Hi ,

Experts may please suggest the most appropriate methods for groundwater investigations where the water table is below 600 ft , soil comprises of rock formations.

Even though professional advice was sought, 2 out of 5 bores failed. The other three bores also did not yield the expected results. Hence I would like to know  

1. How to get more accurate GW investiagtion over and above the Vertical Electrical Soundings (VES) test results
2. Does National Remote Sensing Agency (NRSA) maps help in getting more accurate results ? 
3. Should we combine two or three methods ( VES + water diviner ) to have a precise result
4. What is the normal success rate (%) in ground water investiagtions