ABSTRACT We looked at methods of interpolation for calculating the hydraulic head contour lines from wells located throughout a region. One method we chose to investigate was a relaxation or finite-difference method. This method required that the hydraulic heads be located on a square grid and can be derived using elementary numerical analysis. An initial guess was made for the unknown hydraulic head values, and then passes were repeatedly made through the grid to determine the unknown head values. The calculations were done using a spreadsheet. Ten methods of initializing the data were tested that simulate varying boundary and interior date conditions. The resulting hydraulic head values were then used to create hydraulic head contour maps in Maple. We also obtained data from sites in New Jersey from the NJ Department of Environmental Protection Division of Hazardous Site Mitigation and ran our model on this data.