Characterization of Hydrogeochemical Processes and Fluoride Enrichment in Groundwater of South-Western Punjab

Abstract

The advent of green revolution, increase of industrialization, and fast pace of urbanization and population explosion have induced unplanned abstraction of groundwater for more than 5 decades causing decline in water table. Groundwater is being depleted at a mean rate of $$4.0\pm 1.0$$ cm/year over the Indian states of Rajasthan, Punjab, and Haryana (including Delhi). Groundwater quality is vulnerable to anthropogenic and geogenic sources. Hydrogeochemical processes occurring in an area are generally governed by climatic factors, soil and rock–water interaction, internal mixing, other geochemical processes, and the landuse and landcover practices. The impacts of these processes on groundwater quality can be deciphered using conventional graphical plots, water facies, and saturation indices (estimated using PHREEQC). Several water quality indices were also evaluated to characterize the suitability of water for drinking and irrigation purpose. It was observed that the climatic conditions coupled with rock–water interaction, weathering, and ion exchange are controlling the geochemistry of groundwater in this region. The water table is rising in some regions due to seepages from canal, thus imparting brackish/saline character to groundwater quality and therefore making it unfit for drinking, domestic use, and irrigation. The saturation indices indicate the undersaturation of minerals such as fluorite and gypsum, leading to augmentation of fluoride in groundwater. It is imperative to pay particular attention to practices in areas where aquifers are highly vulnerable to reduce pollution and its impact on public health. This means that proper landuse planning and agricultural practices have to be enforced in the most sensitive areas.