• Environmental Engineering Research
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• 제13권2호
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• pp.73-78
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• 2008

For a given soil-contaminated site, a level of soil contamination is characterized and decisions on risk may be made from the risk assessment. The study evaluated critical design factors for the determination of sample size in the sampling design plan and the assessment of soil contaminant- leaching to groundwater. Two variables, the minimum relative detectable difference (T) and coefficient of variation (CV) were evaluated for the sample size determination. The minimum number of samples can be appropriately determined by CV under a T value greater than or equal to 0.2. Soil-contaminant leaching to groundwater was evaluated by using the Soil Screening Level equation of U.S. Environmental Protection Agency and the Risk Based Screening Level equation of American Society for Testing and Materials, with the same input parameters. The groundwater concentrations estimated from soil contaminant concentrations were significantly affected by the Darcy velocity of groundwater and the organic content of soil.

• 지질공학
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• 제23권3호
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• pp.293-304
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• 2013

국내 현행 지하수법에서는 오염방지 시설에 관한 개략적인 설치규정만이 설정되어 있어서 대수층의 특성을 고려하지 않은 일률적인 오염방지 시설 기준이므로 지질에 따라 다양하게 발달하는 우리나라의 지하수자원을 효과적으로 보호해 주지 못한다. 최근에는 지하수오염방지에 중요한 기술과 장치로서 패커개발이 점차 주목을 받고 있다. 본 연구에서는 경북 안동시 서후면, 충남 연기군의 오염된 지하수공에 대하여 하부지하수오염방지시설로서 팩커의 적합성을 검토한 결과, 그 효과는 우수한 것으로 나타났다. 연구대상지인 경북 안동시 서후면 창풍리의 경우 팩커를 시공한 결과 탁도는 94%, 연기군 남면 눌왕리의 경우 질산성 질소는 60% 감소효과를 나타내었으며, 이로 인해 모든 수질검사항목에서 적합수질을 보였다. 지하수오염방지를 위해서는 정확한 관정카메라 촬영과 오염원 모니터링 분석을 실시하고, 이에 근거하여 지질특성, 풍화대심도, 파쇄대 발달, 대수층의 수리경사, 오염물의 이동경로를 파악한 후, 통합적으로 지하수오염 가능성을 평가하고, 이를 통하여 적절한 그라우팅과 케이싱 작업이 이루어져야 한다. 유용한 대수층 구간을 확보하여 오염물을 차단하는 그라우팅, 팩커장치, 케이싱은 지하수의 활용과 오염방지에 중요한 역할을 할 것으로 기대된다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 International Symposium
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• pp.58-69
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• 2003

Soil contamination in the United States is managed using a risk-based decision making process. In other words, we don't ask, 'how much soil contamination can be cleaned up\ulcorner' Instead we ask, 'how much contamination can be safely left in place\ulcorner' The determination of 'safe' levels of contamination is based upon the potential for exposure and the toxicity of the contaminants of concern in soil. Potential for exposure is determined by evaluating potential exposure pathways from source to receptor given current or reasonably anticipated land use. Soil cleanup goals are then calculated for any complete exposure pathways based upon toxicity and the route of exposure. In some cases, institutional or engineering controls are also used to limit the potential for exposure. In order to prevent a continuous degradation of environmental quality, risk-based cleanup approaches must be combined with strong contamination prevention programs. In addition, alternative risk management approaches should be incorporated into an overall risk reduction strategy.erall risk reduction strategy.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.25-39
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• 2003

