Assessment of UMS Lake Recent Water Quality and its Suitability for Plant Watering

Abstract

The Universiti Malaysia Sabah (UMS) Lake, located next to Faculty of Science and Technology, is a free water surface constructed wetland that was designed to treat stormwater in the main campus during its construction period in the late 1990s. Frequent treated pipe water supply interruptions in the campus have led to the consideration of UMS Lake as an alternative water supply for plant watering. This study was intended to investigate some recent water quality parameters to provide quick insight into the suitability of UMS Lake water for plant watering. Sampling points, which included the main inlet (S1), other inlets (S2 – S6) and the outlet (S7) were sampled during dry days to reduce interference from on-the-spot precipitation. Each water sample was analysed for its pH, dissolved oxygen (DO), total suspended solids (TSS), 5-day biochemical oxygen demand (BOD₅), chemical oxygen demand (COD) and ammoniacal nitrogen (AN) content using Standard Methods for the Examination of Water and Wastewater as well as the Hach Procedural Manual. The pH, DO, TSS, BOD₅, COD and AN were in the range of 6.4 – 7.1, 3.2 – 7.8, 15 – 65, 0.3 –4.3, 1 – 43 and 0 – 5.2 mg/L, respectively. These results indicate that the water in UMS Lake did not exceed the Class IV Water Quality Index Classification and Use; thus, the water can be used for plant watering in the campus.