So I went back in time using Google Earth, and the last clear image was on June 1, 1994, and the three (3) tanks were present. Now, I have no idea if they were being used for MMA at that time. But the three (3) tanks were present, along with the larger tank next to them. I cannot be certain, but the water deluge system is not obvious in the earlier images and becomes crystal clear in March of 2011. Granted, the images between 2002 and 2011 are not the best images, but it does not appear there is a deluge system before 2011.