Abstract:
Groundwater represents 97% of global freshwater and is an important source of water for
agriculture and industrial activities worldwide. This valuable resource is increasingly
being threatened due to increase in human population and anthropogenic influences.
Industrialization has also become a major threat to groundwater quality worldwide due to
contamination of water with industrial effluents. This study was conducted with the
objective of evaluating the effect of industries on the groundwater quality in selected
locations in Gampaha district.
Water from 40 shallow wells located in close proximity to industries and 20 shallow wells
located in non-industrial areas in Katana, Mahara, Biyagama, Wattala and Ja-Ela were
collected from November, 2016 to December, 2016. Industrial effluents discharged from
10 industries located in the industrial area were also collected separately for the analysis.
The collected industrial wastewater and well water samples were analyzed for pH,
Temperature, Turbidity, Electrical Conductivity (EC), Total Suspended Solids (TSS),
Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD5) and Oil & grease. The
water quality data of well water collected in industrialized areas and non-industrialized
areas were compared using the student t test.
Turbidity and EC values of wastewater samples collected from Wattala area exceeded the
permissible limits of effluent discharge standards for inland waters of Sri Lanka. COD and
BOD5 levels recorded in wastewater collected from Ja-Ela area also exceeded the
permissible limits of wastewater discharge standards. EC, COD and turbidity values
recorded in almost all the shallow wells located near industrial areas exceeded the
permissible limit of SLS drinking water quality standards. The results of the present study
suggested that EC and turbidity values in shallow well water in industrialized areas are
having a close association with the industrial activities. Findings of the present study
suggest the need of proper industrial waste water discharge mechanisms in order to
improve groundwater quality of the area. Further studies are also required to evaluate the
effects of the seasonal variations on groundwater quality.
