An innovative approach of Drinking Water Quality Index—A case study from Southern Tamil Nadu, India

The aim of the present study is to exhaust the limitations of conventional reputed Water Quality Index (WQI) methodologies through the proposed reliable Drinking Water Quality Indexing (DWQI) system. Slight modifications were carried out in the methodology of the DWQI development which were parameter categorization, development of sub-index with regression statistics and aggregation function with Min–Max operator. Twenty-two water quality parameters were selected for quality evaluation. The proposed DWQI was compared with conventional methodologies of arithmetic DWQI and geometric DWQI and evaluated with a case study. A data set of 24 ground water samples collected from Southern Tamil Nadu, India was made to illustrate the application and feasibility of the index.The results of the case study revealed that arithmetic DWQI scores were higher than the proposed and geometric DWQI while geometric DWQI scores were lower than the proposed DWQI scores. All the indices were well correlated (r ≥ +0.98) with each other. The arithmetic DWQI exhibited significant difference (P < 0.001) with other indices but the proposed DWQI scores had insignificant variations (P = 0.40) with geometric DWQI scores. The comparison of different forms of indices showed that the proposed DWQI was the most reliable indexing system than the others which diminished the sensitivity and eclipsing problems of conventional indexing system.