• Journal of Korean Society of Water and Wastewater
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• v.19 no.6
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• pp.728-737
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• 2005

Water quality of the Hwanggujicheon is poor because of the rapid housing and development in the large area of the basin. Establishment of water quality management strategy, based on the pollution sources survey and pollutant loads estimation, has to be established for the preservation of the stream water quality of the region. In this study, waste load allocation model to achieve the water quality goal of the stream and the optimization of pollutant load reduction, was developed. Nonpoint pollutant loads calculated by runoff model in the previous study are utilized for pollutant loads estimation of the drainage areas in this study. From the application result of the allocation model, water quality goals of the Hwanggujicheon that can be achieved as a matter of fact are BOD 8 mg/L. To achieve these goals, 23% of effluent BOD loads have to be reduced in the basin.

• Journal of Ocean Engineering and Technology
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• v.22 no.5
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• pp.75-82
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• 2008

As a basic study for establishing a countermeasure for an oxygen deficient water mass (ODW), we investigated the variation of ODW volume according to the enforced total pollution load management in Jinhae Bay. This study estimated the inflowing pollutant loads into Jinhae Bay and predicted the reduction in ODW by using a sediment-water ecological model (SWEM). The result obtained in this study are summarized as follows: 1) The daily average pollutant loads of COD, SS, TN, TP, DIN, and DIP inflowing into Jinhae bay in 2005 were estimated to be about 12,218 kg-COD/day, 91,884 kg-SS/day, 5,292 kg-TN/day, 182 kg-TP/day, 4,236 kg-DIN/day, and 130 kg-DIP/day. 2) The calculated results of the tidal current by the hydrodynamic model showed good agreement with the observed currents. Also, an ecological model well reproduced the spatial distribution of the water quality in the bay. 3) This study defined the ODWDI (ODW decreasing index) in order to estimate the ODW decreasing volume caused by a reduction in the inflowing pollutant loads. As a result, the ODWDI was predicted to be about 0.91 (COD 30% reduction), 0.87 (COD 50% reduction), 0.79 (COD 70% reduction), 0.85 (ALL 30% reduction), 0.66 (ALL 50% reduction), and 0.45 (ALL 70% reduction). The ODW volume was decreased 1.5 $\sim$ 2.6 times with a reduction in the COD, TN, and TP inflowing pollutant loads compared to a reduction in just the COD inflowing pollutant load. Therefore, it is necessary to enforce total pollution load management, not only for COD, but also fm TN and TP.

• Journal of Korean Society on Water Environment
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• v.31 no.2
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• pp.166-180
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• 2015

Pollutant in watersheds comes from two major sources which are NPS (nonpoint source pollution) and PS (point source pollution). Most of the pollutant can be treated by wastewater treatment plants. However, wastewater treatment plants may not be an appropriate practice to improve water quality for the watersheds with large portion of NPS pollutant and NPS pollution from direct runoff and baseflow has different characteristics. Therefore the practices to improve water quality need to be comprehensive for pollutants by both direct runoff and baseflow. Riparian buffer, one of practices to manage pollutant in watershed, has been applied to reduce pollutant not only from direct runoff but also baseflow. In this study, the scenarios for pollutant reduction by wastewater treat plants and the nitrogen reduction by riparian buffer were simulated using SWAT-REMM to suggest an effective plan for pollutant reduction from baseflow. Riparian buffer provided nitrogen reduction of 0.2~75.0% in YbB watershed and 38.0~47.0% in GbA watershed. The result indicates that riparian buffer is effective to reduce the pollutant especially from baseflow, and it suggested as suitable for the a watershed which WWTP discharge is not capable to reduce enough pollutant.

• Journal of Korean Society on Water Environment
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• v.37 no.6
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• pp.469-482
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• 2021

The recent climate change and urbanization have seen an increase in runoff and pollutant loads, and consequently significant negative water pollution. The characteristics of the pollutant loads vary among the different flow regime depending on their source and transport mechanism, However, pollutant load reduction based on flow regime perspectives has not been investigated thoroughly. Therefore, it is necessary to analyze the effects of concentration on pollutant load characteristics and reductions from each flow regime to develop efficient pollution management. As non-point pollutants continuously increase due to the increase in impervious area, efficient management is necessary. Therefore, in this study, 1) the characteristics of pollutant sources were analyzed at the Dalcheon Basin, 2) reduction of nonpoint pollution, and 3) reduction efficiency for flow regimes were analyzed. By analyzing the characteristics of the Dalcheon Basin, a reduction efficiency scenario for each pollutant source was constructed. The efficiency analysis showed 0.06% to 5.62% for the living scenario, 0.09 to 24.62% for the livestock scenario, 0.17% to 12.81% for the industry scenario, 9.45% to 38.45% for the land scenario, and 9.8% to 39.2% for the composite scenario. Therefore, various pollution reduction scenarios, taking into account the characteristics of pollutants and flow regime characteristics, can contribute to the development of efficient measurements to improve water quality at various flow regime perspectives in the Dalcheon Basin.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.722-727
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• 2017

Livestock manure is known to be the main cause of non-point pollution in agricultural areas. The pollutant reduction ratio of livestock manure recycling to fertilizers was measured in order to analyze the effect on the water quality of the Total Maximum Daily Load (TMDL) system in Korea. The reduction ratio has been applied by theoretical consideration without a survey, and there is no value for Total Organic Carbon (TOC) newly introducing any organic items. The reduction ratio of each pollutant from this study was revealed as follows: TOC, BOD, T-N and T-P were 0.34, 0.60, 0.37, and 0.42 for individual farm and 0.38, 0.61, 0.45 and 0.44 for entrustment facilities, respectively. The reduction ratio of individual farm was surveyed as TOC 0.63, BOD 0.62, T-N 0.42 and T-P 0.32 for liquid fertilizer, and TOC 0.30, BOD 0.64, T-N 0.40 and T-P 0.48 for compost. The total reduction ratio was derived by multiplying the ratio for liquid fertilizer and compost by the respective load. Compared to the pollutant reduction ratio of the individual farm with entrustment facilities marking the higher in liquid fertilizer and the lower in compost. Through this study, we found the difference of pollutant reduction ratio between a livestock manure recycling process and facilities. Although phosphorus is known as a preservative matter, the treatment efficiency of T-P is analyzed to decrease by chemical precipitation.

