald are discharging far greater amounts of (1 to 2 magnitudes greater) uranium into the Colorado River drainage area than the two springs -- Salt Creek and Horn Creek -- known to be spatially associated with uranium-mineralized collapse breccia pipes.  It would take about three hundred (300) Horn Creek springs to equal the amount of uranium being daily (and harmlessly) discharged by Hermit Spring into the Colorado River drainage.

Spring	Uranium	Discharge Rate, Q	U Discharge
	Concentration	Gallons per Minute	Productivity
	Parts per Billion		ppb U * GPM
Indian Garden Pump Station	0.21	3740	785.4
Hermit Spring	2.3	314	722.2
Two Trees Spring	1.71	58.3	99.69
Pipe Spring	2.37	27.4	64.94
Monument Spring	7.8	1.3	10.14
Cottonwood Spring	1.4	5.4	7.56
Burro Spring	2.51	1.1	2.76
Salt Spring	26.2	0.1	2.62
Grapevine East Spring	5.08	0.5	2.54
Horn Spring	24.2	0.1	2.42
Hawaii Spring	2.1	0.8	1.68
Lonetree Spring	5.6	0.3	1.68
Page Spring	3.8	0.3	1.14
Santa Maria Spring	6.2	0.1	0.62
Dripping Spring	1.3	0.3	0.39
Sam Magee Spring	3.8	0.1	0.38
Grapevine Spring	1.13	0.1	0.11

High-lighted springs are spatially associated with known mineralized breccia pipes (USGS 2004).

In summary, data collected by Jim Fitzgerald and the USGS both show that springs in immediate proximity to highly uranium-mineralized breccia pipes immediately on the rim of the Grand Canyon are providing insignificant amounts of uranium to the Colorado River drainage because the water uranium concentrations and flow rates of the springs are low.  This is true of the spring closest to the Orphan Mine, the Horn Creek spring. These facts suggest that any future mine development even further from the Grand Canyon rim -- say, into and past the five mile margin thought to be critical by the Environmental Working Group -- should have even less impact on Colorado River water uranium concentrations.  Uranium exploration and mining in northern Arizona pose no threat to the health of the Grand Canyon, and certainly pose no threat to the water supply of 25 million people downstream of the Canyon.

Thanks for your attention.  If I can answer any questions about the data provided you here, please feel free to contact me.

Cordially,

Larry Turner
Managing geologist/president




Below is a letter to Cindy Cole of the Arizona Sun Newspaper sent on 5/16/08 that explains much of the above in layman's terms:

Cindy --

Like I remarked in my phone message to you this morning, I am nearly always working outside of the reach of a digital phone signal, so I am here emailing something of an explanation about what the data table means to me as a geologist/geochemist.  I definitely recommend and request that you run my comments past Dr. Parnell for a double-check.  By the nature of his occupation as an academic scientist, anything he says will be given more credence by general readers.  My words, being those of an applied scientist working for a company interested in finding uranium, are much more apt to be viewed with automatic suspicion by those who don't  know me well.  Keep in mind that with this issue, the thing that should be overwhelmingly important to us all is accurately recognizing what is true, and not saying (or believing) what we just hope or fear is true.

To the data --

The Table I sent you and Superintendent Martin contains two main columns of field measurement that characterize each of the springs in Fitzgerald's thesis and the USGS study -- the year-round average concentration of uranium dissolved in each spring, and the year-round average amount of water (in gallons per minute) coming out of the spring. 

The average amount of uranium dissolved in the water coming out of each spring is expressed in parts per billion by weight ("ppb").  "By weight" refers to the fact that the concentration measurement is expressing the weight proportion of uranium to the total weight of the water and of all the solids dissolved in that water (including, but not limited to, uranium).  For example, a spring like the Horn Creek spring exhibits an average uranium concentration of 24.2 ppb -- this is an average of all the analyses provided by Fitzgerald and the USGS, and reflects the approximate value you could expect to get if you or anyone else went back down to the spring and re-sampled the spring over and over again across any given year.   The spring water uranium concentration value actually shown at any one time will vary from this average, due to seasonal changes in things like the amount of water coming out of the spring and the amount of evaporation taking place at the spring mouth at the time of sampling.  For example, everything else being equal, when more water is passing out of a spring, you'd expect to see a lower than average uranium concentration in that spring water because of dilution by increased amounts of groundwater.  Similarly, when everything else is equal, you'd expect a higher concentration of uranium in water sampled from a small, shallow pool of spring water during the summer time because  evaporation is removing water, but leaving the uranium (and other dissolved solids) behind in the pool water.  Looking at the Table and this column, you'll see that there is some variation in the amount of uranium dissolved in each spring -- some are relatively low, some are moderate, and some are relatively high ('relatively high'  is  not necessarily the same as being harmful or toxic).

