DTH Drilling - Sediments Not Coming Out

I am using 127 mm DTH Drilling Bit with 4" hammer for water well drilling. The pressure output is 9-10, for water well drilling the formation is s loose formation. The problem are the sediments (small rocks) which are not coming out of the hole. Because of this, I fear that the bit will get locked inside the hole while drilling and will be impossible to bring out easily.  Please see the attached video. Please help me out with this - what should I do?