Physicochemical analysis was performed on 32 groundwater samples around the municipal solid waste dump yard, Ariyamangalam, Tiruchirappalli. The dump yard is 12 km from the city dumping that is around 500 tons per day. The parameters such as TDS, turbidity, alkalinity, pH, Mg, NH3, $$ {\text{NO}}_{3}^{ - } $$ , $$ {\text{NO}}_{2}^{ - } $$ , total hardness, Na, K, F, Cl−, SO42−, BOD and COD were tested using standard testing procedures according to IS 3025. The obtained values were compared with BIS 10500. The WQI has been calculated using AW method, and statistical analysis such as variance, standard deviation, correlation, histogram with its distribution and principal component analysis has been performed using SPSS 16.0. The spatial variation of the parameters has been interpolated by using geographical information system as a platform. Using GIS interpolation, the values at the location where the data are not known can be inferred with the known set of values. ArcGIS 9.3 software has been used as an effective tool for the spatial variation mappings. The results suggested the need for adjusting factors managing the solid waste that leads to reduce the leachate contamination of groundwater with repeated monitoring of groundwater quality and leachate percolation.