Nutrient pollution–primarily excess nitrogen and phosphorus–is the most widespread water quality problem facing the United States, with far-ranging consequences for environmental condition, economic prosperity, and human health and well-being. Nutrient loadings contribute to harmful algal blooms (HABs), hypoxia, fish kills, terrestrial biodiversity changes and degradation of drinking source waters that require costly water treatment. Despite progress to reduce nutrient loadings, these pollutants continue to be released and discharged at concentrations that cause adverse impacts to human health and aquatic and terrestrial ecosystems. Research is needed to better determine the appropriate spatial and temporal context for reductions and best practices for tracking interventions to meet nutrient reduction goals in a comprehensive manner.
EPA provides information, methods, tools, evaluation techniques, and best practices to address problems associated with excess nutrients. This work develops methods to determine nutrient-related impacts in watersheds and water bodies across multiple scales, quantifies ecosystem response and recovery rates, and helps to identify watersheds and water bodies that are optimally suited for management interventions. Additionally, assessment and management research provide models and tools that apply best practices for nutrient management, develops approaches to monitor the effectiveness of those management practices, and evaluate the efficacy of those actions using an integrated, socio-economic, multi-media approach.
This research helps inform decisions on how source water protection and other management options can be utilized to protect drinking water from nutrient contamination and provide decision makers with the resources to develop efficient and effectual watershed restoration strategies.
- Water Quality Impacts of Nutrients
- Nutrient Reduction Strategies
- Nutrient Restoration and Recovery
- Reducing Excess Nutrients Research Pilot
- HABs and Cyanobacteria
- HABs Monitoring and Remote Sensing
- Nitrogen Deposition and Nutrient Modeling
- Nitrogen Mapping
- Nutrient Management Case Studies
- Sustainable Watersheds and Nutrient Pollution
- Dimensions of Water Quality
- Cyanobacteria Assessment Network Mobile Application (CyAN App)
- Water Quality Analysis Simulation Program (WASP)
- Causal Analysis/Diagnosis Decision Information System (CADDIS)
- Global Change Explorer
- WATER, Soil, and Hydro-Environmental Decision Support System (WATERSHEDSS)
See EPA Science Models and Research Tools (SMaRT) Search for a full listing of available tools.
- Nutrients publications in Science Inventory
- Nitrogen or Phosphorus publications in Science Inventory
- Reports by other Agencies