Discharges from facilities, with little to no treatment for nitrogen and phosphorus are a significant source of these nutrients to surface waters throughout the country. Setting permit limits and treating the wastewater to meet these limits can substantially reduce nitrogen and phosphorus loading from these facilities, protecting local and downstream water quality.

The data presented in the nutrient data tables are for major (≥1 million gallons/day (MGD)) and minor (<1 MGD) industrial and wastewater treatment facilities with individual, non-stormwater NPDES permits that, based on their classification and corresponding typical effluent nutrient concentrations, are likely to be discharging nitrogen and phosphorus.

The data tables are based on February 2016 data from EPA's Integrated Compliance Information System (ICIS) database.

See the protocol to learn how EPA constructed the nutrient data tables.

• Status of Nutrient Requirements for NPDES-Permitted Facilities (PDF)(4 pp, 1 MB)
• Protocol for Nutrient Pollution Data Compilation and Analysis (PDF)(18 pp, 1 MB)