• Journal of Korean Society on Water Environment
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• v.27 no.5
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• pp.689-698
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• 2011

In South Korea, Total Maximum Daily Load (TMDL) has been enforced since 2004 to restore and manage water quality in the watersheds. However, the appraisal of TMDL in South Korea has lots of weaknesses to establish the plan for recovery of water quality because it just evaluates the target water quality during the particular flow duration interval. In the United States, Load Duration Curve (LDC) method bas been widely used in the TMDL to evaluate the water quality and pollutant loads considering variation of stream flow. In a recent study, web-based Load Duration Curve system was developed to create the LDC automatically and provide the convenience of use. In this study, web-based Load Duration Curve system was applied in the Gapyeongcheon watershed using the daily flow and 8-day interval water quality data, and Q-L Rating Curve was used to evaluate the water quality and pollutant load in the watershed, also. As a result of study, water quality and pollutant load in Gapyeongcheon watershed were met with water quality standard and allocated load in the all flow durations. Web-based Load Duration Curve system could be applied to the appraisal of South Korean TMDL because it can be used to judge the impaired flow duration and build up the plan of load reduction, and it could enhance the publicity. But, web-based Load Duration Curve system should be enhanced through addition of load assessment tools such as Q-L rating curve to evaluate water quality and pollutant load objectively.

• Journal of Korean Society on Water Environment
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• v.29 no.1
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• pp.66-73
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• 2013

Total Maximum Daily Loads (TMDLs) system was introduced to manage pollution load of watershed and to improve water quality of unit watershed so that it is possible to protect dringking water soureces. Load allocation observation is the most important factor in TMDLs system. Because if load allocation is not observed, it is difficult to achieve water quality goal of unit watershed. Also it is impossible to improve water quality of the drinking water sources. Therefore it is necessary to apply some kind of sanctions (penalty) in case of excess of load allocation. The sanctions have to be, however, applied differently based on various reduction plan types, i.e., using the reduction load planed in 2nd phase, delay the completion, additional reduction in 2nd phase, error of the pollution sources, etc. Moreover, the penalty load should be properly imposed, lest it should be overburden the provence. The reduction load trade inter province must be restrictively permmitted only the same unit watershed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.3
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• pp.149-155
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• 2000

The effects of the WfP construction are analysed quantitatively based on the pollutant budget change in Masan Bay. The reduction effects of the watershed pollutant loads are clearly shown, while the positive influence of the water quality (WQ) are not substantial because the pollutant load also increased continusly after WTP construction. The reduction effects of the COD, 55, TN and TP parameters are 17.6%, 68.9%,66.7%, and 38%, respectively in Masan Bay (zone I). The environmental condition of the northern part of Chinhae Bay (zone ll), however, is slowly degraded because of the direct and indirect effects - effluents discharge from the WTP and pollutants release from the sediment, respectively.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.5
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• pp.17-27
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• 2018

The objective of this study is to identify the priority area where the nonpoint source pollution (NPS) management is required and to set up the load reduction goals for the identified priority area. In this study, the load duration curve (LDC) was first developed using the flow and water quality data observed at 286 monitoring stations. Based on the developed LDC, the priority area for the NPS pollution management was determined using a three-step method. The 24 watersheds were finally identified as the priority areas for the NPS pollution management. The water quality parameters of concern in the priority areas were the total phosphorus or chemical oxygen demand. The load reduction goals, which were calculated as the percent reduction from current loading levels needed to meet target water quality, ranged from 67.9% to 97.2% during high flows and from 40.3% to 69.5% during moist conditions, respectively. The results from this study will help to identify critical watersheds for NPS program planning purposes. In addition, the process used in this study can be effectively applied to identify the pollutant of concern as well as the load reduction target.

• Journal of Korean Society on Water Environment
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• v.36 no.2
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• pp.98-108
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• 2020

The purpose of this study was to evaluate water quality in Hapcheon dam via using the Hydrological Simulation Program-Fortran (HSPF) model and applied livestock reduction scenarios. Hapcheon dam watershed input data for the HSPF model were established using the stream, land use, digital elevation map and meteorological data and others. The HSPF model was calibrated and validated using the observed water quality data from 2000 to 2016. For water quality simulation, we calculated the generated and discharge loads of the population, livestock, industry and land use following the guideline provided by the Ministry of Environment. The pollutant data were obtained from National Institute of Environmental Research (NIER). The monthly discharge load were estimated by applying the delivery rate. The calibration and validation results showed that the annual mean BOD had a difference of 0.22 mg/L and an error of ±13 %, T-N had a difference of 0.66 mg/L and an error of ±16 % and T-P had a difference of 0.027 mg/L and an error of ±13 %. In order to evaluate the nonpoint pollutants management effects, we applied livestock reduction scenarios because livestock consists of the largest portion of pollutants. As a result of the 20 % of livestock reduction, BOD, T-N and T-P decreased by 3 %, 1 % and 3 %, respectively. When 40 % of livestock reduction was applied, BOD, T-N and T-P decreased by 5 %, 3 % and 4 %, respectively. Based on the results of this study, effective pollutant management methods can be applied to improve the water quality and achieve the target water quality of Hapcheon dam watershed.