Fate and Transport (F&T) Modeling for Remedial Design

XDD personnel have over 30 years of experience in transport and remediation modeling to evaluate cost-effective remedial strategies for impaired properties. Using a fundamental understanding of the core physical, chemical and biological principals governing groundwater and vapor flow and the transport of contaminants, XDD has developed simulations using EPA approved models to simulate contaminant fate and transport in groundwater, soil, and soil vapor, saving our clients both valuable time and resources in the process of achieving their project goals.

Vadose Zone Airflow and Transport

XDD Environmental has developed various defendable vadose zone simulations using standard industry transport models to aid in the design of active remedial solutions and evaluate the transport of impacts for both human and environmental receptors. Our decades of experience with soil vapor extraction and air injection technologies gives us a unique understanding of transport mechanisms in the vadose zone that other companies cannot bring to the table. XDD uses modeling software to aid in understanding:

  • Site air permeability
  • Distribution vacuums/pressures/flows for different remedial designs
  • Expected air exchanges for a soil vapor extraction design
  • Potential time required to meet remedial design requirements

Whether the question revolves around potential impacts to indoor air, groundwater, or the anticipated design and costing of an active remedial solution, XDD’s experience benefits our clients.

Groundwater Flow and Transport Modeling

Contaminant fate & transport modeling is often an integral part of XDD’s process for developing cost-effective remedial strategies for impaired properties. XDD has assisted both our partner consultants and end-users by designing and evaluating groundwater models of varying sophistication, depending upon the project needs. Our simulations and visualization capabilities have been used to assist with:

  • CERCLA level feasibility evaluations
  • In situ chemical oxidation/reduction injection technologies
  • Screening level fate and transport determinations
  • Post-remedial benefit evaluations

Transport Modeling Tools

XDD’s understanding of the advantages and disadvantages of the following industry accepted modeling packages has helped guide our clients to understand the risk and evaluate remedial options for impacted properties:

  • Vadose:
    • SESOIL
    • VLEACH
    • VS2DI
    • AIR3D
    • Johnson & Ettinger Model for Subsurface Vapor Intrusion into Buildings
    • Proprietary Vadose Zone Modeling to Evaluate Airflow Distribution in complex geologic environments
  • Groundwater:
    • Groundwater Modeling System (GMS)
    • MODFLOW
    • Modflow, MT3DMS, RT3D and Modpath
    • BIOSCREEN
    • BIOCHLOR
    • PHREEQC