“Use of SPARROW models to Determine the Spatial Distribution and Sources of Nutrients in Streams throughout the Great Lakes and Mississippi River Basins” will be the topic of a seminar scheduled for 11 a.m. Friday, Sept. 16, in Room 216 McNutt Hall. The speaker will be Dr. Dale M. Robertson, a research hydrologist in surface-water chemistry at the U.S. Geological Survey’s Wisconsin Water Science Center. The seminar is presented by the Environmental Research Center.