• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.324-331
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• 2007

This study was conducted to evaluate the influence of pollutant loads on the water quality in the Goseong reservoir from May 2005 to October 2006. Annual total runoff at the Goseong-cheon watershed was 968.0 mm in 2005, 382.6 mm in 2006, respectively. The mean concentration of BOD, COD and SS in the stream were 2.28, 6.03, 46.97 mg/L in rainy seasons and 0.95, 2.14, 6.05 mg/L in dry seasons at SWT C sub-watershed. Total-N concentrations ranged from 2.60 to 3.18 mg/L at SWT C sub-watershed, which was generally higher than the quality standard of agricultural water (1.0 mg/L). Total-P concentrations ranged from 0.044 to 0.130 mg/L at SWT C sub-watershed. Measured pollutant loads in the SWT C sub-watershed were 36.7 kg/day of BOD, 72.3 kg/day of T-N and 2.3 kg/day of T-P in 2005 at SWT C sub-watershed, 63.9 kg/day of BOD, 82.8 kg/day of T-N and 1.1 kg/day of T-P in 2006 at SWT C sub-watershed, respectively. In the analysis of the effluent characteristics for NPS pollutants, it appeared that the loading rates of effluent from SWT C watershed were, respectively, BOD 62.3%, T-N 69.6%, T-P 71.1%, SS 70.1% during the rainy season in 2006. The calculated T-N daily pollutant loadings by the unit loading factor method from each sub-watershed were much greater than observed, but the calculated T-P daily pollutant loadings much lesser than observed.

• Journal of Environmental Science International
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• v.26 no.4
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• pp.433-445
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• 2017

In recent years, the United States has used the Load Duration Curve (LDC) method to identify water pollution problems, considering the size of the pollutant load in the entire stream flow condition to effectively evaluate Total Maximum Daily Loads (TMDLs). A study on the improvement of the target water quality evaluation method was carried out by comparing evaluations of two consecutive years of water quality and LDC data for 41 unit watersheds (14 main streams and 27 tributaries). As a result, the achievement rate of the target water quality evaluation method, according to current regulations, was 68-93%, and that by the LDC method was 82-93%. Evaluating the target water quality using the LDC method results in a reduction in the administrative burden and the total amount of planning as compared to the current method.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.413-422
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• 2014

In national water quality policy, it changed previous regulation method that focuses on concentration of pollutants in effluent water to the way that regulates total amount of pollutants. The target of water quality in watershed of each river was set up, as the government instituted Total Maximum Daily Loads(TMDL). In order to accomplish successfully TMDL, it requires that the amount of pollutant loads discharged from point and nonpoint pollutant source should be investigated. This study, therefore, conducted the monitoring of the stormwater runoff at field region in farming area. And pollutants loads and unit loads discharged from field region results is calculated. As a result, the concentration of pollutants were calculated as follows: 10.5 BOD mg/L, 19.6 $COD_{Mn}$ mg/L, 4.5 TN mg/L and 2.4 TP mg/L. The unit load of BOD, $COD_{Mn}$, TOC, TSS, TN and TP discharged from field region, also, were determined to $31.8kg/km^2/yr$, $56.7kg/km^2/yr$, $8.5kg/km^2/yr$, $560.9kg/km^2/yr$, $8.3kg/km^2/yr$ and $5.1kg/km^2/yr$, respectively. It was identified that there were some differences of unit loads between the results obtained from this study and previous one. To calculate exact unit loads, therefore, long term monitoring should be conducted.

• Journal of Environmental Impact Assessment
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• v.14 no.2
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• pp.63-73
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• 2005

This study was performed to characterize stormwater runoff of pollution material from nonpoint sources during rainfall in drainage basins of Hongjechun watershed, and to suggest management methods to control the first flush of nonpoint sources. We conducted 4 times of field surveys including 3 times of wet period and 1 times of dry period for 5 stations, which consist of 3 stations in main stream of Hongjechun and 1 station in tributaries of Sinyoungchun and Gukichun, respectively. The variation of pollutant concentrations in terms of BOD, COD, SS and TP was large depending on the flow rate of stormwater, while a little change of TN concentration was investigated. Depending on the rainfall event, the difference of flowrates, and runoff loadings was large, while the difference of those for dry wether period was not noticeable for various sub-basins. In the results of unit load calculation, the range of 153-277 kg/ha/yr for BOD, 222-422 kg/ha/yr for COD, 264-432 kg/ha/yr for SS, 40-70kg/ha/yr for TN, and 13-25 kg/ha/yr for TP was obtained for Hongjechun, Sinyoungchun, and Gukichun sub-basins. Compared with the previous studies, the result of this study was founded to be acceptable.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.4
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• pp.381-392
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• 2011

Pollutant loads calculated with unit factor method can not identity seasonal variations of pollutant inputs. Estimation of pollutant loads considering rainfall runoff can overcome these limits. SCS curve number method was applied to estimate runoff of each event of Koeup watershed of Koheung estuary lake. SCS curve numbers were calculated based upon land use, soil types of the catchment using GIS. Point and nonpoint source pollutant loads were summed up for total loads estimation. Those from nonpoint source were estimated by multiplying the calculated runoff and expected mean concentrations (EMC) presented by the Minister of Environment of Korea. DEM can present three dimensional views of a terrain, identity stream networks and flow accumulation. Furthermore, it can examine accumulated pollutant loads of specific point of a catchment. Therefore, cell based pollutant load estimation was attempted using DEM. ArcView was utilized to collect, store and manipulate spatial and attribute data of pollutant sources and features of the catchment. Cell-based DEM which was established by the GRID module of ARC/INFO was employed to estimate flows and pollutant loads.

