When you're planning an investigation into the hydrogeologic properties of the bedrock, a common method is to seal off intervals of interest with packers, which are big inflatable rubber donuts that seal against the walls of the borehole, and then do your testing.
(packer illustration from here)
One thing you need to do is find out where the steel casing for the upper portion of the boring ends and where the bedrock begins. Otherwise, you may do a detailed investigation of... a steel casing.
I was relieved to find that the steel casing did not in fact transmit water. The actual bedrock? Still a mystery.