Assessment of Physical-Chemical surface water quality variation across the wetlands of Metropolitan Colombo

Surface water pollution has been increased due to various activities such as urbanization industrialization, agricultural activities and various anthropogenic activities. Standardized limitations in the water quality parameters for irrigation and drinking purposes such as pH, Electrical Conductivity, Calcium, Magnesium, Total Dissolved Solid, Total suspended solid , Alkalinity, Sodium Potassium, Nitrate and DO should be monitored for drinking and irrigation purposes. In order to assess water quality in canals through a large water quality monitoring network , chemical characteristics and pollution amount were assessed in Wetland surface water, to understand actual water quality variation across the wetlands of Metropolitan Colombo Thirty five water quality monitoring locations across the surface drainage network systems were selected and samples were collected.. Based on PCA analysis, two profiles could be identified. Profile 1 consisted in, Variables Positively correlated to axis PC1 and PC2 (BOD, COD. Phosphate, DO, Ammonia, EC, TDS and Salinity). Profile 2 consisted in variables positively correlated to PC1 and negatively correlated to PC2 (TSS and Nitrate.) Water quality of wetlands of Metropolitan Colombo is not in good condition for irrigation purposes; all the studied chemical parameters showed that the water quality at all of the monitoring stations is unsuitable for drinking and irrigation because of the high levels of pollutants.