Kebanyankan projek pembinaan telah dilancarkan di sepanjang Sungai Lebam untuk memenuhi penduduk yang terus tumbuh di Johor Selatan akibat daripada pembangunan bandar dan industri yang deras. Salah satu projek yang biasa dijalankan adalah projek pembinaan kawasan perumahan. Penghasilan sisa mentah yang berpunca daripada projek perumahan tersebut akan memberikan kesan yang ketara terhadap kualiti air di
Sungai Lebam terutamanya pencemaran tahi koliform (FC). Water Quality Simulation Program (WASP7) telah digunakan untuk mensimulasikan kepekatan FC di sungai akibat daripada pelepasan efluen sisa yang berpunca daripada project tersebut. Keadaan pasang surut di Sungai Lebam telah dibina dengan menggunakan Dynamic Estuary Model Hydrodynamics Program (DYNHYD5). Akhirnya, WASP7 dihubungkan dengan DYNHYD5 dalam simulasi. Model in-house yang terdiri darripada I1DISP dan E1DISP digunakan dalam kes ringkas (Uniform Channel) sebelum bermula dengan simulasi kes nyata (Non-uniform Channel). Simulasi kes nyata melibatkan pelepasan effluent sisa di beberapa lokasi sepanjang Sungai Lebam. Kepekatan FC di sungai biasanya dipengaruhi oleh beberapa faktor seperti aras FC, jenis gelombang, arus air dan kesan pencairan. Keputusan kes ringkas menunjukkan bahawa kepekatan FC akan semakin menurun apabila jarak dari lokasi punca pelepasan semakin bertambah. Hal ini disebabkan oleh kesan dilusi. Kajian kes nyata adalah berkaitan dengan pengaruh pasang surut di Sungai Lebam yang terdiri daripada pasang surut anak dan perbani. Takat pencemaran FC adalah lebih ketara pada masa pasang surut perbani kerana aliran air yang lebih rendah berbanding dengan pasang surut anak.
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There are many construction projects that have been launched along Sungai Lebam due to fast urban and industrial development. In order to cater to the ever-growing population in South Johor, one of the solutions is to propose residential area project. Generation of raw sewage due to the proposed residential project would impart significant adverse impact to the existing water quality of the Sungai Lebam especially by faecal coliform (FC) contamination if it is not properly managed. The Water Quality Simulation Program (WASP7) was used to simulate the FC concentration in the river due to the discharged sewage effluent. A hydrodynamic model of Sungai Lebam subjected to tidal effect was developed by using Dynamic Estuary Model
Hydrodynamics Program (DYNHYD5). Eventually, WASP7 was linked to DYNHYD5 in the simulation. In-house models which included I1DISP and E1DISP were used in the simple case study (Uniform Channel) before proceeding to real case simulations (Non-uniform Channel). The real case simulation was studies the effect of discharging the treated sewage effluent in several locations along the river. The FC concentration in the river is affected by several factors such as the FC decay rates, type of tides, flows of water and effect of dilution. Result of simple case study has shown that as the FC concentration quickly dropped to lower values at distances from the discharging location. This is due to the dilution and decay effect as it travels downstream. The study was focused on analyzing the variation of FC concentration due to the tidal effect of Sungai Lebam. There are two type of tides namely spring tide and neap tide. The level of FC contamination is more significant during neap tide as the flow is lower compared to spring tides.
Water quality modeling of faecal coliform in sungai lebam_Tan Chia How_A9_2011_NI