Assessment of Groundwater Vulnerability to Contamination with ASSIGN Index: A Case Study in Haridwar, Uttarakhand, India

Abstract

Groundwater is an indispensable source of drinking water for the survival of mankind. The preservation of aquifers is essential in recent times due to the constant deterioration of groundwater experienced across the globe. Knowledge about regional groundwater contamination and vulnerability is essential in the effective management of groundwater. The present study aims to develop a regional model (ASSIGN) that is a modified DRASTIC model that captures the local variability using field samples to make it more feasible at a local scale. The study is performed in the holy city of Haridwar, India where millions of devotees visit every year and which has become a hub of industrial activities. Three strategies, (1) DRASTIC, (2) ASSIGN, and (3) ASSIGN optimized, were deployed to determine the groundwater vulnerability zone for the study region. The effective groundwater vulnerability model was determined based on the correlation observed with the field values of seven groundwater parameters at 16 site locations. The comparative assessment shows that the ASSIGN optimized model outperforms other models with the highest R2 values. The results obtained from this analysis envisioned that the inclusion of experimentally derived parameters can be an alternative to the classic DRASTIC model with more accurate results. The study highlights the regions and the zones that are under the influence of very high contamination. This will facilitate water planners in effective decision-making concerning the sustainable use of aquifers with minimum groundwater contamination.