A database for surface impoundments (SIs) consisting of hydrogeologic and operational parameters was developed and statistically analyzed. The database was used to evaluate infiltration, groundwater mounding, contaminant transport (dilution), and the relationships between each of these mechanisms. Analytical, numerical, and statistical solutions were used for the evaluation. Hydraulic heads calculated with Hantush's analytical solution for mound growth compared well to those computed by a two-dimensional numerical transport model for unconfined aquifers (UNMOC). Infiltration from the "typical" surface impoundment (defined by the database) was modeled with UNMOC. Dilution effects were quantified and compared to those predicted by the one-dimensional Monte Carlo model (EPACML) used by EPA in specifying acceptable waste concentrations for disposal. The SI-specific database in conjunction with UNMOC predicted much less dilution than EPACML and provide an alternative approach to regulating surface impoundments.