ABSTRACT
In Punjab, a northwestern state of India, groundwater is depleting at a fast rate because of its excessive use and mismanagement. Contamination of groundwater and water bodies from geogenic and anthropogenic sources is also becoming a serious problem. Selenium (Se) toxicity is prevalent in 1,000 ha in Hoshiarpur and Nawanshahar districts where about 11 and 4% of groundwater samples were found unfit for drinking and irrigation purposes, respectively. About 9 and 66% groundwater samples of the Ludhiana and Bathinda districts, respectively, had fluoride concentration more than the safe limit of 1 mg l-1. In the Bathinda district, 15-44% of groundwater samples had boron more than the maximum permissible limit of 2 mg l-1. Arsenic concentration in alluvial aquifers of Punjab ranged from 4 to 688 μg l-1, and the majority of them were found unfit for human consumption considering maximum permissible limit of 10 μg l-1. Excessive applications of fertilizers, manures, and agrichemicals to field and vegetable crops lead to nitrate and phosphate leaching and contamination of groundwater and water bodies. In certain situations, nitrates exceed the dangerous level of 10 mg l-1. Industrial effluents, released without any treatment to sewage drains, contain potentially toxic elements in concentrations that are several folds higher than those in domestic sewage water and exceed the maximum permissible limits for their disposal onto agricultural lands. The mean concentrations of Pb, Cr, Cd and Ni in sewage water were, respectively, 21, 133, 700, and 2200 times higher than those in tubewell water. In one study, water of several shallow hand-pumps installed in vicinity of a sewage-water drain had 18, 80, 88, and 210 times higher concentration of Pb,
Cr, Cd and Ni, respectively, than in deep tubewell water. A large number of pathogens were observed in tubewells installed for domestic water supply. Possible remediation options for such deplorable situations are discussed in this article.
