Effect of Waste Dumps on Groundwater in Choba using Geophysical Method

The aim of this work is to investigate the effect of waste dumps on the groundwater in Choba using resistivity sounding method and laboratory water sample analysis. An ABEM SAS 1000 terrameter was used to acquire data in two locations namely; at the dumpsite and at University Demonstration Secondary School adjudged to be free from dumps which served as a control. The result of the survey interpreted by 1P12 win and offix softwares shows two characteristic curve types: Type A curve at the dumpsite and Type H curve at the University Demonstration Secondary School. The result further indicates that the first two layers at the dumpsite has resistivities of 59.91 and 20.10 ohm.m respectively and at the Demonstration Secondary school as 173.00 and 512.00 ohm.m respectively, showing that the groundwater at the dumpsite is polluted because of the high conductivity . This was confirmed by the laboratory water sample analysis from the environ. However, fresh uncontaminated water is got below 23m deep at the two sites. Niger Delta has multi aquifer systems, therefore geophysical survey is essential to locate at least the depth to the third aquifer which hopefully will give portable drinking water free of contamination. @ JASEM Choba community is located along the East-West road and lies between latitudes 431 ́ and 500 ́N and longitudes 645 ́ and 730 ́E in the South South Nigeria. Some component of these wastes including food, paper etc consume oxygen thereby changing the redox potential of the liquid present. Percolating groundwater provides a medium through which wastes particularly organics can undergo degradation into simpler substances through biochemical reactions involving dissolution, hydrolysis, oxidation and reduction processes. This leachate, the liquid drains from the dump, mainly organic carbon largely in the form of fulvic acids (Taylor and Allen, 2001) migrate downward and contaminate the groundwater. Each year about two million people die as a result of poor sanitation and contaminated water, ninety percent (90%) of the victims are children (Anon, 2009). Various workers have studied the effect of solid wastes on the groundwater in Port Harcourt and its environs. Udom and Esu (2004) carried out a preliminary assessment of the impact of solid wastes on soil and groundwater in Port Harcourt city and it’s environ and concluded that the groundwater is contaminated. Udom et al (1999) studied the Hydrogeochemistry of groundwater in part of Port Harcourt and Tai Eleme Local Government Areas and discovered that the groundwater in the Benin Formation is soft and low in dissolved constituents except pH and iron with mean values of 6.01 mg/l and 0.36 mg/l respectively. Akpokodje (1999) noted that a staggering amount of solid waste is generated in the Port Harcourt metropolis each year. Fig. 1: Map of Choba showing the study area UDSS