Nitrogen and Phosphorus Pollution

Nutrient pollution, especially from nitrogen and phosphorus, has consistently ranked as one of the top causes of degradation in some U.S. waters for more than a decade. Excess nitrogen and phosphorus lead to significant water quality problems including harmful algal blooms, hypoxia and declines in wildlife and wildlife habitat. Excesses have also been linked to higher amounts of chemicals that make people sick.

Basic Information

What is the problem?
What are EPA and the states doing?
- Status Report of State Criteria Adoption
What is EPA's National Nutrient Policy?
Glossary

What You Can Do

As an Individual
As Part of a Community
Potential Problems
Who to contact

What is the problem? An algal bloom is a rapid increase in the population of algae in an aquatic system.

Algal blooms are the result of an excess of nutrients (particularly phosphorus and nitrogen).

The bright green water in this estuary is result of a dense bloom of cyanobacteria. (Source: NOAA)

Algal blooms can present problems for ecosystems and human beings. What are EPA and the states doing?

Resources for Developing State Criteria

Criteria Documents
Criteria Development Guidance
- Nutrient Criteria Technical Guidance Manual: Wetlands
Implementation Frequent Questions
Online Technical Support for States