The other column of field measurements obtained from work by the USGS and Fitzgerald is the year-round average flow rate of each spring.  This is expressed in gallons per minute and is easy to understand. Some of the springs have a very high flow rate -- like the Indian Garden Pump Station with its year round average 3740 gallons per minute output, while others more or less just barely ooze out of the ground -- like the Horn Creek spring with its year round average output of 1/10 of a gallon per minute.

Now, the Colorado River is below all of these springs, and so you'd expect that any uranium dissolved and then moved to the surface by each spring to eventually work its way down into the river.  The question that many people are worrying about is:  "If uranium mining takes place in the Grand Canyon area, isn't it possible that these springs will start carrying more dissolved uranium, and thus start carrying more, possibly dangerous amounts of uranium down into the river?"  The Fitzgerald and USGS data indicate that this won't happen, fortunately.

First, note that I've provided a column that is labeled 'uranium discharge productivity'.  This was calculated by multiplying the average discharge rate of each spring by the average amount of dissolved uranium in each spring.  This is an indirect measure or index of the amount of uranium that is brought to the surface by the spring and thus can eventually travel by gravity (as a precipitated solid or a dissolved solute) down into the Colorado River.  I could have taken the time to calculate this in more concrete yearly amounts, like grams of uranium per year, but that would take a bit of bother (Dr. Parnell could do this for you, if he has a few minutes).  To better visualize what multiplying uranium concentration in ppb by discharge rate in gallons per minute, think of it as just like multiplying your daily salary by days worked in the week to figure your weekly pay.  Weekly pay ~ ppb U*gallons/per minute -- that is, I've calculated how much uranium is being 'paid' to the Colorado River by each spring in each minute (that's assuming that all the uranium will make its way downhill).

When this is all done for each of the south rim springs studied by both Fitzgerald and the USGS (there is good overlap, but each study looked at a few springs that the other didn't), you find some things that are surprising if you have made the conceptual error of equating high spring water uranium concentration with high impact on the Colorado River.  It turns out that high discharge rate springs like the Indian Garden Pump Station and Hermit Spring with their dilute concentrations of uranium are 'paying' much, much more uranium per minute to the Colorado River than a little oozer like the relatively high uranium concentration Horn Creek spring below the Orphan Mine .  This is because springs like the Salt Creek and Horn Creek ones below known uranium-mineralized breccia pipes are hardly flowing at all -- not much is moving to the surface, and thus not much is being made available to the Colorado River.  The Hermit Spring, as an example, is 'paying' about 300 times more uranium per minute to the Colorado River than is the much-feared Horn Creek spring.  (Note that the ultimate source of the relatively high amounts of uranium in a spring like Hermit Spring is probably ultimately background and anomalous uranium created by/associated with the very ancient mineralization system that filled the region's thousands of breccia pipes with uranium in the first place.)

What is also very interesting is the fact that there is no real difference in the very small amount of uranium being released to the surface by the Horn Creek spring which is below a uranium breccia pipe that has already been opened up during the process of mining (The Orphan Mine), and that very small amount being discharged at Salt Creek spring, which is reportedly (USGS/Fitzgerald) below a uranium-mineralized breccia pipe that hasn't been mined.  This is pretty clear, concrete evidence that future uranium mining even further back from the Colorado River isn't going to disturb things and result in more uranium being washed out into the Colorado River.  In other words, the rock disturbance involved in breccia pipe mining does not appear, in this already conducted 'lab test', to have caused more uranium to be released to the environment.

So, there are three things to be gleaned from the Table data:  1) Uranium is, indeed, being discharged in the Colorado River, but these are small amounts that result in low, non-toxic concentrations in both the springs and the river itself.  2) The springs that appear to be most geochemically influenced by proximity to uranium-mineralized breccia pipes have extremely low flow rates that cause little uranium to be 'paid' to the Colorado River (another things to keep in mind is that low water flow rates through rock tend to heighten the concentration of elements and compounds dissolved in them).  3) High flow rate springs draining this uranium-rich province yield much more uranium to the river, but the concentration of this uranium has already been highly diluted by mixing with the larger volume of water in the main aquifers of the area.

Given the data, then, it seems to me the scientists at the Environmental Working Group  (et al.) who have been alarming people about uranium mining in northern Arizona by projecting negative effects on 25 million people downstream of the Canyon were being pretty careless when they 'pored over' the information that was available to them (and to anyone else interested in the subject).

Hope that helps, Cindy.  Let me know if you have any other questions.  Thanks for your interest and attention.

Larry Turner

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Footnote: Carelessness towards scientific matters by the EWG, is in no way limited to the earth's surface environment -- see http://sukipure.com/quality_skindeep.php for an example of their other blunders.