• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.413-419
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• 2010

A silica mine monitoring was conducted from March to December in 2008 to measure rainfall, runoff amounts and pollution loads. A total of 13 rainfall-runoff events were measured and analyzed with respect to runoff ratio, pollutant concentration and load, and initial flush. Over rainfall-runoff events, 95% confidence range of SS concentration was 942.5~2,056.2 mg/L. Other measured water quality indices also showed relatively large variation. This wide concentration variation was thought to be caused by the bare working ground of the mine that was used to store, process and transport the mined silica. Total pollution load of the 13 rainfall-runoff events was SS 17,901 kg/ha, $COD_{Cr}$ 160.9 kg/ha, $COD_{Mn}$ 111.24 kg/ha, BOD 79.6 kg/ha, T-N 13.8 kg/ha, T-P 3.5 kg/ha, and TOC 39.3 kg/ha. Initial flush was not well observed except SS. Very high SS concentration and load was occurred when rainfall was large. Therefore, it was recommended to manage the bare ground not to discharge excessive pollutants during wet days by covering the ground or constructing runoff treatment systems such as a sediment basin.

• 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.

• Journal of Korean Society on Water Environment
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• v.31 no.5
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• pp.569-575
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• 2015

The current Total Pollution Load Control (TPLC) sets the Target Water Quality (TWQ) by utilizing the delivery ratio, unit loads, and water quality modeling, it also allocates the watershed's permitted discharge load. Currently, common target pollutants of every unit watershed in TPLC are BOD and T-P. This study has reviewed the 1th and 2th of TWQ setting process for the Nakdong River 3th TWQ setting in Total Pollution Load Control (TPLC). As a result of review, 1th and 2th were divided into one management basin (mulgeum) for setting management goals. However, 3th was divided into six management basins (mulgeum, gnagjeong, geumho river, nam river, miryang river, end of nakdong river). The principle of management goal setting were to achieve the objective criteria of Medium Areas for the linkage of the water environment management policy. And Anti-Degredation (principle of preventing deterioration) were applied to the 3th TWQ. Also, additional indicators were considered in accordance with the reduction scenarios for the final management goals.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.11
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• pp.785-794
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• 2013

Combined sewer overflows during rainfall events contain sewer sediments and surface pollutants. This can cause significant chemical, physical and biological problems to receiving watershed. However, there are no method that can commonly apply to decide criteria for controlling the pollutant load. In this study, it sets up the reduction goals of combined sewer overflow through long-term simulation using the rainfall-runoff model. From a review of domestic and foreign management standard of combined sewer overflow for this, it makes decision that 60% (phase 1), 85% (phase 2) of total pollutant load and frequency per year for reduction goals is more proper. Also, the result of analyzing long-term simulation (minimum 10 years) applied to research basin indicates that reduction goals of BOD pollutant load are 1,123 kg (phase 1) and 2,374 kg (phase 2), and overflow volumes for research objective achievement are $11,685m^3$ (phase 1) and $24,701m^3$ (phase 2).

• Journal of Korean Society on Water Environment
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• v.24 no.3
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• pp.333-339
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• 2008

This study was carried out to assay the relationships between empirical factors and water quality in 23 agricultural reservoirs. Based on the trophic state index (TSI) deviation analysis, phosphorus in type II and III was the primary limiting factor on algal growth. BOD, COD, TP and chl.a concentration in type III reservoirs showed higher concentration than those of other types, while SS and TN concentration was no noticeable difference among three types. Characteristics of type III reservoirs showed large reservoir surface and drainage area, large surface area to volume (SAV) ratio, small drainage area to reservoir area (DA/RA) ratio, relatively old age, large paddy field and upland field to drainage area ratio (Mean 17.4%) and high generation and discharge loads compared to other types of reservoirs. In type I and II reservoirs, trends of BOD, TN, TP concentration in water column, were similar to those of the discharge load of pollutants. Although type II reservoirs generally showed low phosphorus discharge loads compared to type I reservoirs, TP and chl.a concentration in water column was greater than that of type I. Characteristics of type II reservoirs showed relatively large SAV ratio and old age compared to type I reservoirs and was similar to those of type III including eutrophic reservoirs.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.136-144
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• 2018

