Geosyntec provides public and private clients a range of services for their toughest challenges, including contaminated media investigations, feasibility studies and remediation system designs, subsurface vapor intrusion mitigation, environmental forensic studies — and much more.
Many of our most successful contaminated site assessments and cleanup services include the creation of a conceptual site model (CSM). These models range in size and complexity but frequently provide key stakeholders with a solid framework for understanding the challenges posed by a particular site. Armed with the clarity of data, narrative descriptions, and graphic visualizations of various impacts presented by our CSMs, decision makers frequently find they are better able to choose courses of action that expedite restoration efforts, provide superior results, and deliver significant cost savings during the course of remediation.
Geosyntec's CSMs take many forms, but in broad terms they can be either written or visual documents, reports, graphics, or 3- and 4-D visualizations that represent the conditions and the physical, chemical, and biological processes that control the transport, transformation, and potential impacts of contaminants in soil, air, groundwater, surface water, and sediments. They also help identify human and ecological exposure pathways that may be present at an impacted site.
Our CSMs are objective-driven and designed to support the data quality objectives (DQO) process that provides defensible data and supports robust decision-making. They also aid clients in their efforts to communicate effectively with interested parties about the critical issues or processes identified at the site. On many occasions, our CSMs are used to inform members of the public or government officials how the client plans to effectively address any impacts that may affect the community or bring an impacted site into compliance with regulatory requirements. Geosyntec practitioners are cognizant of best-practice guidance and adopt practices that meet the specific regulatory frameworks for the preparation and submission of CSMs.
Additionally, our CSMs are iterative tools. A CSM developed by Geosyntec practitioners generally begins with the collection of existing data on impacted sites, which might include historical records, earlier surveys and sampling data, site operating records, aerial photographs, maps, and the like. We then organize and analyze known sources of contamination and potential contaminants. We also identify potentially contaminated areas and affected media and locate potential migration routes, exposure pathways, and receptors. Typically, site investigations then begin to confirm our initial data and identify any gaps in the information. We update CSMs as projects proceed to a level of detail that matches the complexity of site conditions and the availability of data.
An important stage in the development of a CSM is the identification of crucial processes that influence contaminant transport, transformation, and response to remedial treatment. Quantifying these processes demands the development of a mathematical model, where the governing equations are solved through the use of analytical or numerical techniques. Our personnel have used a wide range of analytical and numerical modeling software to predict plume migration and response to pumping wells, interceptor trenches, cutoff walls, source removal, retardation/attenuation, and other physical/chemical/biological effects. Many of the models that we use involve 2-D and 3-D finite difference or finite element computer codes. However, at certain sites, we have successfully used simpler models, including 1-D or 2-D analytical solutions.