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Performance evaluation of nonpoint source pollution management facilities prior to installation on site can provide consumers with guidelines on the ability of pollution removal and maintenance cost of facilities. Various test methods for demonstrating the performance of nonpoint source pollution management facilities exist, but in the case of standard test water for indoor testing, it is necessary to develop a test water manufacturing method that takes into account the characteristics of the stormwater runoff. In this study, we investigated and analyzed the particulate matter of the stormwater runoff flowing into the nonpoint source pollution management facility. Differences according to land use characteristics were analyzed for particle size, specific gravity, and organic matter content. Based on these findings, standards for manufacturing simulated stormwater were presented. The results showed that it is reasonable to simulate the particle size within a maximum of 190 µm, and specific gravity and organic matter content differed depending on the characteristics of land use. Although the results of this study were applied in Korea, this method can be applied in a variety of countries because it presents a method for selecting the criteria for soils required for manufacturing stormwater when evaluating nonpoint source pollution management facilities. [ABSTRACT FROM AUTHOR]

The increase in impervious areas caused by urbanization causes the amount of surface rainfall-runoff and nonpoint source (NPS) pollutant discharge to also increase. This issue has sparked a growing interest in low impact development (LID) technology and NPS reduction technology. The objective of this study is to analyze the ability of a hybrid system to achieve both rainfall-runoff and NPS pollutant reduction simultaneously. The results indicate that this system is effective in reducing particulate matter with a relatively small particle size (less than 64 µm), which plays an important role in reducing NPS pollution. It is expected that a LID-based urban water cycle recovery policy could be established through further research on various hybrid system configuration methods and socioeconomic effect analysis. [ABSTRACT FROM AUTHOR]

This paper describes the effects of weir construction on water quality in the Yeongsan (YS) River. In general, weirs affect aquatic environments of rivers and streams by interrupting natural water flow. To identify changes in water quality before and after weir construction, analysis of variance and autocorrelation tests were conducted on data from four monitoring stations. Seasonal variations in suspended solids (SS), biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and pH were analyzed using data from six years of monitoring. No significant changes in mean BOD5 or COD followed the construction of weirs. However, mean TN and TP were changed significantly during and after construction. Moreover, SS and pH changed significantly during construction, and TN and TP concentrations were slightly improved after weir construction. However, continuous monitoring and analysis of water quality changes in each weir are required to prevent environmental disasters such as algal blooms. [ABSTRACT FROM AUTHOR]

To manage and control the nonpoint source (NPS) pollution and to improve the water quality of impaired streams, rivers and lakes, practices including constructed wetlands, permeable pavement, swales and others are being attempted in the world. Before applying these techniques, an analysis of stormwater runoff characteristics should be understood due to the complexity in estimating system design factors for best management practices (BMPs). This study investigates the stormwater discharge from an agricultural area in Korea. Based on this investigation, pollutant and fl ow coeffi cient of variation (PFCoV) values were developed in an attempt to explain the stormwater runoff in the agricultural area. Four fi eld studies categorized by rainfall type were then employed to assess the PFCoV values. The results show that the physical meaning of PFCoV values indicates the variation of NPS pollutants during a storm event. As such, this simple and meaningful result can be applied to a wide range of stormwater management designs or water quality controls in agricultural areas. [ABSTRACT FROM AUTHOR]

Nonpoint source (NPS) pollution is widely recognized as a major source affecting the water quality deterioration in rivers, lakes, and marine environments. Many studies about the relations between NPS pollutants and solid matters from drainage area have been carried out in the area of stormwater management. This study collected stormwater and soil samples from a drainage area in Korea; the particle size distributions (PSDs) were then analyzed during four storm events. The results indicate that the PSDs of fine and medium silt in the stormwater are related to the soil component of the drainage area. In addition, solid matter was strongly related to NPS pollutant discharges such as total nitrogen and total phosphorus during stormwater runoff. Therefore, to design an NPS management facility, the PSD from the drainage area should be considered. It is expected that this study can be applied to the designs of settling ponds used to remove particles from stormwater runoff. [ABSTRACT FROM AUTHOR]

Advanced total phosphorus (TP) removal is required to regulate the TP concentrations to less than 0.2 mg/L, as specified by the South Korean policies for the prevention of aquatic eutrophication. In order to meet the standards from 2012, the treatment efficiency of conventional treatment plants should be improved. This study addresses this need by developing a novel TP removal methodology that uses a static mixer for coagulation and a redesigned sedimentation tank incorporated with a guiding baffle. Experiments were carried out during summer, autumn, and winter. Results show that: (1) the phosphorus removal efficiency was relatively higher in summer than in autumn and winter, (2) the inline static mixer increased the efficiency of soluble phosphorus removal to above 95%, and (3) optimal angle determination for the guiding baffle was essential to achieve a stable hydraulic behavior and a low shear rate at the bottom of the sedimentation tank and thus to improve the sedimentation rate. In addition, the application of combined sewer overflows sludge led to stable and high phosphorus removal efficiency (> 90%). These results indicate that the newly designed TP removal plant could serve as a prototype for an advanced treatment of phosphorus in wastewaters. [ABSTRACT FROM AUTHOR]