Radon fan with submersible pump. Is this normal?
That thing is called a sump pump.  It has nothing to do with your radon or your heat pump.   It has one purpose, removing groundwater from your basement.   Without it, your basement may eventually flood. 

The water at the bottom of the sump is normal. This is what primes the pump.  Many pumps rely on hydraulic lock (the incompressibility of water) to function aka to "prime"... And also need the water as a coolant and lubricant.  So don't be surprised when you find a pump that Does Not Like running dry.