Determination of water quality index and heavy metals of an ex-mining lake, Kg Gajah, Perak / Shamsilawati Mustafar

This study was carried out at ex-mining lake in Kg.Gajah, Perak. The study covered the measurement of the Water Quality Index (WQI), determination of heavy metals and essential in water of ex-mining lake and compare water quality index with Malaysia Water Quality Index from DOE. Ex-mining lake of Kg.Gajah, Perak was preferred as the area of study because this lake is one of the largest ex-mining areas in Perak. This area was used as the land for mining activities. There were ten different points where water samples were collected. Parameters that are used to calculate WQI are pH, DO, COD, BOD, AN and SS. AAS was used to determine the concentration of heavy metals in the various points of water samples. The results are evidence for that WQI for this ex-mining lake is 66.1, which meant it was in class III based on DOE water quality standard for Malaysia. According to DOE, class III of Water Quality Index showed that water need extensive treatment before it was used as water supply