What Factors Affect Ground-Water Flow and Chemistry?
Rates and pathways of ground-water flow, and the likelihood that ground water will be contaminated by nitrate, depend on a combination of factors. These factors include soil and aquifer composition, land use, and topography. The grain size of soil and aquifer sediment affects the rates and pathways of ground-water flow. Coarse-grained sediment forms permeable aquifers through which water readily flows. Fine-grained sediment forms low-permeability aquifers (and confining units) that retard ground-water flow. The amount of organic material in soil and aquifer sediment affects water chemistry. The amount of organic material generally is minimal in coarse-grained sediment and tends to be more abundant in fine-grained sediment. Organic material reacts with dissolved oxygen, removing it from the water. In areas where organic material is abundant, dissolved oxygen can become rapidly depleted. Soil composition, topography, and land use commonly reflect the factors that affect ground-water flow
