• Journal of Environmental Impact Assessment
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• v.12 no.5
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• pp.359-367
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• 2003

The total pollution load management system of watershed has been implemented upon Special Law pertaining to the Han River Watershed Water Quality Improvement and Residents Support, Special Law pertaining to the Nakdong River Watershed Water Management and Residents Support, Special Law pertaining to the Youngsan River Watershed Water Management and Residents Support, and Special Law pertaining to the Seomjin River Watershed Water Management and Residents Support in Korea since 2002. But many other similar systems with total pollution load management system of watershed are being operated separately or independently, even though its purpose is nearly same with those of the total maximum pollutants load management in Law on Water Quality Environmental Protection, environmental impact assessment(EIA) in Law of Impact Assessment on Environment, Transportation and Disaster and Pre-environmental assessment of Environmental Policy Act. Therefore the contents of total pollution load management system of watershed and many other related systems could be overlapped and at some times have inconsistency among them. This study suggests first the integrated operation of total pollution load management system of watershed, EIA, pre-environmental assessment, urban planning, and sewage planning and secondly EIA system development by integration of EIA and pre-environmental assessment and strategic environmental assessment(SEA).

• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.180-184
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• 2016

In this study, we evaluated complex media with influent sewage water (ISW) to isolate novel taxa of bacteria. It was possible to cultivate 13 genera using the complex media with ISW. Additionally, more diverse genera were identified at 37℃ than at 25℃, using the complex media with ISW. Total 12 strains of 179 bacterial isolates were shared less than 97% 16S rRNA gene sequence similarities with any known species. These isolates could be assigned to genera Tessaracoccus, Paracoccus, or Candidimonas (or Paralcaligenes).

• Journal of Environmental Health Sciences
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• v.42 no.4
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• pp.274-279
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• 2016

Objectives: We investigated bacterial diversity in the Han River water resource protection area in order to provide basic microbiological information on the drinking water safety of the Seoul metropolitan region. Methods: Samples were collected in the spring and winter, but not during the rainy season. Pyrosequencing, gene amplification, and extraction of nucleic acids were employed in this study. Results: In total, 57 and 48 operational taxonomic units were respectively analyzed in samples collected during spring and winter. Proteobacteria were predominant in all samples. The samples contained phylogenetically diverse bacterial communities, with eleven major phyla and 36 genera. Cyanobacteria were predominant in the spring samples, but not in the winter samples. The predominant species in the samples collected during both seasons belonged to the genus Aquamicrobium and Bradyrhizobium. Moreover, no pathogenic bacteria were detected in the samples. Conclusion: Proteobacteria were predominant in the samples from the Han River water source protection area. Cyanobacteria were more predominant in the spring samples than in the winter samples, but Aquamicrobium and Bradyrhizobium were predominant in both sampling seasons.

• Journal of Korean Society on Water Environment
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• v.30 no.6
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• pp.632-637
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• 2014

Proficiency testing by interlaboratory comparisons is used to determine the performance of individual laboratories. In order to verify the quality of acute toxicity testing with Daphnia magna, National Institute of Environmental Research in South Korea is regularly organizing interlaboratory comparisons to estimate the analytical accuracy of different laboratories. Total 58 laboratories located in South Korea took part in interlaboratory proficiency testing scheme with three proficiency testing samples. TU(Toxic Unit) values of each laboratory were determined and robust z-score was calculated in order to evaluate the proficiency levels. Based on the robust z-score classification, 74% of the participant laboratories showed a satisfactory performance (43 laboratories). The main reason of 'unsatisfactory' performance seemed to be considered that the unsuitable management of test organism incubation system and the lack of experience on the identification of the test organism condition by effect of toxicity.

• Journal of Environmental Impact Assessment
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• v.9 no.1
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• pp.13-24
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• 2000

This paper presents a study of water quality model applications in environmental impact statements which were submitted during recent years in Korea. Most of the applications have reported that the development projects would have significant impacts on the water quality, especially, of streams and rivers. The water quality models, however, were hardly used as an impact prediction tool. Even in the cases where models were used, calibration and verification studies were not performed and thus the predicted results would not be reliable. These poor model applications in environmental impact assessment can be attributable to the fact that there were no available model application guidelines as well as no requirements by the review agency. In addition, the expected waste loads were improperly estimated in most cases, especially in non-point sources, and the predicted parameters were not good enough to understand water quality problems expected from the proposed plans. The effects of mitigation measures were not analyzed in most cases. Again, these can be attributed to no formal guidelines available for impact predictions until now. A brief guideline is described in this paper, including model selection, calibration and verification, impact prediction, and analysis of effects of mitigation measures. The results of this study indicate that the model application should be required to overcome the current improper predictions of environmental impacts and the guidelines should be developed in detail and provided.

• Journal of Korean Society on Water Environment
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• v.29 no.4
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• pp.514-522
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• 2013

The major 24 tributaries in Nam-River mid-watershed were monitored for discharge and water quality in order to understand the characteristics of the watershed and to select the tributary catchment for improving water quality. According to the analytical results of discharge and water quality monitoring data of 24 tributaries, the mean value of discharge below $0.1m^3/s$ was 62.5% among the monitored tributaries and it mostly exceeded the water quality standards of Nam-river mid-watershed ($BOD_5$ = 3 mg/L, T-P = 0.1 mg/L over). According to the stream grouping method and the water quality delivery load density ($kg/day/km^2$) based on the results of tributary discharge and water quality monitoring, the tributary watersheds for improving the water quality were selected. In the Nam-River mid-watershed, tributaries in the GaJwaCheon, HaChonCheon catchment (Group D, $BOD_5$ = 3 mg/L over) and in the UirYeongCheon, SeokGyoCheon catchment (Group A, T-P = 0.1 mg/L over), which have a small flow (and/or large flow) and a high concentrations of water pollutants. The various water quality improving scheme for tributaries, in accordance with the reduction of potential point source pollution by living sewage and livestock wastewater, should be established and implemented.

