section 1. Introduction to groundwater geochemistry and fundamentals of hydrogeochemical modeling -- Hydrogeochemistry principles for geochemical modeling / J. Bundschuh & O. Sracek -- Thermodynamics of gas and mineral solubility in the unsaturated zone water / L. Mercury & M. Zilberbrand -- Governing equations and solution algorithms for geochemical modeling / C. Ayora, M.W. Saaltink & J. Carrera -- Fluid flow, solute and heat transport equations / M.W. Saaltink, A. Yakirevich, J. Carrera & C. Ayora -- Numerical solutions of reactive transport equations / M.W. Saaltink, J. Carrera & C. Ayora -- Elaboration of a geochemical model / M. Zilberbrand -- Advances in geochemical modeling for geothermal applications / P. Birkle -- section 2. Case studies -- Integrating field observations and inverse and forward modeling : application at a site with acidic, heavy-metal-contaminated groundwater / P. Glynn & J. Brown -- Models and measurements of porosity and permeability evolution in a sandstone formation / S. Emmanuel, J.J. Ague & O. Walderhaug -- Geochemical modeling of water chemistry evolution in the Guarani Aquifer System in Sao Paulo, Brazil / O. Sracek & R. Hirata -- Modeling of reactive transport at a site contaminated by petroleum hydrocarbons at Hnevice, Czech Republic / O. Sracek & Z. Vencelides -- Numerical modeling for preliminary assessment of natural remediation of phosphorus in variably saturated soil in a peri-urban settlement in Kampala, Uganda / R.N. Kulabako, R. Thunvik, M. Nalubega & A.L. Soutter.