Water Quality - Hydrogeology: Objectives, Methods, Applications - page 92

Figure 49 Transfer of a contaminant downslope.

Figure 50 Pollution plume downslope of a landfi ll.

• fi nally, the mass of contaminant in the hydrosystem can decrease,

- in the best case scenario, the contaminant degrades into a non-toxic

compound through physical or chemical reactions, or through
microbial attack. For example, nitrates in a confi ned aquifer can
be reduced to non-reactive nitrogen gas.