EXPERIMENTAL INVESTIGATION OF LEACHATE CONTAMINATION ON GROUNDWATER EXPLORATION IN BASEMENT COMPLEX AREA

Abstract

A total of ten groundwater samples were collected from wells around the site of Orita Aperin refuse dump, Ibadan, Southwest, Nigeria, to determine the extent of groundwater contamination. The results of the hydro-chemical analysis show that groundwater samples collected from wells away from the leachate revealed comparable W.H.O. standard values for groundwater consumption. Most obvious parameters are: increase in total hardness (between 184.8 and 239.6mg/l for samples near the leachate; 74 and 102mg/l for samples far from the leachate), low calcium (ranged from 46.2 to 78.7mg/l for samples near the leachate; 3.7 to 32.8mg/l for samples far from the leachate), magnesium (ranged from 5.1 to 30.3mg/l for samples near the leachate; 3.4 to 21.5mg/l for samples far from the leachate), chloride (between 20 and 224mg/l for samples near the leachate, 32 and 174mg/l), and sulphate content (ranged from 9 to 76mg/l for samples near the leachate; 25 to 38mg/l for samples far from the leachate); while high values of TDS (in samples A and C and I), nitrate (in samples A and C) and chloride (in samples A and I) which were due to the effect of leachate on the water quality resulting to contamination of these wells. Thus, adequate treatment should be carried out on wells located close to the leachate before consumption.