From the dataset abstract

Door County, the narrow peninsula in eastern Wisconsin, is home to numerous wetlands, many of which are fed by groundwater. Poor-quality groundwater discharging to a wetland can alter the ecology of the wetland and harm native plant and animal communities. This report documents a one-year study of six wetlands. Researchers recorded water quality and quantity discharging to each wetland and linked surrounding land use to contaminants. Data collected during the study are available for download.

Source: Water-Quality Indicators of Human Impacts to the Wetlands of Door County, Wisconsin