Comparative study of water quality of rivers used for raw water supply and ex-mining lakes in Perak, Malaysia

Ex-mining lakes are seldom used as sources of raw water for the treatment of public water supply due to the general view that they are highly polluted. This study examined the water quality of these lakes, compared and contrasted them to the water quality of the rivers used for Perak drinking water supply. Ten water samples were analyzed from different ex-mining lakes. Two water samples were from Kinta and Perak rivers. They were analyzed for physico-chemical properties such as temperature, pH, EC, TDS, SO42− COD, Cl− Na+ Fe, As, and Pb. The results showed that temperature varied from 28.1°C to 34.1°C, pH 6.2 to 9.0, EC 55 to 400 μs/cm, turbidity 5.6 to 74.2 NTU, TDS 36.8 to 268mg/l, Cl− 0.483 to 3.339mg/l, SO42− 0.051 to 15.307mg/l, Na 0.669 to 3.668mg/l, Fe 0 to 0.14mg/l, As 0 to 0.004mg/l, and Pb 0.019 to 0.075mg/l. All the samples were highly turbid, had slightly high concentration of Pb, and had common water quality problem. The ex-mining lakes can also be used to supply water after treatment since these rivers are already being used by the Metropolitan Utilities Corporation for water treatment. The ex-mining pools can be used as alternative sources of drinking water supply to the people of Perak.