HPR
First welcome to the forum sorry for your troubles.
Not sure where the water level is, if it is below the rusted out pipe see if you can get a welder to patch. There is no air movement in the pipe that could be a problem.
The real problem is this, the bad place in the pipe you found could be just the the first of many bad spots.
Before this is all over you may have to do a lot of work, mabey replace the pipe.
Otto
