Will you be drilling and blasting the drifts or tunnels or will you be driving them with a tunnel bore machine?
The difference is that blasting can and will cause the ground around the drift to fracture for 1500 ft in all directions, thus opening an avenue for ground water to enter the storage area.
Also have you done any diamond drilling in the creighton area yet and could you send me a map of the holes you have drilled or that you will be drilling?
Also a map of the location of the site.
Have you done studies on the prevailing wind direction in that area and found out if there are communities that would be affected by a spill on site?