Step 2: Spill Percolates Through Soil
The contaminant seeps downward and begins to disperse in the aquifer. The contaminant now has formed a contaminant plume.
All contaminants are affected to some extent by the flow of groundwater, which slowly causes the contaminant to spread out into a plume. The plume is the path in which the contaminants are moving through the aquifer. The size of the plume will vary with the physical and chemical nature of the contaminant(s) and the aquifer (see Step 3).