Water is a highly complex environmental system; its protection cannot be met by traditional methods. As a part of the process, it is mandatory to evaluate the parameters of ground water so as to pursue suitable treatment. These days’ data mining algorithms have been developed to handle various data-rich environmental problems. In data mining, several techniques such as complex non-linear science, soft computing techniques, clustering and association have been applied in the domain of ground water quality assessment and evaluation in and around Coimbatore District. In this work, the statistical cluster analysis methods and association rule mining techniques were used to identify the spatial distribution of different cluster of wells having similar characteristics and determine the relationship between different water quality variables. The water quality assessment in Coimbatore was done using 13 parameters, namely NO3 - , TDS, Mg2+, Ca2+, Na+ , Cl- , F- , SO4 2- , EC, pH and Hardness including location in different sites. The main objective of the present study is to assess the performance of various clustering algorithms of WEKA and identify the most suitable algorithm for clustering water quality samples. K-Mean algorithm and centroid method of Hierarchical clustering performed in the similar manner in clustering. In addition to that, this study focused on identifying the water quality parameters exceeding permissible limits that occur together (TDS, Mg2+, SO4 2- , EC, hardness) in the given samples using Association Algorithms. The performance and efficiency of different association algorithms like Apriori and Frequent Pattern Growth algorithm was evaluated by factors like support, confidence, lift, leverage and conviction values