In an attempt to reduce nutrients in the nation's waterways, the U.S. EPA (Environmental Protection Agency) is setting water quality criteria which serve as recommendations to states and tribes for water quality standards for nutrients, including nitrogen and phosphorous. Using the new criteria, states are expected to adopt or revise their nutrient standards by 2004. In a 1998 water quality report to Congress, nutrients were listed as a leading cause of water pollution - excessive nutrients have degraded almost 3.5 million acres of lakes and reservoirs and over 84,000 miles of rivers and streams.