Deciphering surface water quality for irrigation and domestic purposes: A case study in Baitarani Basin, Odisha

The Baitarani River, Odisha, has a strong economic and traditional attachment to the local people. The surrounding community makes use of the river water for the multipurpose of irrigation, domestic water supply, recreation and fish harvesting. The study was conducted to assess the Water Quality Index (WQI) by taking nineteen selected significant parameters from thirteen locations for a period of 10 years i.e., (2008-2018). All selected physicochemical parameters were found under prescribed limits as stated by World Health Organization guidelines except turbidity and DO. The pH values depict slightly alkaline in nature. Further, it is apparent from WQI, that water belongs to excellent to poor category during PRM and MON with WQI values ranging from 17.7 to 59.72 and 17.8 to 58.53 while in case of POM, it falls under excellent to very poor category with values of WQI ranged between 19.25 and 77.69. Maximum WQI values were recorded during POM followed by PRM and MON. The overall WQI values showed good water status indicating suitability for different human uses. The present study points out that turbidity and DO play a central role in affecting the WQI of the river, however, in case of nutrient elements, no such significant roles were observed in affecting the water quality of the river. The visualization of the WQI distributions using GIS software suggests point and non-point source pollution to areas of deteriorating water quality. Sampling station site-8 needs special attention. Ca++ is the most dominant cation with HCO3− as the dominantanion. The abundant of the major is as follows: Ca2+>Na+>Mg2+>K+>Fe2+ which is equal to HCO3− > Cl- > SO42- > NO3- > PO43-. As per piper diagram, all the water samples fall under Ca++-Na+-Mg++-HCO3−-Cl-. Chemical indices like SAR, %Na, RSC, PI, KI and PS were reported and indicate that the surface water in the study area is suitable for irrigation. Correlation between SAR and EC revealed that all sites fall under C2-S1 (medium salinity low sodium) type. Through applying GIS techniques, the spatial distribution of surface water quality analysis reveals that most of the samples comply with drinking and irrigation water quality standards with few exceptions and water needs to be prior treatment before consumption. It can be concluded that depending upon physicochemical parameters, the river requires mitigation measures to control pollutant inflow.