Assessment of the Water Quality and Ecological Health of the Stormwater Management Pond

Abstract

Monitoring of NUST stormwater management pond was conducted in order to assess its quality and ecological health for aquatic life and recreational activities and its use for irrigation. The pond located in the east of campus on the stormwater main Nullah of NUST coming from upstream is a seepage pond, has inlets from stream runoff from upstream of Nullah and nearby adjacent land. Three sampling sites for water quality assessment were selected on the pond site. Grab samples were collected at sampling points over a period of 21 weeks from April to September 2014. All the nutrient samples were collected biweekly. These grab samples were analyzed for pH, Temperature, Turbidity, Conductivity, Total Dissolved Solids (TDS), Dissolved Oxygen (DO), Nitrate and Phosphate. A preliminary investigation of the pond pollutant concentrations and pond ecological characteristics were conducted considering overall average of pond water quality physiochemical parameters. The average concentration of physiochemical parameters in pond water remained within the Ontario Standards and Guidelines for protection of aquatic life recreational purposes and FAO standards for irrigation except water Temperature, Turbidity and Phosphates. Like during hot summer days when ambient temperature was high, the water temperature was also raised above 30°C, Turbidity and Phosphate also raised above than the critical recommended limits of Ontario i.e. 10 NTU and 0.2 mg/L respectively. Overall all good water quality indicators were present and almost all physiochemical parameters fell within the permissible limits of Ontario Standards and Guidelines for the protection of aquatic life and FAO standards and guidelines for irrigation except Temperature in hot and dry days, Turbidity and Phosphates. In this study the NUST pond ecological health found is sensitive to minor changes in physiochemical characteristics of pond water as is typical of urban stormwater pond.