Proceedings of 3 rd International Conference on Environmental Aspects of Bangladesh [ICEAB 2012]; October 13~14, 2012 23 ID 47 A1-07 Assessment of Spatial Variation of Water Quality of Tunggak River Adjacent to Gebeng Industrial Estate, Malaysia MA Hossain, Sujaul Islam Mir, MA Nasly, ZA Wahid, Edriyana A Aziz Faculty of Civil Engineering and Earth Resources, University Malaysia Pahang, Labuhraya Tun Razak, 26300 Gambang, Kuantan, Pahang, Malaysia; e-mail: ahossain2003@gmail.com ABSTRACT Anthropogenic impact on the Tunggak River is as a result of rapid industrialization in the study area. The study was conducted with the objective to explore the spatial variation of the water quality of the river due to anthropogenic activities. Water samples were collected monthly from selected sites and analyzed applying APHA & HACH standard methods. Trace elements were determined using Inductively Coupled Plasma Mass Spectrophotometer (ICP-MS). SPSS statistical software was used for data analysis. The study revealed that point sources especially industrial wastes contributing the major pollutants. Less amount of dissolved oxygen (DO) and higher concentration of chemical oxygen demand (COD) & ammoniacal nitrogen and trace elements made the water unusable. Based on Department of Environment-Water Quality Index (DOE-WQI) Malaysia, maximum stations except lower and uppermost were categorized as class IV (highly polluted). Pollution was higher in the middle stations due to addition of most of the industrial effluents to those sites. INTRODUCTION Water is the most delicate part of the environment which is essential for human and industrial development. Due to increasing population and rapid growth of industrialization the demand of fresh water rises tremendously in the last few decades [1]. The rate of fresh water deterioration by anthropogenic activities is coupled with the ever- growing demands of water resources [2]. Malaysia is subsidized with bounty of natural water resources which is contributing significantly to the socio- economic development of the country [3]. But the situation is changing day by day with population growth, urbanization and industrialization. According to the Environmental Quality Report 2009, 46% river water of Malaysia is polluted which is higher than previous couple of years [4]. The Tunggak is one of the important rivers in Pahang which is adjacent to Gebeng the main industrial area in Kuantan, Pahang, Malaysia. The town Gebeng is located near Kuantan Port; where industrial development is growing rapidly. These industrial activities are generating effluents which contain high concentrations of conventional and non- conventional pollutants that deteriorating the water quality of the river. In the study area, non-point source associated with runoff from construction sites of newly developing industrial areas and the point source contributing the maximum pollutants especially industrial wastes. Industries like, petrochemical, medicinal, wooden and mining are discharging their effluents in the river through various drain/channels. As a result the water of the river contains high amount of ammoniacal nitrogen (NH3-N), less DO and many other components that deteriorate the water quality. The industrial waste water of the study area contain nickel (Ni), mercury (Hg), cadmium (Cd), zinc (Zn), chromium (Cr), lead (Pb) and copper (Cu) [5]. So, the river water quality becomes more polluted. Therefore, the study was done with a view to identify the behavior of the water quality parameters and to disclose the spatial variation of the pollution status of the surface water. MATERIALS AND METHODS A. Study Area and Selection of Station The Tunggak River is situated in between 3 0 56ʹ06ʹʹ to 3 0 59ʹ 44ʹʹ N and 103 0 22ʹ42ʹʹ to 103 0 24ʹ47ʹʹ E adjacent to the Gebeng industrial town holding several types of industries (Fig. 1). Station selection was done considering the land use-pattern, point-sources of pollution, vegetation and river network. Starting from lower stream 10 stations was selected for sampling. B. Sampling, Data Collection and Analysis Water samples were collected monthly from pre-selected 10 stations. Three (3) samples were collected from identical 3 positions in every station for replication. Data regarding the position of the station was collected using GPS. BOD samples were carried using separate BOD bottle. APHA & HACH standard procedure was followed during sampling and samples preservation [6-7]. Using YSI in-situ data of pH, Temperature, DO, Turbidity, Salinity, Electrical conductivity (EC), and total dissolved solids (TDS) were also collected during the sampling. For chemical parameters HACH spectrophotometer was used. BOD was calculated with the initial reading collected just after sampling and the final reading after 5 days incubating at 20 0 C temperature. TSS analyzed by using gravimetric method and heavy metals were determined by ICP-MS. All parameters were analyzed within 7 days of sample collection. Fig. 1. Map of the study area indicating Tunggak River C. Data Analysis The main aim of environmental research is to identify for underlying factors which are not observable directly in database, for this factor analysis technique is suitable [8]. For the factor analysis SPSS statistical software was used to analyze the data. For this study data were analyzed for mean, standard deviation (SD), range, correlation and Analysis of Variance (ANOVA). RESULTS AND DISCUSSION A. In-situ Parameters River water temperature in Malaysia usually ranges from 24 0 C to 31.3 0 C [9] and Malaysian normal water temperature is 27-31 0 C [10]. Water temperature of the Tunggak river varied