Open refuse dumpsites: effect on soil and underground water in port harcourt metropolis

The microbiological and physico-chemical qualities of five solid waste dumpsites and a control site without dumpsite in Port Harcourt and its environs were determined during wet and dry seasons. The microbiological parameters examined in each sample included, total heterotrophic bacterial count (THB), counts of Salmonella and Shigella, Vibrio cholerae, total and faecal coliform bacteria. Pb, Cu, Mn, NO3-, SO42-, pH and temperature were the physicochemical parameters analyzed. Sieve analysis was carried out to verify the permeability of the soil. The study showed high counts of microorganisms in all the location sampled for soil and water and these were higher than what was obtained from the control samples especially during the dry season. Feacal coliforms were not detected in any of the water samples while Vibrio cholerae was detected only in the soil samples during the two seasons. Total coliforms were high in some locations and within limits in some locations. Cu, Pb, Mn, were detected above the WHO acceptable limits for the well water samples while NO3- and SO42- were within limits for the water samples. Metal concentrations decreased with depth in the soil samples. Permeability is in the order 10-3cm/sec, typical of sandy soil, and implying that with time, there is the possibility of the aquifer being contaminated since their is no layer protecting the leachetes and the underground water. The bacterial genera isolated from the various water and soil samples include the Bacillus, Pseudomonas, Proteus, Enterobacter, Chromobacter, Klebsiella and Serratia. The general results suggest that the borehole water samples were good for drinking and domestic use while the wells which were shallow and open and the soil samples were contaminated due to the dumpsites close to them. This poses a risk to the health of the public within these areas.