Presentation describing uses of rare earth elements, why they are important, where they occur and are produced, and aspects of the economics of production and consumption with emphasis on sites that might be developed for production.
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.
Explains the natural and human-affected factors that determine the concentration of contaminants in groundwater, especially where the concentration is different at the surface than at depth, and where pumping varies with time.
Explains what biochar is and how it is formed, its potential use in both fertilizer and carbon sequestration, and some of the research questions remaining to be addressed before we can utilize it fully in practical ways.