Event mean concentrations for total phosphorus

Information: This page was updated October 31, 2019. Read table caption below.

Event mean concentrations for total phosphorus. This table was updated October 31, 2019. We retained data from the previous table, but we recommend using the median values from a literature review (3rd column). To see supporting information used to derive this table, link here.
Link to this table

Land cover/land use	Range (mg/L)	Recommended value (mg/L)1	Notes
Commercial	0.20 - 0.34	0.200	If applicable to models being used, adjust curve numbers/runoff coefficients when calculating loads
Industrial	0.23 - 0.55	0.235	If applicable to models being used, adjust curve numbers/runoff coefficients when calculating loads Adjust upward if specific phosphorus sources exist
Residential	0.26 - 0.38	0.325	Concentrations vary widely depending on local conditions
High-density/Multi-family residential	0.28 - 0.40	Calculate	Insufficient information to recommend a specific emc Concentrations vary widely depending on local conditions
Medium density residential	0.18 - 0.40	Calculate	*Insufficient information to recommend a specific emc Concentrations vary widely depending on local conditions
Low density residential	0.24 - 0.40	Calculate	Insufficient information to recommend a specific emc Concentrations vary widely depending on local conditions
Freeways/transportation	0.25 - 0.45	0.28	Concentrations vary widely depending on inputs Adjust upward for areas receiving large inputs of road salt or sediment or having very heavy traffic loads Adjust downward for low traffic areas or areas with reduced inputs (e.g. little road salt application, limited truck traffic)
Mixed	0.16 - 0.84	0.29	Residential land use was the primary land use in most studies that cited values for mixed land use
Parks and recreation		Use value for open space or calculate	emc will be a function of vegetative cover Adjust upward if street tree canopy cover is high or pervious areas are primarily grass on compacted soils
Open space	0.12 - 0.31	0.19
Conventional roof	0.01 - 0.20	0.030
Institutional	0.18 - 0.40
Cropland
Forest/shrub/grassland	0.03 - 0.25	0.07	Concentrations are likely to vary with season in areas with fall leaf drop
Open water
Wetlands
Farmsteads
Forest	0.05 - 0.25	0.25