Despite major Federal, State, and local efforts and expenditures to control the sources and movement of nutrients within our Nation's watersheds, national-scale progress was not evident in this assessment, which is based on thousands of measurements at hundreds of study sites from across the country from the 1990's. (Matthew C. Larsen, USGS Associate Director for Water). Full study details: http://water.usgs.gov/nawqa/nutrients/pubs/circ1350/