Borewell 325 ft, piping upto 300 ft, casing 45 ft - getting muddy water after 1 min and again getting clean water after 10 mins - Please help with a solution

Dear Sir/Madam,

I am from Bangalore, Karnataka. I have a borewell of 325 ft depth, with a submersible pump, which  has a piping upto 300ft and casing upto 45ft . I have been using this borewell for more than 10 years.   For last 5 days, when pumped there is clean water for less than 1  min after which the water turns muddy. After 7-10 min the water turns almost clean again. Please guide me.

Suresh P
mob: 9980510855