In this study, methods using LDC (Load Duration Curve) and watershed model were suggested to develope management targets and evaluate target achievement for non-point source pollution management considering watershed and runoff characteristics and possibility for achievement of target. These methods were applied for Saemangeum watershed which was designated as nonpoint source pollution management area recently. Flow duration interval of 5 to 40% was selected as flow range for management considering runoff characteristics and TP was selected as indicator for management. Management targets were developed based on scenarios for non-point source pollutant reduction of management priority areas using LDC method and HSPF model which was calibrated using 4 years data (2009~2012). In the scenario of LID, road sweeping and 50% reduction in CSOs and untreated sewage at Jeonju A20 and 30% reduction in fertilizer and 50% in livestock NPS at Mankyung C03, Dongjin A14 and KobuA14, management targets for Mangyung bridge, Dongjin bridge, Jeonju stream and Gunpo bridge were developed as TP 0.38, 0.18, 0.64 and 0.16 mg/L respectively. When TP loads at the target stations were assumed to have been reduced by a certain percentage (10%), management targets for those target stations were developed as TP 0.35, 0.17, 0.60 and 0.15 mg/L respectively. The result of this study is expected to be used as reference material for management master plan, implementation plan and implementation assessment for non-point source management area.

a b s t r a c tConstructed wetlands (CWs) are artificially engineered ecosystems designed and developed to manipulate the biological processes within a semi-controlled natural environment. CWs were beneficial for having uncomplicated operation and maintenance activities, providing a wildlife habitat in urban and suburban areas and an aesthetic value within the local environment. However, there were current limitations on the CWs operations such as few design guidelines, limited performance results regarding the pollutant attenuation and the absence of long-term comprehensive mass balance analysis. The objective of this research was to analyze the reduction performance of various CWs with regard to the respective monitoring data and develop the necessary design guidelines based on the similar trends analyzed from the mentioned CWs. The formulated design guideline would be suitable for CWs treating various wastewaters. In order to develop the design guideline, various CWs in Korea and other countries were investigated with respect to three scenarios namely site survey, water quality and ecosystem monitoring and performance reports. Based on the results, using the CW design characteristics (i.e., surface area, catchment area, etc.) and pollutant reduction capabilities (i.e., pollutant removal efficiency, HRT, vegetation coverage, etc.) the derivation of the formula needed to calculate the appropriate CW size, forebay size, vegetation coverage was developed. For the cost-effectiveness of the CW, the economic feasibility of the investigated CWs was evaluated with respect to the CW formation costs and was compared with the particulate removal efficiency.

In this study, the applicability of dynamic water quality model to TMDL system was examined, methods for setting of water quality goal and estimation of allocation loads were suggested and results of applying these methods were analyzed. HSPF model was applied for Miho stream basin as a dynamic water quality model. The model was calibrated using measurement data obtained in 2009~2010 and showed satisfactory performance in predicting daily variations of flow rate and BOD concentration. Methods for TMDL application were categorized into 3 cases; water quality management (1) considering low flow condition(Case I), (2) considering entire period of the year (Case II) and (3) considering the worst water quality condition (Case III). BOD water quality goals at the end of Miho stream watershed increased in the order of Case IICase I>Case III. If further researches on base precipitation and method for model input of nonpoint source pollutant were carried out, water quality could be managed more reasonably and scientifically by applying dynamic water quality model to TMDL. The result of this study is expected to be used as primary data for TMDL using dynamic water quality model.

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