Abstract:
Open dumping is the most common way of disposing of municipal solid wastes in
developing countries. Municipal solid waste in Matara town is disposed of to an
open dumping site in Kotavila waste management complex (WMC), threatening to
ground water pollution. The study area lacks scientific studies to back claims of
residents on environmental pollution by the WMC. The objectives of this study were
to determine the water quality parameters in the groundwater (pH, Electric
Conductivity, Hardness, Chloride, Sulphate, Nitrate, Dissolved Oxygen, Chemical
Oxygen Demand) and the temporal variation of the above parameter and to prepare
the groundwater quality maps to identify the possible groundwater pollution.
Groundwater samples were collected from wells, natural ponds and paddy fields
(12 sampling points) near WMC. These parameters were measured for 4 months
(November 2019 - February 2020). Water quality maps were prepared using
ArcGIS (10.6 version). The study revealed that the groundwater pH was ranged
between 4.1 to 6.65 and nitrate was ranged between 51.06 mg l-1 to 95 mg l-1, which
exceeded the WHO recommendations. Temporal variations of the parameters were
noted in several months. The spatial distribution reveals that sampling point 7
showed the lowest groundwater level. Further, the water quality parameters
recorded in sampling point 7 were also poor. According to the results of this study,
the measured water quality parameters were within the recommended limit except
for pH and nitrate and observed concentration gradients of chemical parameters
towards the (sample point 7) north direction from the open dumping site. However,
heavy metal contents of well water are essential to be measured to reach a firm
conclusion about water pollution due to open dumping
