Hi,
We drilled a borewell about 8 months back in Hosur, Tamil Nadu. Water was found at 340ft and the borewell drilled upto 500 ft. The 6" PVC pipe was done for 13-15 feet, as the driller said its all hard earth beneath, rocks from 100 feet onwards so I did not worry too much. We closed the borewell pipe surroundings with the mud powder (that came up during drilling) and left it as it.
Now, after 8 months when I wanted to install a motor, I started cleaning up the surroundings of the borewell casing pipe and found that there is big gap, approximately about 2 inches surrounding the 6" PVC pipe (it looks like as if 8"-10" bore was drilled). This gap seems to go all the way down to the water level, as we could hear sounds of small stones and mud reaching water through this gap.
I have cleaned the surrounding mud for about 2 feet until hard surface was found and covered the gap with gunny bag temporarily. Now, I am worried about how much mud would have reached the borewell bottom, and how to cover the gap as the PVC pipe might also go inside borewell and how to install submersible pump to take out water from the borewell.
(Note: to visualize the gap, one can imagine circle outside a circle)
Kindly advise
Regards