This data set provides the SEAWAT - version 4 model input files used to simulate the transport of the injected fresh wastewater with high levels of ammonia in a saline aquifer in south Florida, from January 1983 to December 2013. Initial conditions for January 1983 are calculated in subdirectory \model\unigrid_link where steady-state conditions are assumed. Files needed to simulate transient conditions from January 1983 to December 2013 are included in the \model\transient sub-directory. Executables needed to read simulated heads, normalized TDS concentrations, and ammonia concentrations from binary output files are provided to assist the user to generate times series of simulated values at each grid cell.