What is the maximum depth of water hose in a borewell?

Water hose depth

Our borewell depth is 1000 ft. I dropped a water hose upto the level of 990 feet, and used a 5HP high pressure compressor to pump the water out. Since only 10 feet is remaining to touch the bottom, is there a possibility of silt / mud gathering in jet pipe and blocking it? To avoid this situation how much gap do we need to keep between water hose and bottom of the borewell.

Thanks in advance,