Environmental Health & Safety (EHS) Compliance
Environmental Studies & Permitting
Natural & Cultural Resources
Subsurface conditions create the greatest uncertainty when addressing complex contaminated groundwater sites. Project success directly hinges on a conceptual site model (CSM) that accurately assesses the geological heterogeneity and the preferential pathways imparted by it.
Our approach to CSM development begins with advanced analysis techniques applied to existing data. A key example of this strategy is Environmental Sequence Stratigraphy (ESS), an innovative approach for mapping subsurface conditions and contaminant distribution.
Because ESS has been shown to result in more predictable and cost-effective remediation strategies, through the use of stratigraphic interpretation methods originally developed and used in the oil and gas industry for decades, the technique has recently been adopted by the U.S. Environmental Protection Agency (EPA) and the U.S. Air Force as a best practice for developing CSMs for contaminated groundwater sites. ESS analyses produce a thorough and reliable foundation for remediation system design, an application particularly important for complex sites where high failure rates are common. An EPA Issue Paper describes how the geologic principles of ESS improve conceptual site models for complex contaminated groundwater sites.
Because ESS provides better definition of subsurface heterogeneity, it results in a CSM that more accurately depicts contaminant distribution and migration pathways — the “plumbing” that controls groundwater movement and contaminant transport. As leaders in the ESS field, we have co-authored a Technical Issue Paper recently published by the U.S. EPA. We can apply this established technique to all phases of groundwater remediation, helping you move your project to site closure in a more cost effective, predictable manner.
When appropriate, we also employ 3-D visualization modeling and other GIS and database tools to efficiently analyze site data and develop remedial strategies. Groundwater flow, contaminant fate and transport, and geochemical models can also be integrated to simulate multiple remediation approaches and accurately predict cleanup timeframes, costs and overall effectiveness.
In addition to subsurface conditions and remedies, our project teams incorporate other information critical to project decision making into the CSM. These include human health and ecological risk, surface features and site operations, and regulatory goals and parameters. An accurate and comprehensive CSM aids in the identification of unknown or hidden conditions and is critical to identifying elements driving the cost and schedule of a remediation project. With an improved understanding of the subsurface, significant surprises or protracted cost creep can be avoided.