A recent U.S. Geological Survey (USGS) report claims that elevated concentrations of nitrogen and phosphorus have remained the same or increased in many streams and aquifers across the United States since the early 1990s. Neil Dubrovsky, et al., “The Quality of Our Nation’s Water: Nutrients in the Nation’s Streams and Groundwater, 1992-2004,” USGS (September 23, 2010). The report’s results, based on 24,000 water samples taken between 1992 and 2004 from more than 500 bodies of water, led USGS to conclude that “widespread concentrations of nitrogen and phosphorus remain two to ten times greater than levels recommended by EPA to protect aquatic life.”
USGS recommends (i) developing nutrient criteria for surface water bodies, (ii) reducing nutrient loadings to receiving waters, (iii) setting realistic expectations for water-quality improvements following nutrient reduction strategies, and (iv) managing elevated nutrients in drinking water from surface-water intakes and wells. The report includes graphics, tables and nutrient data.