Assessment of nitrate contamination in thanjavur district, Tamilnadu (India)

Groundwater pollution has been reported in many aquifers because of high concentration of nitrate which is the result of excessive use of fertilizers to cropland. Systematic sampling was done, with a view to understand the source of nitrate concentration . 100 sample sites were selected and the samples were taken for a baseline study to understand the geochemistry of the study area and to assess its physicochemical charactertics. The water quality parameters were investigated for pre-monsoon (January 2011) and were compared with the standard values given by ICMR / WHO. The hydrochemical data of 100 samples indicates that the concentration of almost all parameters fall within the permissible limits expert nitrate. Linear Trend Analysis on seasonal basis clearly depicted that nitrate pollution in the study area is increasing significantly. None of the samples during the samples during pre-monsoon season were showing a high concentration of nitrate, exceeding permissible limits of WHO (50 mg /l), which is due to the use of nitrogenous fertilizer in the study area. Appropriate methods for improving the water quality and its management in the affected areas have been suggested.