National Stormwater Quality Database-derived event mean concentrations for phosphorus and TSS National Stormwater Quality Database-derived event mean concentrations for phosphorus and TSS

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