Pollution Research Paper

ASSESSMENT OF GROUNDWATER QUALITY: LEACHABILTY OF THE CONTAMINANTS FROM SOIL NEAR UNLINED DRAIN SITE OF DELHI, INDIA

A. KUMAR, A. RANJAN, K. GULATI, S. THAKUR AND T. JINDAL

Abstract

The identification of proxy indicator for groundwater infiltration of chemical and bacteriological contamination is an important step in managing groundwater resources and hazard assessment. The study explored, physical, chemical and bacteriological analyses of borehole water samples from three different locations of Delhi, named Khyberpass, Mori gate and Delhi gate. All the borehole water samples were collected near drain site from a radial distance of 100-150 meter. The parameters determined included; color, odor, visible particles, pH, temperature, chloride, total hardness, Ca2+ hardness, Mg2+ hardness, electric conductivity, total dissolved solids, turbidity, total alkalinity, dissolved Oxygen, biological oxygen demand chemical oxygen demand, NO3- and NO2- uusing convectional equipments and standard laboratory procedure. Most of these parameters indicated traceable pollution but most of these were below World Health Organization (WHO), water quality standard for drinking purpose. The pH and temperature were ranged between 6.7 to 7.0 and 21.5 oC to 23.0 oC respectively below the standard. However concentration of NO3 - (51.65 mg L-1) in Morigate, dissolved oxygen above 6.0 mg L-1, alkalinity (256.0 mg L-1) in Khyberpass, total dissolved solids above from 500.0 mg L-1, electric conductivity above from 1400.0 μs/cm, Ca2+ hardness above from 75 mg L-1 and chloride (264.0 mg L-1) in Morigate were indicating toxic pollution level in borehole water samples. However, higher contamination was estimated in Mori gate borehole water sample than Delhi gate and Khyberpass. Contamination in water samples indicated unlined drain of nearby location and saturated soil profile from contaminants (naturally occurring ions, CO32-, HCO3 -, and OH- salts of Ca2+, Mg2+, K+, Cl- and Na+) may present possible risk to leach down into the water aquifer. Bacteriological examinations revealed severe pollution in all borehole water samples. Statistical analysis indicated significant difference among most of the parameters tested for in the borehole water samples at 95% level. The effect of such pollution as determined from the study declined away from the polluting source. Therefore, in conclusion, preventing human’s activities to control the sewage discharge directly into environment and entering water body is the key to avoiding bacterial as well as chemical contamination of borehole water.