I am writing in response to Lynn Godfrey's letter to the editor about the Tower Well.
Lynn, your letter was well-written and interesting, but could we get a little clarification, please?
You said, Mike Ploughe's report confirms that the Tower Well is drawing water from a "deeper" source. Since it's drilled deeper than other wells in Star Valley, that's self-evident. However, you also said that the water was being drawn from a "different" source, and that needs just a little clarification.
Without a clear-cut explanation, people reading your letter might think that when you said "different" you meant "not from the same water table." Is that what you meant to say? That the water from the Tower Well does not come from the same water table as the rest of the wells in Star Valley?
If you did mean to say that, then has Mike Ploughe found impermeable layers of rock or clay, which separate the deeper water from the rest of the water table? Because, you see, that's the only way that the term "different" can mean "not from the same water table." All prior reports of the strata here show "fractured rock" down to and below the depth of the Tower Well, and so it would appear that it is simply drawing from the bottom of the same old water table.
Also, did Mike mention that it is normal and expected that the deeper water in a water table is older, often much older, than that nearer the surface? Any hydrologist will tell you that, usually, there is little mixing of groundwater, because there is no effective natural phenomenon to drive such mixing. Could you comment on that, please?
And finally, Lynn, was it Mike who said that drawing water off the bottom of the water table would have no effect on the "safe yield" or did you just sort of assume that? Sadly, it isn't true.
Safe yield is tied to recharge rate. For a well to have no effect on safe yield, it has to draw from a different source, meaning a proven aquifer not in contact with the water table.
I'm not taking pot shots at you, Lynn, or trying to nit-pick, but a clear cut understanding of this issue is vital to its resolution.
I look forward to reading your reply.
Tom Garrett, Pine