Information: This page contains information on event mean concentrations for phosphorus and suspended sediment derived from the National Stormwater Quality Database. This data was updated in March, 2020, and we include the updated information and the table with the older information. We recommend using the updated table or data contained in this table, which provides a more comprehensive and up-to-date summary for event mean concentrations.

Event Mean Concentrations of pollutants in stormwater runoff by land use. Source: National Stormwater Quality Database.
Link to this table

Updated Table

Land use Phosphorus EMC (mg/L) TSS EMC (mg/L)
Median Count Std dev Median Count Std dev
Commercial 0.0.11 165 0.144 97 164 168
Industrial 0..22 165 0.287 70 84 108
Open space 0.19 6 0.063 38 6 17.2
Residential 0.27 249 0.380 92 250 166


Old Table

Land use Phosphorus EMC (mg/L) TSS EMC (mg/L)
Low Medium High Low Medium High
Commercial 0.15 0.25 0.35 120 140 160
Industrial 0.15 0.25 0.25 130 150 170
Institutional 0.15 0.25 0.35 100 120 140
Multi-use 0.3 0.4 0.5 120 140 160
Municipal 0.2 0.3 0.4 120 140 160
Open space 0.1 0.2 0.3 70 90 110
Residential - high density 0.3 0.4 0.5 120 140 160
Residential - low density 0.4 0.5 0.6 130 150 170
Residential - medium density 0.2 0.3 0.4 100 120 140
Transportation 0.3 0.4 0.5 115 135 155

This page was last edited on 26 January 2023, at 12:58.