Having originally defined the Environmental Geology course, this text is considered the most comprehensive yet readable book for a course at this level. Keller continues to offer the most detailed, current research available. He covers a wide range of topics, discussing everything from fundamental geologic principles to the specifics of environmental law and geologic hazards, from a truly environmental perspective. The Ninth Edition emphasizes the engineering geology approach, with more quantification of relationships, especially in the discussion of soil and rock mechanics and landslides.