Abstract:
Soil plays a crucial role in preservation of groundwater resources from
contamination and pollution. In view of this, the study focused on the
geophysical and chemical condition of the Oti landfill soil and also assessed
the physicochemical characteristics of local groundwater and leachate. The
groundwater quality assessment tool was used to assess the impact of the Oti
landfill site on the local groundwater. Systematic, grab and quartering
sampling techniques were used to sample the soil, leachate and groundwater.
On the leachate and groundwater samples, in-situ measurements were made to
record the pH, EC and TDS concentration. Three different pits with depth 150
cm each were dug at the landfill site and three different samples were taken
from each pit at varying depths. Samples were taken to the laboratory under a
temperature below 4OC. Parameters that were analysed included K+, Ca2+,
Mg2+, Na+, Al3+, BOD, COD, DO and some selected heavy metals including
Fe3+, Zn, Cu, Mn, As, Cd, and Pb. Results obtained from the groundwater
samples showed that the water was still in a good condition for usage.
Hydrogeophysical data of the study area was also collected and the DRASTIC
model was used to generate a DRASTIC vulnerability index in assessing how
vulnerable the local groundwater was to pollution and also to validate the
laboratory results. Both the vulnerability and sensitivity analysis results
validated the laboratory results showing that the landfill has had no negative
effect on the local groundwater system.
