Mark E. Byrnes, RG, RHG, HS-PMP, is a senior environmental scientist and project manager working for the Central Plateau Cleanup Company at the Hanford Nuclear Reservation, where he is responsible for the groundwater characterization of one of the largest chlorinated solvent plumes in the world. Mark has over 30 years of experience overseeing the design and implementation of statistical and nonstatistical environmental sampling programs to support site characterization, waste characterization, risk assessments, feasibility studies, and remedial designs. He received his Master of Science degree in geology/geochemistry from Portland State University (Oregon), and his Bachelor of Arts degree in geology from the University of Colorado (Boulder). Mark is a registered geologist and hydrogeologist in the State of Washington. He is the author of the earlier 2009 and 1994 editions of this book which have been used as textbooks at many universities across the country, including Georgia Institute of Technology. He is also the author of the 2003 Lewis Publishers book titled Nuclear, Chemical, and Biological Terrorism: Emergency Response and Public Protection, and the 2001 Lewis Publishers book titled Sampling and Surveying Radiological Environments.