• Journal of Wetlands Research
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• v.11 no.1
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• pp.75-82
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• 2009

The regulation of emission concentration for stream water qualities doesn't control quantitative increase on pollution loads, it has limits for improvement of water qualities. Total water pollution load management system(TMDL) can control the total amount of pollutant in waste water which is allowed to assign and control the total discharged pollutant loads in a permissible level. When it comes to generated wastewater value of TMDL system, there is difference between calculated value based on individual pollutant unit load and observed value. Calculated sewer inflow, calculated sewer outflow, measured sewer inflow, and measured sewer outflow at dry season are $26,460.9m^3$/d, $17,778.6m^3$/d, $17,106.1m^3$/d and $19,033.9m^3$/d respectively, Calculated sewer inflow, calculated sewer outflow, measured sewer inflow, and measured sewer outflow at rainy season are $49,512.2m^3$/d, $18,628.7m^3$/d, $30,918.2m^3$/d, $19,700.7m^3$/d respectively. This result presents the necessity to acquire the precise observed data to fulfill the efficient TMDL system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5B
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• pp.273-285
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• 2012

Current TMDL based on the 'Polluter Pays Principle' in Republic of Korea is individually operated by each local government for the designed allocated pollution load of unit watershed and unit district. However, unlike the motion of the air contaminants, the polluted contaminants in a river move from upstream to downstream, and a river can affect to districts more than two. In addition, a decision making on the construction of a sewage treatment facilities follows the concept of 'economy of scale'. These reasons support the collaboration among local governments in order to reduce the costs in improving water quality. This study suggested a method to reduce water quality management cost by redistributing reduction load considering cost-effectiveness for an entire watershed. The assessment on the suggested method is conducted in Youngsan river watershed. Without variation in total load, reduction load assigned for unit watershed and unit district is retributed in the region where pollutant source is concentrated, and then water quality and cost reduction improved from the redistribution of reduction load is analyzed. The results show that the cost saved by the suggested method is KRW 124 billion for scenario-1 and 172 billion for scenario-2 considering total cost of KRW 788 billion for the existing plan. We expect that the suggested method is a good example to reduce water quality management cost in local governments for TMDL.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.4
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• pp.429-438
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• 2013

This study was to develop effective water quality management measures using LDC (Load Duration Curve) curves for TMDL (Total Maximum Daily Loads) unit watershed. Using LDC curves, major factors for BOD and T-P concentration loads generation (i.e. point source or non-point source) in the case study area (Geumho river basin) were found for different hydrologic conditions. Different measures to deal with the pollutant loads were suggested to establish BMPs (Best Management Practices). It was found that the target area has urgent T-P management methods especially at moist and midrange hydrologic conditions because of point source pollutants occurred in developed areas. One example measure for this could be establishment of advanced treatment facility. This study proved that the use of LDC was a useful way to achieve TWQ (Target Water Quality) on the target watershed considered. It was also expected that the methodology applied in this study could have a wider application on the establishment of watershed water management measures.

• The Journal of Engineering Geology
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• v.20 no.4
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• pp.401-407
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• 2010

This study was carried out to produce the characteristics of pollutant loads caused by a cherry tree plot as a nonpoint sources(NPS) unit in agricultural areas. The relationship between rainfall and runoff didn't show a good coefficient with 0.5. Despite precipitation amount was less than 20 mm, runoff occurred with $0.5\;m^3$ because of high rainfall intensity of 8.8 mm/hr. In contrast, runoff was not occurred when precipitation amount was 47.4 mm in one case. In that case the primal effect on runoff was not precipitation amount. Correlation between load of pollutants such as BOD, COD, TN and TP and runoff' volumes showed significantly positive values which were more than r = 0.92 for all pollutants except SS(r = 0.71). SS could be a proper factor for estimating pollutant loads of BOD, COD, TN and TP because of a high correlation more than r = 0.73 between SS load and pollutant loads of BOD, COD, TN and TP. Both Organics and nutrient pollutants could be reduced if we control SS in runoff. The highest concentration of TN was detected in the event which was affected by fertilization activities directly. Therefore fertilization must be considered as a function of impact parameters on TN load in agricultural areas.

• Journal of environmental and Sanitary engineering
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• v.22 no.4
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• pp.87-104
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• 2007

The objective of this study is to estimate the load of pollutants caused from the forest area among non-point pollutants within the Juam lake. The surveyed forest area was classified into broad-leaved, conifer, mixed and herbage area by forest tree type. Water quality and flux were investigated under rainfall and non-rainfall, respectively. Then, pollutant loading was evaluated by using the values of unit pollutant loading factor of each point and area of forest zone. Water quality analysis results of runoff by forest tree types were as follows. - Annual BOD, $COD_{Mn}\;and\;COD_{Cr}$ concentration of runoff in conifer area was high, and particle and biological recalcitrant compounds were flowed highly. - SS, T-N and T-P concentration was high in runoff from broad-leaved area, and biological degradable compounds was flowed. - Water quality of water from valley was maintained good under non-rainfall and could be utilized as fresh drinking water. Through water quality standard investigation, a countermeasure establishment was necessary to secure a good quality of drinking water - BOD, $COD_{Mn},\;and\;COD_{Cr}$ concentration of Bo-sung river was higher 1.5 times than other 2 streams, and because of high T-N, and T-P concentration in Songgwang stream, the management for this was necessary.