- IGS Strategies: Hydrogeologic data from well installations, geophysics, and modeling can be used to develop groundwater flow models to more accurately define wellfield capture zones and prioritize areas for best management and conservation practices to reduce nitrate levels in public wells.
IGS hydrogeologists use the model to evaluate the extent of an aquifer, permeability and storage within an aquifer, groundwater flow direction and gradient, and sources of nitrate impacting a public water supply. With this information, IGS geologists can better define the extent of the groundwater capture zone, sometimes reducing it by as much as 90 percent. Improving capture zones allows targeting the installation of best management practices for improved long-term water quality.
For example, the IGS developed an accurate capture zone at Plainfield, Iowa, and convinced 100 percent of the landowners within the capture zone to use best management practices. Application of IGS research can significantly reduce nitrate concentrations in public drinking water supplies in a relatively short period of time.