"We do not inherit the Earth from our ancestors; we borrow it from our children". Everyone should pay attention at the most important problems of our age. Problems concerning contaminants in the water, air, atmosphere are rising in the last years. For this, by means of Lattice Boltzmann models, the book focuses on the equations governing the status of these contaminants in the ground. A new way to investigate the phenomenas occurring at pore scale, needed to understand the macroscopic scale.