The latest update to EPA’s National Rivers and Streams Assessment does not paint a pretty picture of water quality across the U.S. The updated report, based on 2008 and 2009 data, finds that 46 percent of the nation’s river and stream miles “do not support healthy populations of aquatic life largely due to phosphorus and nitrogen pollution and poor habitat conditions.” While the study largely focuses on ecological factors of impairment, the major causes of pollution identified – phosphorous and nitrogen – continue to be a major concern for water utilities as they deal with nutrient pollution directly or with the algal blooms and potential algal toxins produced in such conditions.