Evaluation of Ground Water Pollution Potential by Employing the AQUIPRO Method and Verification and Validation of the Method through the Distribution of Nitrate Concentration

The AQUIPRO method was used to assess aquifer vulnerability using the operating water well logs. The AQUIPRO model is a parameter/factor weighting system for rating the pollution potential of aquifers. This method uses the water depth in well, as well as the clay and partial clay thickness in a well, to generate pollution potential scores. In this model, aquifer protection increases as the AQUIPRO vulnerability scores increase and ground water pollution potential decreases. Logs of 30 wells with chemical analyses of nitrate concentrations in these wells were used to determine the ground water pollution potential of Ajabshir Aquifer, East Azerbaijan. Theoretically, low AQUIPRO pollution potential scores should have more frequent occurrences of ground water contamination events than areas with high AQUIPRO scores with similar land-use, well construction, and well densities. The relative AQUIPRO scores were compared with the nitrate concentration in ground water. The results indicated that wells containing more nitrate showed a decrease of AQUIPRO vulnerability scores. The average nitrate-N concentrations within each relative AQUIPRO vulnerability scores category were also compared. The results indicated that as the relative AQUIPRO (R2 = 0.97) vulnerability scores increase, the mean nitrate concentrations also increase. Accordingly, comparison of the AQUIPRO method with the distribution of nitrate, and comparison of average nitrate concentrations in the every classification and relative AQUIPRO vulnerability scores confirmed the accuracy and validity of the method in the region.