Ewest -- that is the 60 million dollar question. As you know, our groundwater pits are by far the most likely to resist winterkill. I don't know if there is some amount of oxgyen at the upper limit of the ground water? Or, could it just be the movement that allows some oxygen to become mixed at the upper limit? I just don't know. We sure see the results, and having Dwight verify these things long-term has been great for all of us.
