Rationale for Selecting MODFLOW-SURFACT™

Key Discriminators of  MODFLOW-SURFACT™
Worldwide Acceptance
 MODFLOW-SURFACT™ has been licensed nationwide in the U.S. and worldwide in over 50 countries.
Modeling results have been accepted by state and federal regulators for planning, design, and implementation of remedies.
Full Capabilities & Rigorous QA/QC Documentation
Single code with full integration of flow and transport modules offering convenience and avoiding input/output error in conducting transient and density- dependent simulations. 
Includes a wide variety of flow and transport simulation capabilities for all levels of site complexity.
Comes with a fully documented user’s manual that has been subjected to rigorous quality assurance/quality control (QA/QC) and includes a full suite of example problems.
Ease of Use, Flexibility, and Computational Robustness
Offers compatibility with well-recognized, industry standard graphical user interfaces (GUIs) and has been well tested on a wide range of simulation capabilities.
Utilizes structured block-centered rectangular grids (in preference to the unstructured grid (MODFLOW-USG) approach with separate flow and transport packages) to offer an intuitive approach for entering model information and efficiently debugging problems (without unnecessary frustration) and to accommodate grid refinement for sub-models using telescopic mesh refinement (TMR) to target specific areas.
Provides robust and efficient matrix solvers, including the PCG5 solver developed by Dr. Peter Forsyth at the University of Waterloo, that allow large-scale simulations with millions of nodes in serial or in parallel on PC clusters or via a Cloud platform.
Credible Technical Support Team
Offers the support of an integrated technical support team with recognized experts in model development, GIS application, parameter estimation, calibration, sensitivity and uncertainty analysis, and 3-D visualization.
Led by Dr. Varut (Dua) Guvanasen, HGL Principal Engineer with extensive modeling experience, Professional Engineer (P.E.) license and Engineer of Record (EOR) qualifications, the HGL integrated technical team has established a strong record of customer satisfaction over the last two decades.
Capabilities for Extended Applications
Provides capability to perform integrated hydrologic model (IHM) simulations via direct linkage to MODHMS®.
Provides capability to perform multiphase flow and transport simulations via direct linkage to CompFlow.  
Provides capability to perform contaminant plume boundary delineation and optimization of monitoring well network via direct linkage to PlumeSeeker™.
Provides capability to perform computational optimization of  groundwater remedial system design and operation via direct linkage to PBMO™.
Provides specialized decision support capability for PFAS response and stakeholder interaction by being an essential component of PFAS-DSS.