The Assessment of Freshwater Quality in the Sungai Semantan Based on the Malaysian‘s Index of Freshwater Quality

Abstract

Sungai Semantan is important for fish aquaculture industry in Malaysia. Therefore, the aimed of this article is to assess the index of freshwater quality (WQI) of the Sungai Semantan, Pahang during the rainy season (February to April 2018). The Sungai Semantan WQI was monitored at three stations by assessing six freshwater quality parameters, i.e., DO, BOD, COD, NH3-N, pH, and TSS. The Semantan River’s WQI was assessed using the Malaysian Department of Environment’s WQI classification. The results showed that three freshwater quality parameters, namely DO (6.32 mg/l), COD (46.8 mg/l), and TSS (104.4 mg/l), exceeded the standard at certain stations and classified as Class IV. However, on average, all parameters showed Classes I to III for all stations, and WQI indicated the Semantan River was slightly polluted (WQI 78.2), and classified as Class II. Changes in land use in the Temerloh district for agricultural and urbanisation have exacerbated the Semantan River’s WQI. Contradict to perception that the aquaculture is the main source of freshwater pollution for the Semantan River. Consequently, the Semantan River’s WQI must be monitored regularly, as the river is critical not only for domestic freshwater supply but also for freshwater fish aquaculture and ecotourism.