This book discusses the practical application of numerical groundwater flow and reactive solute transport modeling of sequential biodegradation of chorinated solvents at a site in Palm Bay, FL. The dissertation presented in this book is the first multi-species numerical model calibration to a unique site with large amounts of data collected from over 200 wells over a 20 year period. The groundwater model MODFLOW and solute transport model MT3D99 were calibrated to remediation over a 20 year period. Results of modeling analyses showed that groundwater pumping played a key role in source zone remediation with natural biodegradation being the primary mechanism for removing downgradient contaminant mass from the aquifer. The estimated natural biodegradation half lives for trichloroethene (TCE), cis 1,2 dichloroethene (DCE), and vinyl chloride (VC)were 550 days, 480 days, and 590 days at this site. Subsequent data has confirmed the presence of the Dehalococcoides Ethenogenes, which are currently the only known microbes that can biodegrade TCE and its biodegradation products (cis 1,2 DCE and VC).