Water quality status of Sungai Petani River, Kedah, Malaysia

Water is one of crucial natural sources for all livings. However, as the burgeoning population growth and excessive development, the quality of water is deteriorated. Hence, assessing the quality of river water is pivotal not only for determining water quality condition but also identifying polluted areas. This study was conducted to determine water quality status of Sungai Petani River located in Kedah, Malaysia involving three sampling stations (S1, S2 and S3). Six water quality parameters were determined following APHA standard method. The results then assessed following Water Quality Index (WQI) assessment and evaluated based on National Water Quality Standards (NWQS) for Malaysia. Both dry and wet seasons shows increasing index value. In wet season the results were 51.33, 73.06 and 74.76 for S1, S2 and S3 respectively while for dry season index value of 47.97, 58.04 and 69.60 for S1, S2 and S3. Increasing index value from upstream to downstream (S1 to S3) indicates the water quality status was from polluted to slightly polluted (S1 to S3) due to pollutant load from nearby activities. The overall classification for the river water was in class III, the uses for this classification water are water supply with the need for an extensive water treatment and fishery and livestock drinking.