A 3D WATER QUALITY ASSESSMENT OF RAWAL LAKE, ISLAMABAD

Abstract

Rivers, natural lakes and reservoirs are great assets for developing countries like Pakistan. Water quality of these water systems is being influenced by the contaminated inflows from different sources. To check the water quality, appropriate monitoring is necessary. Rawal lake is a source of fresh water for inhabitants of Rawalpindi and Islamabad. Flows from the upstream of Rawal Lake and its surrounding villages are highly polluted which degrade the water quality of reservoir. So an initiative was taken to determine the water quality of Rawal Lake in 3 dimensions. The purpose of this study was to assess different water quality parameters so that they can be monitored to check the contamination level of Rawal Lake. The water quality can be assessed by finding different parameters like pH, turbidity, dissolved oxygen, temperature, electrical conductivity, phosphate-phosphorus, total nitrogen and total organic carbon as defined by World Health Organization (WHO) and United States Environmental Protection Agency (USEPA). A research plan was developed to allocate the coordinates of the “points of interest” (POI) on the surface as well as at various depths up to 9m of Rawal Lake within the premises of circle of influence having a radius of 300m. Water samples were collected on monthly basis from March to September 2013 consecutively. The data collected was compared with different standards like World Health Organization (WHO) and United States Environmental Protection Agency (USEPA). It was concluded that the considered parameters were within the permissible limits except phosphatephosphorus. The high concentration of phosphate-phosphorus is an alarming situation which enhance the algal growth. This algal growth is the main reason behind the eutrophication which consume the dissolved oxygen. The environmentally worst terrible state of Rawal Lake can only be cured by legitimate lake environmental supervision, watershed management, and execution of environmental legislation.