Risk and exposure assessment for subsurface environment is very important for both aspects of health and environmental protection as well as making decision of remedial goal for engineering activities. Exposure due to hazardous chemicals in the subsurface environment is essential to assess risk lev121 to individual person, especially from soil and groundwater environmental media. In this paper, the status of soil and groundwater contamination is presented to discuss on the problem for environmental risk assessment. The methodologies of fate and exposure models are also discussed by conducting the case studies of exposure assessment for heavy metals, organic compounds, and dioxin compounds. In addition, the structure of exposure models and available data for model calculation are examined to make clear more realistic exposure scenarios and the application to the practical environmental issues. Three kinds of advanced remediation techniques for soil and groundwater contamination are described in this paper, The most practical method for VOCs is the bio-remediation technique in which biological process due to consortium of microorganisms can be applied. For more effective remediation of soil contaminated by heavy metals we have adopted the soil flushing technique and clean-up system using electro-kinetic method. We have also developed the advanced techniques of geo-melting method for soil contaminated by DXNs and PCB compounds. These techniques are planed to introduce and to apply for a lot of contaminated sites in Japan.

• Korean Journal of Hydrosciences
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• 제10권
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• pp.47-58
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• 1999

Protection of groundwater resources from contamination has been of increasing concern throughout the past decades. In practice, however, groundwater monitoring is performed based on the experience and intuition of experts or on the convenience. In dealing with groundwater contamination, we need to know what contaminants have the potential to threat the water quality and the distribution and concentration of the plumes. Monitoring of the subsurface environment through remote geophysical techniques or direct sampling from wells can provide such information. Once known, the plume can be properly menaged. Evaluation of existing methodologies for groundwater monitoring network design revealed that one should select an appropriate design method based on the purpose of the network and the avaliability of field information. Integer programming approach, one of the general purpose network design tools, and a cost-to-go function evaluation approach for special purpose network design were tested for field applicability. For the same contaminated aquifer, two approaches resulted in different well locations. The amount of information, however, was about the same.

• 대한환경공학회지
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• 제34권7호
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• pp.504-515
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• 2012

지하수는 전 세계적으로 널리 이용되는 음용수원이다. 하지만, 병원성 미생물에 의한 지하수 오염은 매우 심각한 환경문제로써 음용수의 수질을 저하시키고 인류의 건강을 위협한다. 지하수를 오염시키는 병원성 미생물은 바이러스, 세균, 원생동물 등이 있는데, 이중 바이러스는 박테리아나 원생동물보다 크기가 훨씬 작기 때문에 토양을 통과하는 과정에서 잘 제거되지 않고, 지하수 환경에서 이동성이 뛰어나다. 토양과 대수층에서 바이러스 거동 연구는 지하수의 병원성 미생물 오염 취약성을 판단하고 안전한 음용수원을 확보하는데 꼭 필요하다. 또한, 이러한 연구는 공중 보건을 위한 정책 및 규정을 제정하기 위한 중요한 정보를 제공한다. 본 논문에서는 최근까지의 지중 환경에서 바이러스 거동과 관련하여 수행된 연구들을 현장 조건에서 수행된 것과 실험실 조건에서 수행된 것으로 나눠 정리하였다. 또한, 이러한 연구들을 통해 알려진 바이러스의 거동에 영향을 미치는 인자들을 제시하였다. 그리고, 최근 바이러스 거동 연구에 널리 이용되는 박테리오파지의 특성을 정리하였고, 바이러스 거동을 모사하는데 이용되는 수학적 모델과 콜로이드 여과이론을 제시하였다. 지금까지의 연구결과를 바탕으로 향후 연구는 바이러스 오염원으로부터 지하수를 보호한다는 측면에서 바이러스 보호구역의 설정과 관련된 연구들이 활발히 진행되어야 할 것으로 판단된다. 특히, 바이러스 보호구역 설정과 관련하여 이격거리나 이동시간을 계산할 수 있는 수학적 모델을 개발하고 모델과 관련된 파라미터들의 정보를 축적하는데 집중되어야 할 것으로 판단된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권2_spc호
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• pp.1-15
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• 2020

