Computer Modeling Vadose Zone Models Groundwater Flow Model Solute Transport Model

Vadose Zone Models Vadose zone models are used to quantify the amount of contaminant loading to the groundwater system The analytical or numerical models may be used (e.g., HYDRUS-1D) HYDRUS-1D simulates the one-dimensional movement of water and chemicals in unsaturated soil.

Groundwater Flow Model Groundwater flow will be simulated for the Groundwater basin(s) associated with the agricultural land of Vieques. Groundwater flow will be simulated using the numerical model MODFLOW Pre and post processing will be accomplished using GMS.

Model Development Spatial characteristics Grid design Initial conditions Boundary conditions Steady-state Transient

Model Development-cont. Model Calibration Steady-state Transient Sensitivity Analysis Model validation Particle Tracking

Solute Transport Modeling Identification of sites to be modeled Selection of contaminants to be modeled Solute transport model development Grid spacing and time step requirements Initial and boundary conditions Transport model calibration and sensitivity analysis

Surface Water Modeling Watershed Management System (WMS) ARCView Compatible User-friendly interface for creating numerical watershed models. Hydrologic System Program Fortran (HSPF) Simulates for extended periods of time the hydrologic, and associated water quality, processes on pervious and impervious land surfaces and in streams and well-mixed impoundments

Development of a Watershed Model

Evaluation of Remedial Alternatives No-Action Alternative Various alternative will be considered.

Reporting Periodic status report Final Report Publications and presentations at professional meetings Publications in peer reviewed journals