RESUMEN
While the contribution of industrial parks to the socio-economic aspect has been widely acknowledged over the past two decades in Vietnam, the problem of environmental pollution due to the wastes generated from industrial parks, especially wastewater, has still been an emerging issue, which places a great pressure on the Government. The wastewater generation from industrial parks was ordinarily required to report in all environmental impact assessment (EIA) reports as a base for the construction of on-site wastewater treatment plants within the industrial park. In Vietnam, this data was, however, often higher than the actual generated number due to inaccurate technical guidelines on predicting wastewater generation and many different methods to be applied. This study aimed to evaluate different approaches used to calculate the effluent in the industrial parks. The results showed that all of the four approaches (i.e., previous operation-based, water-based, wastewater-based, or experience-based methods) rendered significant gaps between predicted and actual values. None can be acceptable for use at present. A revision of technical guideline should be conducted to provide more detailed instruction for the better prediction. This shall minimize the investment capital and increase the efficiency of industrial parks in pollution control.