• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.547-556
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• 2005

The objective of this study is to obtain adequate intercepting flow during wet weather conditions in combined sewer system. Two study sites are selected under considering different population density, one is developed area with heavy urbanization. Another is recently developing area. In the analysis of field investigation, SS was most significant in initial flushing effects compared with other factors and showed the result with the order of COD, TP, TN. As compared with event mean concentration(EMC) of runoff, BOD, TN and TP showed high concentrations in wide area with relatively large population density. It is by the reason that much pollution load was discharged to receiving water from urbanized area during wet period. According to results of storm-water modeling, 53% of total COD and 52% of total SS pollution load were discharged to receiving water by overflow than intercepting capacity in middle population density site. Also, in the urbanized area, pollution load was discharged to receiving water by 49% of total COD and 77% of total SS. These results can be applied to setup for pollution load flow(budget) generation, collection, treatment and discharging in order to obtain adequate intercepting flow.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.557-564
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• 2005

The objective of this study is to evaluate a criteria of intercepting capacity and a reduction goal of overflow pollution load in combined sewer system. In the current criteria of intercepting capacity in the domestic sewage facility standard, it is known that three times of peak sewage (Q) in dry period or runoff flow by 2mm/hr is not appropriate since the intercepted flow is estimated by runoff and show different result even in the same watershed. Though a reduction goal of overflow pollution load can be determined from 1) same level of storm-water runoff pollution load in separated storm sewer, 2) less than 5% sewage load in dry weather period, by the domestic sewage facility standard, the simulated results from storm-water model show large differences between two criteria. While it is predicted that sewage pollution load standard three time larger than separated storm sewer standard in high population density and urbanized area, it is shown that separate storm sewer standard larger than sewage pollution load standard in middle population density and developing area. Accordingly, it is proposed that more reasonable intercepting flow and reduction goal of overflows pollution load should be established to minimize discharging pollution load in combined sewer systems. For the purpose, a resonable standard has to be amended by pollution load balance considering the characteristics of a watershed for generation, collection, treatment, and discharging flow.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.1-10
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• 2016

In this paper, an analysis of the inflowing pollution load of the rivers in Hampyeong bay showed the average organic matter pollution loads of BOD, COD, and TOC to be 79.7 kg-BOD/day, 144.06 kg-COD/day, and 93.0 kg-TOC/day, respectively. The inflowing organic matter pollution load was the heaviest in Sonbul dike, followed by Jupo bridge and Yangman complex. With regard to season, the load characteristics were outstanding in July, the rainy period in the summer. The average inflowing pollution loads of nutrients were 20.9 kg-DIN/day, 17.1 kg-DIP/day, 148 kg-TN/day, and 37.4 kg-TP/day A comparison of the inflowing nutrients loads for each river showed the load to be the heaviest in Yangman complex, followed by Baegok bridge and Jupo bridge. In the experiment on the material budgets of Hampyeong bridge conducted using a box model, the detention time of fresh water was found to be 52.4 days, with the bay displaying the characteristics of a so dissolved inorganic nitrogen (DIN) in the nutrients material budgets, ${\Delta}DIN$ values were found to be negative, indicating the tendency of consumption and open sea leak by photosynthesis to be higher than the nitrogen that flowed in. As for dissolved inorganic phosphorus (DIP), ${\Delta}DIP$ showed positive values, indicating a tendency for accumulation as the supply through organic matter decomposition, elution load of sediments, and inflowing load of the river turned out to be higher than the consumption by phytoplankton and outflow to open sea.

