ABSTRACT
This chapter describes the role of the physical framework of the environment—its geology, hydrogeology, and geochemistry—in determining the fate and transport of chemicals. At the surface, chemicals are transported either through the air or by surface water. When transported in the air, the chemicals may be in solid, liquid, or gaseous phase. The materials in the subsurface generally fall into two categories: bedrock and soils. Bedrock consists of either igneous, sedimentary, or metamorphic rock. Igneous rocks originate from cooling magma that has welled up from deep within the earth’s crust, or from cooling lava from volcanoes at the surface of the earth. Dissolved chemicals and chemicals adhering to particles interact with other chemicals in the water, as well as with chemicals adhered to other suspended particles or the underlying sediments. Chemicals in the gaseous phase can travel much greater distances in air than in water.
