Assessment of Water Quality and Heavy Metals in Labu River, Selangor

Abstract

Freshwater is the necessities for all human beings as this source is used in daily activities. Hence, river water quality needs to be preserved from contaminations for sustainable water management.  Prolong to that; water quality monitoring is crucial to protect the water security and to improve the surrounding environment of water bodies. Here, Langat catchment is an important reservoir for water supply in Hulu Langat District in Selangor, Malaysia. There are two main tributaries of this catchment, which are Semenyih River and Labu River. Here, this paper aims to determine the status of Labu River based on the Water Quality Index (WQI) from the Department of Environment (DOE) and National Water Quality Standard (NWQS) set by the Ministry of Health (MOH), Malaysia. The sampling of water quality was conducted at three stations along the Labu River during October 2018. Several parameters included temperature, pH, dissolved oxygen, conductivity, total suspended solids, total dissolved oxygen, biochemical oxygen demand, ammonia nitrogen, nitrite, nitrate, and heavy metals were determined in this research study. These parameters were analyzed in-situ and in Environmental Laboratory, Faculty of Civil Engineering, Universiti Teknologi MARA. From the results obtained, the water quality index of Labu River can be classified as in-class III, which is between 51.9 to 76.5 (extensive treatment required). Here, the Labu River is considered as slightly polluted as several activities mainly due to industrial, agriculture and wastes from sanitary landfills were observed along the river stretch. Furthermore, the concentration of heavy metals in Labu River such as Iron (Fe) - 1.21 mg/L, Cadmium (Cd) - 0.073 mg/L, Manganese (Mn) - 0.374 mg/L and Lead (Pb) - 0.554 mg/L had exceeded the limit provided in National Water Quality Standard (NWQS) for Malaysia.  From the outcome of the research, necessary treatment is needed to reduce these pollutants as this river is an essential source of water supply in the Hulu Langat District in Selangor, Malaysia. Here, best management practice is required to rehabilitate the river to its natural state.