How do factors such as the groundwater flow system, geochemical condition, groundwater age, and depth of the aquifer affect the concentrations of nitrate in groundwater?
Concentrations of nutrients, especially nitrate, in groundwater are the result of nutrient inputs and natural conditions that favor transport. In addition, understanding the concentrations of nitrate in groundwater usually requires an understanding of the groundwater flow system, geochemical conditions (redox), the groundwater age, and the depth of the aquifer (well depth). Key natural factors, including soil type and geology, can govern the amount and timing of transport of nutrients to groundwater. The amount of groundwater that can flow through soils and geologic formations or the “groundwater flow system” primarily depends on permeability (the size and arrangement of the connected spaces in the materials that comprise the formation). For example, nitrate is typically lower in aquifers with impermeable soils and bedrock than those with permeable soils and (or) bedrock because, among other things, groundwater moves more slowly in the former case. Thus, groundwater may take years to d
