Publisher:
International Journal Of Advanced Research (IJAR)
Publication Type:
Journal
Publication Title:
IMPACT OF A WASTE DISPOSAL SITE ON GROUNDWATER QUALITY (A CASE STUDY OF OKEODO REFUSE DUMPSITE, IWO OSUN STATE SOUTHWESTERN, NIGERIA).
Publication Authors:
Alagbe O. A , Olutona G.O , Olafisoye E.R, And Olayiwola K.O
Year Published:
2019
Abstract:
Groundwater contamination occurs when urban waste materials, mainly
domestic garbage, are disposed of without the appropriate measures
imposing a high risk to the underground water resources. Groundwater
pollution happens mostly due to percolation of pluvial water and the
infiltration of contaminants through the soil. Due to the dangerous
effect of the pollution on underground water, this work was carried out.
A study of the impact of waste disposal on the groundwater resources
around a refuse dumpsite at Oke-odo, Iwo, Osun state, Nigeria was
carried out using Very Low Frequency Electromagnetic method (VLFEM) and Vertical Electrical Sounding (VES) of the Schlumberger
array. The VLF-EM survey comprised seven profiles with four which
run from East to West with 10m inter-station spacing and another three
from south to the north to cover the entire study area. A total of two
resistivity soundings were also established; one each at the extreme
western and eastern region of the waste disposal site.
Hydrochemical analyses were conducted at the peak of the raining
season and also during the dry season on five water samples from five
hand-dug wells situated at the western and the eastern ends of the study
area. These hand-dug wells have depths ranging from 3 to 5m. Water
samples were tested for the concentration level of NO3
-
, PO4
3-
, As, Fe,
Cu, Pb, SO4
2-
, Zn, and the pH levels.
The results of the VLF-EM and VES revealed the presence of
contaminant plumes which are detected as conductive anomalies
mainly of dissolved salts from decayed organic matters. The geoelectric
section generated from the VES data revealed that the polluted region
has resistivity values as low as 12.0?m and 40.5?m, and very shallow
depths 3.0m and 4.0m to the anomalous source (contaminant plume).
Results of the hydrochemical analyses conducted were compared with
the standard guidelines of the World Health Organization (WHO) to
ascertain their quality and it was shown that the quality of water in the
study area falls below standard.