RE:The problem. So what I think you're intimating is that the pumping is releasing the pressure to a degree that the copper oxide is being released and jamming the system. The gravity of the 300 ft column isn't sufficient to maintain the pressure.
So they need to either add downward pressure to the column or pump out just enough to start a syphon action. Of course , the syphon action is probably a way too slow a fix so they really need to create some kind of downward pressure on the column.
In any case, there are a myriad of options and combinations to test so it will take time but ultimately it is totallly solvable