An Assessment of Heavy Metals Pollution in the Waters and Sediments of Lake Maninjau, Indonesia

Abstract

Abstract This research performs an analysis of heavy metals in the waters and sediments of Lake Maninjau and the resultant pollution index value. The research was carried out in 11 locations, e.g., floating net cages, endemic fisheries, near settlements, hydropower plants, and seven rivers at the lake’s inlet and outlet at a depth of 0-1.5 metres. Determining the pollution index was conducted based on heavy metals and environmental parameters. Aside from Zn, the concentration of Cd, Hg, Pb, Cu in the waters in all locations exceeded the quality standard. The Hg metal in sediments in all areas exceeded the quality standard of contaminated soil. Concentrations of heavy metals in sediment are higher than that of heavy metals in water. 8 of 11 sampling locations were in the medium polluted category, with the fish cage location having the highest pollution index (PI) value. Anthropogenic activities such as aquaculture, water transportation, and settlements around the lake have an effect on the waters and sediments of the lake, characterised by heavy metal contamination. The lake’s quality must be continuously monitored, and wastewater management improved from activities around the lake to control heavy metal contamination. Further evaluation is required of the heavy metals contamination originating from anthropogenic activities and natural sources.