This publication includes peer-reviewed manuscripts from the 2009 International Network of Environmental Forensics (INEF) held in Calgary, Canada on August 31 through September 1, 2009. INEF is an organization founded by environmental forensic scientists for the express purpose of sharing and disseminating environmental forensic information to the international scientific community. Environmental forensic information presented at the Calgary conference included topics on contaminant age dating, chemical biomarkers, environmental statistics, the interpretation of forensic data, emerging analytical techniques used in forensic investigations, legal sampling and strategies, petroleum hydrocarbon fingerprinting and diagnostic markers used to age date chlorinated solvents. All of these topics were presented in the context of using these techniques to ultimately identify the origin and age of contaminants released into the environment. This professionally edited book is the first of a series of conference publications chronicling the current state of the art in environmental forensics. The intent of this publication and subsequent INEF conference volumes is to compile a library of state-of-the-art scientific articles dealing with environmental forensic topics.