• Journal of Soil and Groundwater Environment
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• v.27 no.spc
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• pp.1-18
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• 2022

A conceptual site model is used to support decision-making of response strategy development, determination, and implementation within a risk-based contaminated site management system. It aims to provide base information of the relevant site characteristics and surface/subsurface conditions in order to understand the contaminants of concern and the associated risk they pose to the receptors. This study delineated the technical details of conceptual site model development, and discussed the possibility of applying it in domestic subsurface contamination management. Conceptual site models can be developed in various formats such as tables, diagrams, flowcharts, and figures. Contaminated sites are managed for a long period of time following the steps of investigation, remediation design, remediation, verification, and post-remedation management. The conceptual site model can be enhanced in each stage of the contaminated site management based on the continuously updated information on the site's subsurface environment. In the process of enhancement for conceptual site model, precision is gradually improved, and it can evolve from a conceptual and qualitative form to a more quantitatvive and three-dimensional model. In soil pollution management, it is desirable to incorporate the conceptual site model into the soil scrutiny system to better assess the current status of the contaminated site and support follow-up investigation and management.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.85-88
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• 2001

Since mountainous area has access restrictions for field work, assessors need to establish a conceptual model of the contamination prior to the field investigation. In this study we established a conceptual model of the contamination based on site inspection and geological survey, followed by the field investigation for the petroleum spill site. In the conceptual model, we estimated that tile contamination should have spread by groundwater and topographical characteristics within the top soil layer. The spread of contamination through rock was not considered in the conceptual model due to impermeable characteristics of metasyenite. The contaminated environmental media of the petroleum spill site include soil and groundwater. According to the analysis result of the contamination, the volume of contaminated soil is estimated approximately 4, 150 cubic meters (7, 055 ton) with most contaminants existing along the groundwater flow within top soil layer.

• Journal of Soil and Groundwater Environment
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• v.25 no.2_spc
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• pp.28-54
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• 2020

Even though a systematic sampling approach is very crucial in both the general and detailed investigation phases to produce the best conceptual site model for contaminated sites, the concept is not yet established in South Korea. The U.S. Environmental Protection Agency (EPA) issued the 'Strategic Sampling Approaches Technical guide' in 2018 to help environmental professionals choose which sampling approaches may be needed and most effective for given site conditions. The EPA guide broadly defines strategic sampling as the application of focused data collection across targeted areas of the conceptual site model (CSM) to provide the appropriate amount and type of information needed for decision-making. These strategic sampling approaches can prevent the essential data from missing, minimize the uncertainty of projects and secure the data which are necessary for the important site-decisions. Furthermore, these provide collaborative data sets through the life cycle phases of projects, which can generate more positive proofs on the site-decisions. The strategic sampling approaches can be divided by site conditions. This technical guide categorized it into eight conditions; High-resolution site characterization in unconsolidated environments, High-resolution site characterization in fractured sedimentary rock environments, Incremental sampling, Contaminant source definition, Passive groundwater sampling, Passive sampling for surface water and sediment, Groundwater to surface water interaction, and Vapor intrusion. This commentary paper introduces specific sampling methods based on site conditions when the strategic sampling approaches are applied.

• Journal of Soil and Groundwater Environment
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• v.25 no.2_spc
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• pp.70-85
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• 2020

This paper introduces the 'Smart Scoping for Environmental Investigations Technical Guide' issued by the US Environmental Protection Agency in 2018, which describes the use of smart scoping during lifecycle of remedial investigation projects. This paper also briefly summarizes the guidelines of soil and groundwater contamination investigation of South Korea. The smart scoping practices can support the development of a robust and realistic conceptual site model that is very useful for investigations and evaluations of the contaminated site. The application of evaluation tools relevant for the site-specific characteristics is important for the development of a conceptual site model. The smart scoping recommends the use of previous investigation data and implementation of best proven strategies for successful remedial investigation project. The use of smart scoping in contaminated site investigation will provide better management of contaminated sites.

• Journal of Soil and Groundwater Environment
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• v.27 no.spc
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• pp.64-74
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• 2022

The conceptual site model (CSM) is used as a key tool to support decision making in risk based management of contaminated sites. In this work, CSM was applied in Jeonju Industrial Complex where site investigation for groundwater contamination was conducted. Site background information including facility types, physical conditions, contaminants spill history, receptor exposure, and ecological information were collected and cross-checked with tabulated checklist necessary for CSM application. The CSM for contaminants migration utilized DNAPL transport model and narrative CSMs were constructed for source to receptor pathway, ecological exposure route, and contaminants fate and transport in the form of a diagram or flowchart. The component and uncertainty of preliminary CSM were reviewed using the data gap analysis while taking into account the purpose of the survey and the site management stage at the time of the survey. Through this approach, the potential utility of CSM was demonstrated in the site management process, such as assessing site conditions and planning follow-up survey work.

