S.S. Papadopulos & Associates, Inc software

S.S. Papadopulos and Associates. Inc., in collaboration with the University of Waterloo, has developed a powerful, state-of-the-art particle tracking software for groundwater models with unstructured grids. Armed with high-order Runge-Kutta ODE solvers and multi-threading support, mod-PATH3DU is the most powerful particle tracking program available for MODFLOW and MODFLOW-USG.

DECAY is an analytical solution for one-dimensional transport of multiple species along a decay chain with branching. The treatment of branching accommodates species potentially having more than one parent and species having more than one daughter product. The DECAY solution considers advection, dispersion, equilibrium sorption, and first-order straight-chain and branching decay reactions. The species may have different dispersion and sorption coefficients. The solution accommodates the specification of different decay rates for the dissolved and sorbed phases for each species. Yield coefficients can be specified so that the calculations can be conducted in terms of concentrations expressed in units of either mass or moles per unit volume of water. The DECAY solution allows Dirichlet and Cauchy inflow boundary conditions with Bateman-type source histories.

Excel implementations of analytical solutions for one-dimensional transport of solutes in groundwater.

A set of steady-state analytical solutions of groundwater inflows to open excavations is assembled. The solutions are appropriate for developing preliminary estimates of long-term rates of groundwater flows into open excavations.

Groundwater Desktop (GWD) is a fully 3D interface for visualizing groundwater models and their results. While GWD is flexible and might be used to visualize any model, development to-date has focused on MODFLOW, MODPATH, and MT3D, including the latest unstructured grid capabilities within MODFLOW-USG. GWD enables users to view the model numerical grid, input data such as properties and boundary conditions, and output data including heads, concentration, and pathlines. Models can be examined using cross-sectional, cut-away, and layer "exploded" views. rogram for MODFLOW.

ATRANS A 3D analytical solution for transport from a patch boundary condition with time varying concentration.

MT3D99 - The Leading Code for Analyzing Contaminant Migration in Groundwater. MT3D99 builds on the strengths of the public-domain MT3DMS code, and includes significant new enhancements to improve performance and increase the functionality of the MT3D96 and MT3DMS codes.

PATH3D V4.6 is a powerful and widely used particle-tracking program for MODFLOW.

MPNE1D A General Analytical Solution for One-Dimensional Solute Transport. MPNE1D is a FORTRAN90 code that implements the general analytical solution for one-dimensional solute transport.

BIOSCREEN-AT is a screening-level model developed for and distributed by the EPA that simulates remediation through natural attenuation of dissolved hydrocarbons at petroleum fuel release sites.