Edge-of-field monitoring stations provide information about the amount of runoff, soil, and nutrients moving off a given field into the waterway. Sites are fully automated to collect water samples whenever runoff occurs. Water samples are analyzed for nitrogen, phosphorus, and sediment and monitoring occurs year-round, 365 days a year. Monitoring has shown that 40 percent of the surface runoff occurs when the ground is frozen. Image courtesy of Kevin Kuehner, Minnesota Department of Agriculture.