• Journal of Soil and Groundwater Environment
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• v.28 no.2
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• pp.12-29
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• 2023

Conceptual site model (CSM) development and enhancement for contaminated sites assists in identifying data gaps during the site investigation process. In this study, CSM was developed and enhanced for a contaminated site in Korea as a case study. Site Y was scrutinized four times previously. The site profiles for each scrutiny were reorganized based on the scrutiny reports, and the relevant data was utilized to develop and enhance CSMs. CSM for the first investigation was developed in various forms including table, flowchart, diagram, and narrative formats. CSM was enhanced in a stepwise manner by incorporating the updated profile information obtained in next investigation to existing CSM. The hypothetical data gap analysis between each investigation step was established to meet the purpose of the follow-up investigation. This case study showed that CSM is a useful tool to identify the history and current status of contaminated sites and thereby help in planning supplementary investigations for better site characterization.

• Journal of Environmental Impact Assessment
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• v.20 no.3
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• pp.367-379
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• 2011

This study was conducted to develop an ecological park planning model to enhance the functions of habitats and ecological corridors in Green Belt Areas, because changing policies have resulted in the degredation of the Green Belts due to progressive fragmentation of ecosystems. The principal outcome of the study is to plan an ecological park model through the restoration of habitats. In order to evaluate the capacity of the model to enhance the ecological functions of habitats and ecological corridors in Green Belt Areas, a simulation of habitats was carried out in the Sungnam-Yusoo region. The model was developed via following steps: 1. Selection of candidate sites and selection of the study site by analyzing development factors; 2. Selection of target species that can represent the habitat at the site; 3. Analysis of the site's suitability index for the target species; 4. Establishment of a conceptual plan to enhance and expand the currently produced suitability index; 5. Creation of a master plan based on the conceptual plan; and 6. Evaluation of the enhanced and expanded suitability index of the site. The study showed that the Habitat Unit (HU) of Rana coreana, which was selected as the target species of the study, increased from $28,044m^2$(3.6%) to $224,352m^2$(28.8%), and the HU of the site as the ecological corridor for wild animals increased from $4,674m^2$(0.6%) to $152,684m^2$(19.6%). The study results show that the ecological deficits of the Green Belt Area can be overcome by enhancing the ecological functions of the region, which should be beneficial. The model could be utilized for effective enhancement and management of other Green Belt Areas.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.185-186
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• 2015

The Standard penetration test determines the type of soil according to soil bearing capacity, and this classifies the subsoil into many layers. Construction project managers are willing to know the depth of the present types of subsoil on site in order to make plans on earthwork stage during excavation. However the standard penetration test may not provide accurate information on subsoil type due to incorrect spacing. To solve this problem, this study propose a conceptual algorithm for determining the spacing of standard penetration test spots to essentially tests relevant locations on which to be applied the standard penetration test. This provides the acquirement of the accurate layered model volume of earthwork revised into geological columnar section. This algorithm will determine the appropriate standard penetration test spots spacing on a given size of site to optimize the accuracy of the earthwork volume, time and cost.

• Journal of the Society of Disaster Information
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• v.10 no.1
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• pp.15-24
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• 2014

The study presents work information classification system of apartment house which can organize all construction management services throughout the planning and management of a construction such as the decomposition of the design process, the assembly of construction process and cost estimating, etc. In addition, the study suggested a way to connect work information classification system based on a relational database in working order and built a conceptual model for automated cost estimating by utilizing established data base. A conceptual model for automated cost estimating will resolve the fundamental problems of the existing cost estimating system and will be able to take advantage of scientific cost estimating system at the construction site of apartment house.

• Journal of Soil and Groundwater Environment
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• v.25 no.1
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• pp.37-52
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• 2020

Sensitivity analysis of hydrodynamic and reaction parameters in conceptual model reflecting aquifer characteristics of Korea was performed to evaluate the uncertainty in the predicted concentrations. Among the hydrodynamic input parameters, both hydraulic conductivity (K_x) and hydraulic gradient (I) affected transport behaviors of contaminants, and resulted in same convergence concentrations with continuous injections of contaminant. However, longitudinal dispervisity (α_L) affected both transport behaviors and the convergence concentrations of contaminants. Compared to the hydrodynamic parameters, growth kinetic and degradation parameters (μ_m & K_c) more significantly affected both transport behaviors and the convergence concentrations of contaminants, indicating those parameters had higher sensitivity indices causing the uncertainties of model predictions. Considering that the sensitivity indices of both hydrodynamic and reaction parameters were a function of transport distance of groundwater, the parameters with higher sensitivity indices, a priori, need to be investigated using conceptual model reflecting site-specific aquifer characteristics before field investigation. After determining the parameters with higher sensitivity indices, the detail field investigations for the selected hydrodynamic and reaction parameters were warranted to reduce the uncertainties of model predictions.