Groundwater contamination can present health risks to humans and other ecological receptors. This book introduces the fundamental concepts and principles of contaminant movement in subsurface environments. It presents a quantitative approach and describes the mathematical tools and methods for assessing exposures and risks from groundwater-related transport pathways. The practical calculations necessary for analyzing slug test data will be included, as well as how to delineate groundwater plumes, estimate natural attenuation, and evaluate different remediation technologies. It also utilizes integrated R programming environments throughout the book for hands-on and practical engagement.