The Level-I Laboratories are located at 258 field water quality monitoring stations on various rivers of India where physical parameters such as temperature, colour, odour, specific conductivity, total dissolved solids, pH and dissolved oxygen of river water are observed. There are 24 Level-II laboratories located at selected Division Offices to analyse 25 physico-chemical characteristics and bacteriological parameters of river water. Four Level-III/II+ laboratories are functioning at Varanasi, Delhi, Hyderabad and Coimbatore where 41 parameters including heavy metals/toxic parameters and pesticides are being analyzed.

While there are differences between the rivers, for any one river also the chemical composition may vary at different times (monsoon/non-monsoon), across years and at different places since water quality is highly susceptible to spatial and temporal variability. Some points emerging from a look at the data for some of the Indian rivers are –

• Brahamputra & Barak Basin: On Brahmaputra River, Level-II Divisional Laboratory, MB Division, CWC, Guwahati, site at Pancharatna; this baseline station monitors 23 parameters on a quarterly basis.
• Barak Basin: On Barak River, Upper Brahamputra Division Water Quality Lab Level-II Dibrugarh; site at Dibrugarh; this trend station monitors 15 parameters on a monthly basis.
• Meghna Basin (Assam):  On Barak River, Level II Laboratory , MBD Division, CWC, Guwahati; site at AP Ghat; this baseline station monitors 24 parameters once in three months.
• Indus Basin (J&K): On Chenab River; Level II Laboratory, Chenab Division, CWC, Jammu; site at Benzwar; this trend station monitors 24 parameters on a monthly basis.
• Ulhas Basin West Flowing River (Maharashtra): On River Ulhas, Level II Laboratory, Upper Krishna Division, Pune; site at Badlapur; this trend station monitors 30 parameters on a monthly basis.

The reports can be downloaded below -