The compounds profiled include those herbicides, insecticides and fumigants most commonly found in the groundwater environment. The number of compounds included in this book was narrowed down based on information available in the documented literature. Compounds profiled in this book include pesticides having the potential for contaminating groundwater in New Jersey (Murphy and Fenske, 1987), compounds for which physicochemical data are available from the U.S. Department of Agriculture (1990) and those compounds which have been identified as organic Priority Pollutants promulgated by the U.S. Environmental Protection Agency (U.S. EPA) under the Clean Water Act of 1977 (40 CFR 136, 1977).