Need advice regarding borewell installation and its expected life in Tumkur, Karnataka

We want to install a borewell in Tumkur town (70 kms from bangalore). We already have a borewell (dug upto 400 feet) which has dried up (within 3 years). Now geologist says that just 80 feet from original bore , there is a water source at 650 feet. Borewell driller person says that inserting a iron pipe for 150 feet is what they do, though they drill until they hit the water source (~ 700 or 800 feet).

On the other hand, in Tamilnadu (Cauvery delta region - Thanjavur), borewells are installed even upto 400 feet or more. they are working for more than 10 years now without problem. they use PVC pipe.

In TN, I learnt that borewell drillers use PVC pipes (pipes with cuts along its length) and encased in another outer pipe. Moreover it seems they use jally packing. These steps are told to help filtering water so that the bored area does not get covered over time.
In Tumkur, when we enquired borewell drillers say that Tumkur is silt area and hence borewell anyway won't last long and they don't use such techniques.

Can someone help me with this problem?
is it not possible to do a borewell which will last for atleast 10 years in tumkur? what kind of borewell should be done?

Ponni K