ABSTRACT

(Received December 30, 1985)

The water pollution levels of Mahaweli River, the longest river in Sri Lanka, the basin of which covers one sixth of the Island, were monitored to probe the impacts of the urban environment in a developing country. It was observed the chemical quality is largely controlled by natural factors. From among the metals however, vanadium, zinc and copper showed higher concentrations. Pb and Cd showed a correlation co-efficient of r = 0.58 for each other, and Co showed a highly significant correlation of r = 0.98 with Cu. The lack of correlation of Pb and Cd with the total dissolved solids (TDS) indicates an anthropogenic input of Pb and Cd into the aquatic environment. In general, the chemical quality of the water in the Mahaweli river is satisfactory for most purposes, none of the major dissolved constituents and nutrients exceeding the limit suggested by the WHO for potable water.