Stresses over surface water sources in a human dominated environment: A case study in Hamilton canal, Sri Lanka

Purpose: The Hamilton canal in the western province of Sri Lanka is a man-made canal situated in an area with immense anthropogenic pressures. The purpose of this study is to identify the quality variations of the water in Hamilton canal and human perception about the present status of the water of the canal. Design/methodology/approach: Sampling has been carried out in seven locations in the canal during dry and wet periods for water quality analysis. In situ field-testing and laboratory analysis have been conducted for physicochemical, heavy metal, oil and grease analysis of water. Only Pb, Cd, oil and grease were tested in the canal sediments. The samples were analyzed as per the standard methods of the American Public Health Association (APHA) Manual: 20th edition. A semi-structured questionnaire survey has been carried out to assess the human perception on the water of the canal. Findings: The results revealed that average EC, Turbidity, Total Hardness, TDS, F−, Fe2+, Cl−, SO4 2− and PO4 3− of the canal water remained above the threshold limits of inland water standards. Concentrations of Pb and Cd were also above the standards in some locations. Oil and grease were in a very high level in water and sediments. Originality/value: The water of the canal has been affected by nutrient, heavy metal and oil and grease pollution at present. Discharge of domestic, industrial, municipal wastes and sewage are the prominent reasons which have encouraged the deterioration of the quality of water in the canal.