Nitrate Pollution of Ground Water in Southern and South-Western Haryana, India

Abstract

Abstract With the establishment of direct relationships between concentration of nitrate in drinking water with incidence of methemoglobinemia, which may prove fatal for infants, study of distribution of nitrate in domestic supply has become vitally essential. In southern and south-western Haryana, nitrate levels exceeding 500 mg/l at shallow depths have been observed at several places. In absence of any known geological source of nitrate in the area and non-uniform pattern of distribution of nitrate along the direction of groundwater movement, nitrate pollution is likely to be caused by sewage and agricultural wastes. While some nitrate in water may orginate from fertilisers, major nitrate pollution is likely to be from sewage. Confinment of large number of cattle near wells particularly in hot seasons and uncontrolled discharge of animal wastes is a common practice in the area under study. Concentration of cattle in small areas, coupled with the fact that ruminant animals produce considerable amounts of nitrogeneous organic waste in the area, is damaging manifestation of nitrogen pollution from farm animals. Since coarse textured soils prevelant in the area, have low retention capacity, relatively small amount of rainfall or irrigation water readily moves the leachate from sewage below the root zone. Statistical analysis reveals that there are strong positive correlations between nitrate and chloride at several places where nitrate concentrations are high in ground water. Similarity in the geo-chemical characteristics of nitrate and chloride ions and strong positive correlations between these ions indicate the possibility of nitrate from sewage which is also evidenced by other factors. High concentrations of nitrate in groundwater are health hazard and pollution abatement measures are necessitated to prevent further degradation of groundwater quality.