The Ministry of the Environment conducts a water environment management plan and TMDL(Total Maximum Daily Load) for integrated watershed management, and determines whether the target water quality is achieved using water quality monitoring data. The concentration of monitoring points located in the downstream of the watershed is the outcome of complicated mechanisms such as influx of pollutants from the tributaries of the watershed and self-purification of river water. The purpose of this study is to analyze the effect of main stream and tributary water quality on the target water quality point using the water pollution source tracking and exceedance rate of watershed. In this study, FDC and exceedance rate analysis were performed on six water quality items including BOD and T-P, which are the targets of TMDL. Water quality items and points affecting the target water quality point were derived from flow rate. In this study, the pollution source tracking through FDC analysis and exceedance rate analysis will be able to establish more efficiently the water quality management strategy for each branch to achieve the target water quality.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.355-362
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• 2000

The objective of this paper is to estimate the pollutant load based on event mear concentrations(EMC) in industrial complex. Eight sub-basins in the Chongju industrial complex were selected for sampling and study with different characteristics during the period from June 1997 to August 1998. During the storm events, measured EMC ranges of $BOD_5$, COD, SS, TKN, TP, HEM, $NO_3-N$, $PO_4-P$, Cr, Pb, Cu and Fe in the industrial complex watersheds were 11~176mg/L, 40~502mg/L, 23~633mg/L, 104~20.9mg/L, 0.22~7.51mg/L, 12.7~548.7mg/L, 0.06~2.66mg/L, 0.12~3.39mg/L, 0.01~0.50mg/L. 0.02~0.42mg/L, 0.01~0.15mg/L and 1.29~11.51mg/L respectively. And the calculated annual average pollutant unit loadings of $BOD_5$ COD, SS, TKN, $NO_3-N$, $PO_4-P$, TP, HEM, Cr, Pb, Cu and Fe were 374.4kg/ha/yr 924.1kg/ha/yr, 983.6kg/ha/yr, 48.8kg/ha/yr, 8.1kg/ha/yr, 9.7kg/ha/yr, 17.8kg/ha/yr 943.0kg/ha/yr, 0.7kg/ha/yr, 0.9kg/ha/yr, 0.3kg/ha/yr and 28.9kg/ha/yr, respectively.

• 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 Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.121-129
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• 2008

Major factors affecting water quality in rivers are transportation, input of pollutant loads and kinetic transformation of pollutants. Government level decision makings on water quality management are based on steady state water quality modeling. However, it is more than often that such a steady state assumption is far from real situations in rivers. Therefore, it is unavoidable to have modeling errors in water quality modeling especially for steady state modeling for longer period of time. Authors attempted to identify sources of errors in results of steady state models and thus tried to find out ways to minimize those errors. Three water quality models, QUAL2E (Brown et al., 1983), QUAL2K (Chapra et al., 2006) and CAP (Seo and Lee, 2000) were applied to the lower stream of the Geum River. $BOD_5$ and COD tend to underestimate observed data while TN and TP showed relatively smaller errors. QUAL2E model provided best calibration results for BOD5 and TP and QUAL2K model showed best calibration results for TN. Since these errors are only relative values, it was difficult to conclude which model is better performing in certain situations. The most probable reasons for errors in water quality modeling are; 1) inappropriate consideration on flow characteristics, 2) lack of information on incoming pollutant load and 3) inappropriate location of sampling for water quality analysis.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.654-663
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• 2010

Attention has increasingly focused on the pollutant load discharged from rural area since the enforcement of total maximum daily loads (TMDLs) in korea. As one of the methods to control the inflow of pollutant load during wet weather events, local governments are attempting to apply non-point source control facility. To design those facilities appropriately, it is essential to understand the runoff characteristics of pollutants such as TSS, $BOD_5$, $COD_{Cr}$, TP and TN. In the paper, the quantitative analyses for pollutant runoff characteristics were examined in a small rural watershed with the area of about 53 hectares. For a dry weather day and wet weather events, variation patterns of dry weather flow and runoff characteristics of wet weather flows were monitored and investigated. The runoff model using XP-SWMM reflecting the landuse types of the watershed in detail was simulated to perform the sensitivity analyses for several factors influencing on their hydrograph and pollutographs. As a result, for the case of medium and small rainfall events (i. e. total rainfall of 35.8 and 17.5 mm), the impervious area including green house, roof and road which covers relatively low portion of total area (i. e. 16%) caused substantial first flush and the majority of total runoff load. Therefore, it has been concluded that the runoff characteristics of each pollutant and distribution of impervious area should be considered for the establishment of the control strategy of non-point pollutant runoff at a rural area.