Overview of the Toxic Substances Hydrology Program role in investigating the occurrence and fate of agricultural chemicals with links to investigations, headlines, on-line fact sheets, new publications, bibliographies and photo gallery.
Amphibian population declines and deformities due to various causes including land use change, viruses, and fungi. Links to USGS press releases, answers to FAQs (HTML and PDF versions) and photos with downloadable files.
Papers from a 1999 symposium on the possible effects on water resources and the environment of large agricultural feeding operations for pigs, chickens, and cattle, with links to other meetings, bibliography, and research studies. (Also as PDF files)
Information on arsenic in United States ground water largely as a result of minerals dissolving from weathered rocks and soils. Includes links to publications, data, maps, and links to other sites with information on arsenic.
Arsenic is a naturally occurring element in rocks, soils, and the waters in contact with them. It is found in ground water as the result of minerals dissolving from weathered rocks and soils. This site links to data, maps, and more.
The study of petroleum in both the saturated and unsaturated zones, to better understand the processes that control contaminant behavior, and to use this understanding to estimate the future behavior of the contaminants.