This paper is aimed to determine the surface water quality in an around Sylhet City. We used surface water for our keen purpose. Surface water as well as ground water has been contaminated by humans. Nowadays, water pollution is a major global problem which requires ongoing evaluation and revision of water resource policy at all levels. In addition to the acute problems of water pollution in developing countries, developed countries continue to struggle with pollution problems as well. Discharges from various contaminated sources are a very common thing in city life which deteriorates the water quality of any main water source and necessary treatment is required to make water potable. Sylhet, one of the six divisional cities of Bangladesh is suffering from shortage of domestic water supply and adequate sewerage lines, drainage and solid waste disposal problems. This paper will focus on evaluation of the existing condition of surface water in Sylhet City and investigating some physical and chemical quality of water throughout the year 2008 to 2009. The selected parameters for assessing the water quality are pH, total dissolved solid (TDS), biochemical oxygen demand (BOD), dissolved oxygen (DO), ammonia nitrogen, nitrate and turbidity in the vicinity of Sylhet City.

Key words: Ammonia, biochemical oxygen demand (BOD), coliform, dissolved oxygen (DO), treatment, pH.