• Journal of Korean Society on Water Environment
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• v.36 no.6
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• pp.621-635
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• 2020

Water quality models are scientific tools that simulate and interpret the relationship between physical, chemical and biological reactions to external pollutant loads in water systems. They are actively used as a key technology in environmental water management. With recent advances in computational power, water quality modeling technology has evolved into a coupled three-dimensional modeling of hydrodynamics, water quality, and ecological inputs. However, there is uncertainty in the simulated results due to the increasing model complexity, knowledge gaps in simulating complex aquatic ecosystem, and the distrust of stakeholders due to nontransparent modeling processes. These issues have become difficult obstacles for the practical use of water quality models in the water management decision process. The objectives of this paper were to review the theoretical background, needs, and development status of water quality modeling technology. Additionally, we present the potential future directions of water quality modeling technology as a scientific tool for national environmental water management. The main development directions can be summarized as follows: quantification of parameter sensitivities and model uncertainty, acquisition and use of high frequency and high resolution data based on IoT sensor technology, conjunctive use of mechanistic models and data-driven models, and securing transparency in the water quality modeling process. These advances in the field of water quality modeling warrant joint research with modeling experts, statisticians, and ecologists, combined with active communication between policy makers and stakeholders.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.615-623
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• 2012

In this study, we evaluate the corrosion indexes (CI) such as Langelier Index (LI), Larson ratio (LR), Ryznar saturation index (RSI), Aggressiveness index (AI) of water quality for raw water, treated water and water in distribution reservoir at major eight drinking water treatment plants (DWTPs) in Korea. By analyzing secondary contamination of tap water, the variation of secondary contaminants was investigated with regard to pipe materials, aging and corrosion index (CI). In addition, we suggested an appropriate CI applicable water quality and the management plan for CI monitoriing. All CI showed corrosive water quality, and they did not change significantly in the distribution network. However, Copper (Cu), iron (Fe) and zinc (Zn) concentrations as secondary contaminants increased through the distribution network. Among CI, LI was most sensitive to changes in raw water quality and drinking water treatment. Also, it has high correlations with other indexes such as RSI, AI. Therefore, LI is considered as an appropriate CI to the domestic water quality. Based on these result, we propose LI as a drinking water quality standard to control the pipe corrosion from DWTPs.

• Journal of Environmental Impact Assessment
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• v.17 no.6
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• pp.373-380
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• 2008

The Ministry of Environment plans to improve quality of water which is achieved over 85% in rivers and 94% in lakes of the whole country as "Good Water" until 2015. Also, the law of evaluation of water quality and water quality goal were made newly. So, the water quality has evaluated by using new law since 2007. This study evaluated whether "Good Water" and" Water Quality Goal" were achieved or not in 22 middle-sized districts and major 10 lakes of Geum river. The achievement rates of rivers decreased and the achievement rates of lakes mostly were the same for 5 years. In 2007, the achievement rates of "Good Water" were 50% in rivers and 50% in lakes. The achievement rate of "Water Quality Goal" were 59.1% in rivers and 20% in lakes. The water quality in 2007 was evaluated worse than last year in case of rivers. The evaluations of Korea-Comprehensive Water Quality Index(K-CWQI) showed that achievement rates of "Water Quality Goal" were 81.8% in rivers and 0% in lakes. The statistical correlation analysis showed that correlations between BOD and COD were meaningful at the downstream, compared to upstream, generally. In case of lakes, correlations between COD and temperature were meaningful. Also, correlations between COD and Chl-a were meaningful. The Trophic State Index ($TSI_{KO}$) showed that the half of lakes are major over eutrophic status in lakes. These analytical methods such as K-CWQI, $TSI_{KO}$, statistical correlation analysis could be additionally helpful for evaluation of water quality and provide basis data for understanding characteristics of watershed in Geum river.

• Journal of Korean Society on Water Environment
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• v.33 no.5
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• pp.525-530
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• 2017

The attainment ratios of the water quality goals of the 114 mid-watershed representative stations, examined during the period2011 to 2015, were evaluated in the study. Of the four major river basins, the attainment ratio on water quality goal of the Geum River basin turned out to be the lowest. As a result of formal evaluation of the attainment ratios of BOD, COD and TOC, it was found that the attainment ratio of COD was much lower than that of BOD and TOC (I a circumstance thought to be caused by the higher COD/BOD and COD/TOC ratios of the water quality of the river than those of the environmental water quality standard). As well, higher COD/BOD and COD/TOC of wastewater discharged from point and non-point sources (other than those of the environmental water quality standards) might possibly represent one of the reasons. We also compared attainment ratio between the main stream and tributaries, which indicated that the higher attainment ratio was present in the main stream. The attainment ratio is also documented as more significant in the winter season than the summer season, possibly due to the contribution of non-point pollutants swept in by rain during the summer season during documented periods of high precipitation. Thus, water quality management in summer season and improvement of water quality of the tributaries might be important as a means of increasing attainment ratio on water quality goal.