Groundwater Modeling Software
  
SSP&A is a recognized leader in the development of groundwater modeling software. The most widely used groundwater contaminant transport model, MT3D, and the most versatile particle-tracking model on the market, PATH3D, were developed by SSP&A staff. Steven Larson, a principal at SSP&A, was the co-author of the U. S. Geological Survey's groundwater flow model, "Finite-Difference Model for Simulation of Three-Dimensional Ground-Water Flow."

A description of the major programs, developed and marketed by SSP&A, is provided below. Additional information on all available SSP&A software is available  HERE >

MT3D

MT3D, a general-purpose groundwater transport model, is the world's most popular solute transport code. MT3D was developed by SSP&A because easy-to-use, three-dimensional groundwater transport models were not available from other sources. The model is well-documented and tested for three-dimensional groundwater transport. MT3D is based on a particle tracking scheme and is implemented for use in conjunction with the U. S. Geological Survey's MODFLOW program. The model is structured in a modular format and is designed to simulate advection, dispersion, sink/source mixing and chemical reactions, including sorption, radioactive decay and biodegradation. Additional transport processes can be added without having to modify the existing code. MT3D uses a mixed Eularian-Lagrangian approach to the solution of the three-dimensional advective-dispersive-reactive equation and is suitable for a wide range of field problems.

SSP&A has marketed MT3D since 1989 and copies have been sold to groundwater modelers around the world. SSP&A maintains a network of MT3D users, distributes software updates for the program, and distributes the quarterly newsletter, MT3D News, to owners of the software.

PATH3D

PATH3D  is a general particle-tracking program which calculates groundwater flow paths and travel times in transient three-dimensional flow fields. The program can be used to simulate the movement of groundwater flow and the advection of contaminant solutes in groundwater. The program is particularly useful for delineating contaminant capture zones or well-head protection zones in order to evaluate the effectiveness of groundwater pollution control under complicated hydrogeological conditions. PATH3D can serve as a valuable extension to groundwater flow models which in themselves do not provide quantitative information on flow paths and travel times, or as a practical alternative to contaminant transport models in cases where they are not feasible due to budget constraints or the lack of chemical data.