Determination of Water Quality of Rivers under Various Land Use Activities Using Physico-chemical Parameters and Bacterial Populations in Northern Peninsular Malaysia

A study on water quality of rivers with different land use activities by using physico-chemical parameters and bacterial population was conducted around Kedah, Penang and Perak, Malaysia. The water quality parameters such as dissolved oxygen(DO), five-day biochemical oxygen demand(BOD5), chemical oxygen demand(COD), total dissolved solids(TDS), total suspended solids(TSS), nitrate, p H, ammonia-nitrogen, water temperature, water depth and velocity were measured and the densities of bacteria which were total coliform(TC) and fecal coliform(FC) were monitored simultaneously using IDEXX-Colilert?technique from selected rivers. The greatest population of TC and FC(>2 419.6 n MPN/100ml) were recorded from industrial rivers while the lowest reading recorded in less disturbed rivers with less than 1 MPN/100 ml. Total coliform count categorized all rivers into Class I and FC count showed five rivers fell into Class I(Sungai Sedim, Bukit Hijau, Teluk Bahang, Kurau and Tukun), two rivers fell into Class IIA(Sungai Batu Hampar and Salleh) and eight rivers fell into IIB categories(Sungai Jerejak,Pinang, Air Hitam, Kluang, Chelong, Titi Hayun and Cherok Tokun). There was a significant difference between the TC population with TSS content(r=0.43), TDS content(r=0.813), river depth(r=0.513) and DO level(r=-0.401) from all selected rivers.Fecal coliform population was greatly influenced by contents of BOD5(r=0.456), COD(r=0.531), TSS(r=0.813), TDS(r=0.724), and water temperature(r=0.711). The rivers with industrial land-use setting recorded the highest range of water quality index scores and fell into Class III(Sungai Jerejak, Air Hitam and Kluang) and Class V(Sungai Pinang). Both plantation rivers(Sungai Chelong and Sungai Salleh) fell into Class II and all recreational and less disturbed rivers fell into Class I.