Numerical model for pollutant dispersion in the Dumai estuary

The development of industry and the urban population in Dumai city potentially increases the amount of domestic sewage into the Dumai River, which is gradually deposited in the Dumai estuary. This condition has an impact on the environment and public health because of the higher concentration of pollutants. Knowing the dispersion of pollutants is very important in order to manage and monitor the water quality in the Dumai estuary. This research simulated a numerical model that was developed using MIKE 2’ to study pollutant dispersion in the Dumai estuary as an impact of domestic sewage from Dumai city. Three important parameters of pollutants were discussed in this study, such as ammonia, nitrates and nitrites. The data used for modeling included winds, tides, bathymetry, and the pollutant concentration. The result of the numerical simulations shows that the concentration of all pollutant parameters tends to increase in the Dumai estuary. The concentration of ammonia, nitrates, and nitrites increase to 0.4 mg/L, 0.15 mg/L, and 0.14 mg/L respectively. Those concentrations exceed the standard maximum value that has been appointed by Indonesian regulations. It means the domestic sewage from Dumai city should be treated before it is discharged into the river