Water is one of the primary means by which pollutants and toxins are transported. The San Luis Valley is a major agricultural area in which pesticides are used as a means of protecting crops. These pesticides can seep into wetland vegetation. However, just as water quality can effect wetlands, wetlands can improve water quality. Wetlands have become famous for their buffering ability.
Dense vegetation provides a filter for the polluted water.
Toxins and pollutants often are embedded in sediment and transported through ground water to a wetland. The vegetation allows the water to pass through the aquifer, but filters the pollutants on the sediment. The buffering ability of a wetland is controlled by stream power. The low hydraulic conductivity of wetland soils increases the buffering capacity of the wetland. The longer water takes to pass through the vegetation, the more efficient the filtering will be.