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.347-355
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• 2012

In this study, non-point pollution sources in the Yeongsan river basin are analyzed; then, the priority regions (areas divided on a small scale) of management are selected for efficient water management of the Seungcheon and Jooksan reservoirs, which were constructed as one of the 4 major rivers restoration projects. The priority regions are decided by using the criteria of the excessive rate of target water quality, non-point pollution load per unit area, total TP load and down flow distance. The results of this study are as follows. The upper 10% of the priority regions for non-point pollution management includes YB15, YB05, YB10, YB24, YB14 and YB11 for the Seungcheon reservoir watershed, and YC24, YC25, YC30, YC34, YC22 and YC17 for the Jooksan reservoir watershed. However, a few regions in each of the Seungcheon and Jooksan reservoirs need to be selected in higher order, and the non-point pollution removal facilities in the regions need to be installed with respect to budget, urgent matter, and so on.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.1
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• pp.61-73
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• 2021

Recently, the deterioration of water quality in Wonju stream has been reported due to the increase in diverse pollution sources along with community development and urbanization. Various types of attempts with a huge budget were made for better water quality so far, but its effectiveness is still doubted. In order to establish site-oriented measures for water quality improvement, the topographic and hydrologic factors were evaluated based on site inspection and survey. As the major streams merged into the Wonju stream, the Hwa and Heungyang streams were found to have higher pollution loads and contributions compared to other streams due to the scattered livestock farms and industries, and vulnerable land use. Notably, the discharge water from the Wonju Public Sewage Treatment Plant had the highest level of pollution load, impacting on the water quality of Wonju Stream. According to the SWAT model as water quality measures, the improvement effect of water quality in this treatment plant can be reached to the reductions in BOD 11.06%, T-N 23.56%, T-P 10.60% when the proper managements applied, whereas the improvement of water quality would be 3.89%, 1.23%, and 3.32% for BOD, T-N, T-P, respectively, for the industries. The reduction of the livestock industry was generally very high as a pollution source, but it was not much higher at the end of Wonju Stream than other measures. These results recommended that the water q uality improvement measures should be designated for each upper-middle-lower section in Wonju stream.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.481-493
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• 2009

This study was conducted to performance appraisal of Total Maximum Daily Loads (TMDLs), especially in terms of performance on development & reduction plan and water quality status of unit watershed. Because load allocations for pollution sources were predicted redundantly by uncertainty of prediction, TMDLs master plan has been frequently changed to acquire load allocation for local development. Therefore, It need to be developed more resonable prediction techniques of water pollution sources to preventing the frequent change. It is suggested that the reduction amount have to be distributed properly during the planning period. In other words, it has not to be concentrated on the specific year (especially final year of the planning period). The reason why, if the reduction amount concentrate on the final year of the planning period, allotment loading amount could not be achieved in some cases (e.g., insufficiency of budget, extension of construction duration). If the development plan was developed including uncertain developments, it is necessary to be developed reduction plan considered with them. However, some of the plans in the reduction plan could not be accomplished in some case. Because, it is not considered financial abilities of local governments. Consequently, development plan must be accomplished to avoid uncertain developments, and to consider financial assistance to support the implementation of effective plan. Water quality has been improved in many unit watersheds due to the TMDLs, especially in geum river and yeongsang/seomjin river.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.2
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• pp.285-294
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• 2012

Current urban stream conditions and their restoration projects were investigated by surveying the urban stream management experts in 29 cities with high population density (more than 1,000person/$km^{2}$). The survey results showed that the ratio of covered urban streams decreased by 1.4% (from 14% to 12.6%) in the last 5 years through steady river restoration projects promoted by governments. Nonetheless, 36.3% of 369 urban streams surveyed still report stream depletion problems; therefore, more efforts to alleviate the problems caused by distorted water circulation of urban streams are still necessary. Water depletion in many local urban streams, unlike national rivers, is accelerated due to negligence in stream management, budget shortage, and other reasons. To prevent stream depletion, the use of reclaimed water is suggested as one of the prevention plans. When available amounts of reused sewage are estimated through actual available nationwide sewage discharges of each watershed and instream flow of stream, annual instream flow supply of 780 million $m^{3}$ is expected; 4.8% reduction in the pollution load of public sewer treatment facilities is expected; and the creation of new value through water reuse service is expected. Thus, it is important for the reviews of feasibility and alternatives of water reuse projects for flow augmentation to consider not only investment budget reductions, but also environmental aspects. Also it is necessary to provide the financial support of unified government with strict water quality management policy.