Wonderful question and ...

Wonderful question and answer lies within. Most of us concerned about the quality of well water. One have to understand following things very carefully:

1. Geographical belt of any elements like Ferrous or Arsenic or fluoride. 

2.Well water is very steady. So there is very less change in quality of water except nutritional contamination from external environment. 

3. Understanding chemistry: pH turbidity n conductivity gives idea of range of quality not the change. If any water sample is seasonally monitored, then may change be observed but it is not necessary. 

In well exactly if it is in the belt of toxic elements geographically then it will be possible of containing these elements in ionic form in that water. So there is need of analysis of these parameter. At primary level, one analyses the basic parameters i.e. pH EC turbidity n then Na K NO3^-2 and SO4^-2 Cl- PO4 and then if quality is not balanced ionic , one can opt to do analysis repeat. 

One more thing I would like to mension is that the analysis of heavy /toxic elements in drinking water analysis is costlier than nornal basic parameters as suggested. So, if one is ready to spend some money dor analysis it is possible.any govt and non govt water quality testing laboratories are doing these job..

Have safe drinking water!