CSSRI has prepared a first approximation of groundwater quality map on 1:6 million scale. Problems of poor water quality are generally associated with arid and the semi-arid regions and in coastal aquifers. 32 to 84 % area under arid and semiarid states is covered under saline/sodic groundwater.
Groundwater Quality in Select States of India
| State | Utilizable ground water resource (M ha-m yr-1) | Use of poor quality waters (M ha-m yr-1) | Area underlain by saline GW (EC > 4 dS m-1) (km2) | 
| Punjab | 1.47 | 0.68 | 3,058 | 
| Haryana | 0.86 | 0.47 | 11,438 | 
| U. P. | 6.31 | 1.42 | 1,362 | 
| Rajasthan | 0.95 | 0.65 | 1,41,036 | 
| Gujarat | 1.56 | 0.26 | 24,300 | 
| Karnataka | 1.24 | 0.17 | 8,804 | 
| Tamil Nadu | 2.02 | NA | 3,300 | 
| All India | 32.63 | NA | 1,93,438 | 



