Influence of Wetland Hydrodynamics on Subsurface Microbial Redox Transformations of Nitrate and Iron

Background/Need:
Nitrogen (N) is a limiting nutrient in many aquatic ecosystems, particularly in estuarine and coastal marine environments. The anthropogenic N delivered in surface waters to coastal environments is a non-point source pollutant that originates primarily from agricultural activities. Thus, understanding controls on the transport and fate of N in inland waters is critical to maintaining the ecological health and economic viability of coastal resources. In addition to effects on ecosystems, nitrate contamination of groundwater is a well-documented problem throughout the world. In Dane County an estimated 30% of private wells contain nitrate concentrations that exceed drinking water standards.
Objectives:
This research sought to explore the interaction of nitrate and iron redox cycles in freshwater aquifers, a poorly understood but potentially significant influence on the fate of nitrate in the environment, through monitoring the geochemical and microbial properties of groundwater over
a one year period.