Monitoring and assessing terminal electron accepting processes (TEAPs) are one of the most important steps to remediate contaminated sites via various in-situ techniques. TEAPs are a part of the microbial respiration reactions. Microorganisms gain energy from these reactions and reduces pollutants. Monitoring TEAPs enables us to predict degradability of contaminants and degradation rates. In many countries, TEAPs have been used for characterization of field sites and management of groundwater wells. For instance, US Environmental Protection Agency (EPA) provided strategies for groundwater quality and well management by applying TEAPs monitoring. Denmark has also constructed TEAPs map of local unit area to develop effective groundwater managing system, particularly to predict and assess nitrogen contamination. In case of Korea, although detailed soil survey and groundwater contamination assessment have been employed, site investigation guidelines using TEAPs have not been established yet. To better define TEAPs in subsurface environments, multiple indicators including ion concentrations, isotope compositions and contaminant degradation byproducts must be assessed. Furthermore, dissolved hydrogen concentrations are regarded as significant evidence of TEAPs occurring in subsurface environment. This review study introduces optimal sampling techniques of groundwater and dissolved hydrogen, and further discuss how to assess TEAPs in contaminated subsurface environments according to several contamination scenarios.

• Journal of Radiation Protection and Research
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• 제38권2호
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• pp.124-131
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• 2013

원전 운영자는 규제 지침에 따른 계획적 방출 감시 및 관리를 통해 환경 및 주민의 방사선 위해도를 합리적으로 가능한 한 낮게 유지하여 왔다. 그러나 최근 미국을 중심으로 한 일부 해외 원전에서 발생한 지하수 오염의 원인이 비계획적 방출로 드러남에 따라 이에 대한 관심이 커지면서, 비계획적 방출은 현재 미국 원전산업계의 최대 이슈로 대두되었다. 본 논문은 미국 원전의 비계획적 방출에 의한 지하수 오염 감시 사례 및 이에 대한 미국 원전 산업계 및 규제기관의 대응 상황의 소개를 통하여 향후 국내 원전 부지 지하수 감시의 효과적인 운영에 도움을 주는 것을 목표로 하였다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.291-295
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• 2002

We measured the concentrations of heavy metals and VOCs in groundwaters (N=38) in Seoul. The comparison of our data with U.S. Environmental Protection Agency's Maximum Contaminant Levels for Drinking Water and with the Korean Drinking Water Standards shows that most of the metals except for Fe and Mn do not exceed the levels. However, the concentrations of most heavy metals (esp., Zn, Cu, Cr, Ni) tend to increase in residential and industrialized areas. The examination of the metal speciation using Anodic Stripping Voltammetry (ASV) and TOC analyzer Indicates that large amounts of Zn occur as labile metal fraction, whereas Cu occurs as non- labile forms at many sites, possibly due to its tendency to be adsorbed onto inorganic colloidal particles to form electroinactive species in groundwater. The most frequently existed VOCs in Seoul groundwaters are trichloroethylene and tetrachloroethylene, especially in agricultural, industrial, and high traffic areas.

• Advances in environmental research
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• 제4권2호
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• pp.105-117
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• 2015

The groundwater is a very important part of the environment and must be protected for the benefit of the present and future generation. The contamination of soil and groundwater by chemicals has become an increasing concern in the recent past. These chemicals enter the groundwater system by a wide variety of mechanisms, including accidental spills, land disposal of domestic and industrial wastes and application of agricultural fertilizers. Once introduced into an aquifer, these contaminants will be transported by flowing groundwater and may degrade water quality at nearby wells and streams. For improving the management and protection of groundwater resources, it is important to first understand the various processes that control the transport of contaminants in groundwater. Predictions of the fate of groundwater contaminants can be made to assess the effect of these chemicals on local water resources and to evaluate the effectiveness of remedial actions. In this study, an attempt has been made to investigate the behaviour of solute transport through porous media using laboratory experiments. Sodium chloride was used as a conservative chemical in the experiment. During the experiment, pulse boundary condition and continuous boundary conditions were used. Experimental results have been presented for conservative solute transport in the sand. The pattern of the break through curve remains almost same in all the cases of varying flow rate and initial concentration of conservative chemical.