Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

► Watershed densities of animal feeding operations (AFOs) were calculated for small streams. ► In-stream nutrient concentrations were directly related to watershed densities of AFOs. ► In-stream estrogenic activity was also directly related to watershed densities of AFOs. ► Municipal effluent only increased phosphorus concentrations in the studied streams.