The purpose of this study is to assist Taiwan EPA in reviewing the report of environmental impact assessment (EIA) on the section of receiving water quality modeling. Four main tasks are conducted to provide technological support in examining the results of Water Quality Modeling which is used in the assessment of surface water quality. The tasks include: (a) reviewing at least 19 EIA reports, (b) evaluating the performance of the four models (HSPF/BASINS, SWMM, WASP, and Qual2k) which were applied in EIA cases, (c) holding a workshop to discuss Water Quality Modeling, and (d) providing suggestions for revising the guideline of Water Quality Modeling.
In 2014, all of the water quality models (e.g. HSPF/BASINS, SWMM, WASP, Qual2k, and mass balance method) which listed in guideline of Water Quality Modeling are used in project development as EIA report process. Five EIA cases assessed by the complex models (HSPF/BASINS, SWMM, WASP and Qual2k), ten EIA cases used mass balance method and four cases assessed by water quality effluent standard.
The five water quality models (HSPF/BASINS, SWMM, WASP, Qual2k and mass balance method) are evaluated for their capability and applicability to the application of EIA cases. The results indicate that simulation of the four models can obtain comparable results under well fit of the process of calibration and confirmation. The location of water quality data collection also affects the result by using the mass balance method.
Finally, several suggestions might help in the future. This study recommends that government agencies should work with institute (e.g. WERC, Water Environment Research Centre) to revise the modeling guideline or implement models for EIA case applications. Moreover, the institute could play critical role in archiving models and data, maintaining and upgrading them for future applications. The modeling workshop should place frequently to emphasis on modeler education; guideline for model assessment should be developed.