Water from borewell comes with mud

We have a submersible motor for apartment housing for seven families in Chennai. The depth of the bore is more than 100ft. Most of the time the water is turbid. Water should be available at a depth of around 60 ft. 

Any suggestions on what could be the cause for this? And what we can do to find out the issue? 

Can we try lifting the motor up by a few feet and see if that helps to resolve the issue? Please provide some suggestion and alternatives to resolve this.

Thanks, Venkat M