A Conceptual Site Model (CSM) is the basis for all site management decisions. If the CSM is wrong or incomplete the site management decisions will be negatively impacted. The CSM is dynamic, and is updated and improved throughout the lifecycle of the project. It is essential that the CSM be complete, accurate and robust in order to select, design and implement remedies that will meet remedial objectives in a cost effective manner.
A CSM is a useful tool to:
- Organize and communicate project information
- Identify and develop consensus about sources of uncertainty affecting decision-making
- Identify data gaps and means to develop data to reduce uncertainty
- Establish consensus understanding of site conditions
During site investigation and characterization, the CSM is a basis for:
- Determination of risks
- Identifying response actions including remedial technologies
- Establishing volumes requiring remedial action
- Identifying controls/limitations on remedial actions
- Setting realistic objectives/expectations for remedies
Many, if not most, remedies for subsurface contamination either underperform with respect to remedial objectives or even fail completely. These costly outcomes are nearly always the result of a mismatch between assumptions about subsurface conditions and actual subsurface conditions. A robust CSM is an essential tool for maximizing remedial success and minimizing cost.
Rather than being a recitation of facts or presentations of data, a CSM is an explicit set of hypotheses which describe the geology, hydrology and chemistry of the site. Specifically, they describe the interplay between them that controls not just contaminant transport and fate, but whether and how various remedial technologies will or won’t perform. The CSM is based both on site specific data and a state-of-the-science understanding of the systems at work in the subsurface. To the extent that the CSM is well thought out and tested, it is the single biggest tool at our disposal to help you save time and money on remediation projects.