Experiments in which stable, easily detected substances or radioisotopes are added to a material to follow the movement of the substance in the environment or to detect any physical or chemical changes with time.
Overview of chemical analyses, tracer studies, gas geochemistry, stable isotopes analyses, organic chemistry, and thermometry capabilities at major USGS laboratories with links to technique, equipment, and contacts for each procedure.
Overview of fractured rock research aimed at understanding the movement of water through fracture networks, and characterize field conditions influencing contaminant migration. Includes programs and publications.
A guide to measuring the flow of water across the ground water surface water interface, with an overview of available methods and details of specific methods to use.