This is the core course for new graduate students in environmental chemistry, and provides an introduction/refresher to concepts from physical, analytical and organic chemistry and their application to the environment. It also provides you with the background to better understand the research of your peers and colleagues. Topics include: Introduction to the physical environment and relevant timescales, chemical kinetics, photochemistry, gas and aqueous phase reaction mechanisms, chemical thermodynamics, phase partitioning, sorption of organic contaminants to soils and sediments, analytical methods of characterization.