Stormwater event mean concentrations and pollutant loading/export rates for different land uses Stormwater event mean concentrations and pollutant loading/export rates for different land uses

For a discussion of event mean concentrations, see Stormwater pollutant concentrations and event mean concentrations

Event mean concentrations for total phosphorus

For a discussion of event means concentrations for phosphorus, see Event mean concentrations of total and dissolved phosphorus in stormwater runoff

Event mean concentrations for total phosphorus.
Link to this table

Land cover/land use	Range (mg/L)	Recommended value (mg/L)	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	Calculate1	Insufficient information to recommend a specific emc Concentrations vary widely depending on local conditions
Medium density residential	0.18 - 0.40	Calculate1	Insufficient information to recommend a specific emc Concentrations vary widely depending on local conditions
Low density residential	0.24 - 0.40	Calculate1	Insufficient information to recommend a specific emc Concentrations vary widely depending on local conditions
Freeways/transportation	0.25 - 0.45	0.280	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	0.290	Residential land use was the primary land use in most studies that cited values for mixed land use If the study area can be delineated into specific land uses and impervious area for each land use is know, we recommend calculating the emc
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	0.190
Conventional roof	0.01 - 0.20	0.030
Institutional	0.14 - 0.422	See note	Use low values in range (0.200 mg/L or less) for facilities such as campuses, where there is considerable pervious area Use high values in range (0.30 mg/L or greater) for areas with considerable impervious surface, such as sports facilities or facilities with large parking areas
Forest/shrub/grassland	0.03 - 0.45	0.090	Concentrations are likely to vary with season in areas with fall leaf drop
Open water and wetlands		see Notes (next column)	If data exist, use the phosphorus concentration for the water body of interest If data for a specific lake do not exist, use data from similar lakes in the area emcs for wetlands will typically be higher than for lakes in an area. Consider using a value equal to 2 times the value for lakes in an area.
Cropland (row crops)	0.126-1.348	2	Median from our review = 0.533
Pasture	0.35-0.45	2

¹The link takes you to information on calculating event mean concentrations for areas with multiple land uses.
²Our literature review was not extensive enough to warrant a specific recommend emc for this land use

Event mean concentrations for dissolved phosphorus

For a discussion of event means concentrations for phosphorus, see Event mean concentrations of total and dissolved phosphorus in stormwater runoff

Summary of dissolved phosphorus event mean concentrations from various studies. There is inadequate information to provide recommended emcs for different land uses.
Link to this table

Study	Land cover/land use	Range (mg/L)	Mean	Median	Number of samples
Dallas-Fort Worth1	Commercial	0.01-0.47	0.09	0.06	42
Dallas-Fort Worth	Industrial	0.03-0.45	0.14	0.09	63
Dallas-Fort Worth	Residential	0.04-0.84	0.25	0.21	77
Forth Worth2	Transportation			0.11	28
Twin Cities3	Mixed	0.01-1.4	0.2	0.15	147
Madison4	Medium density residential		0.52	0.61	25
Madison4	Medium density residential		0.4	0.14	25
Madison4	Medium density residential		0.14	0.04	25
Madison4	Medium density residential		0.05	0.03	25
Madison4	Medium density residential		0.04	0.02	25
Madison4	Medium density residential		0.03	0.02	25
Madison4	Medium density residential		0.04	0.02	25
Madison4	Medium density residential		1.54	0.81	25
Madison4	Medium density residential		0.12	0.08	25
Madison4	Medium density residential		0.11	0.07	25
Madison4	Medium density residential		0.11	0.07	25
US EPA Nurp Study5	Residential			0.143
US EPA Nurp Study5	Mixed			0.056
US EPA Nurp Study5	Commercial			0.08
US EPA Nurp Study5	Open			0.026
New York6	Residential		0.20		738
New York6	Commercial		0.18		323
New York6	Industrial		0.16		325
New York6	Open		0.16		44
Capitol Region Watershed District7	Mixed	0.020 - 0.888	0.073	0.052	89
Capitol Region Watershed District7	Mixed	0.020 - 0.565	0.108	0.087	120
Capitol Region Watershed District7	Mixed	0.020 - 0.506	0.074	0.059	112
Capitol Region Watershed District7	Mixed	0.020 - 0.361	0.073	0.053	121
Capitol Region Watershed District7	Mixed	0.005 -- 0.182	0.019	0.012	195
Capitol Region Watershed District7	Mixed	0.020 - 0.758	0.102	0.072	69
Capitol Region Watershed District7	Mixed	0.020 - 1.10	0.072	0.053	115
Capitol Region Watershed District7	Mixed	0.020 - 0.60	0.099	0.057	113
Capitol Region Watershed District7	Mixed	0.020 - 0.499	0.071	0.046	138

¹Urban Stormwater Quality, Event-Mean Concentrations, and Estimates of Stormwater Pollutant Loads, Dallas-Fort Worth Area, Texas. 1992–93 Stanley Baldys III, T.H. Raines, B.L. Mansfield, and J.T. Sandlin U.S. Geological Survey Water-Resources Investigations Report 98–4158.
²Computed and Estimated Pollutant Loads, West Fork Trinity River, Fort Worth, Texas, 1997. United States Geological survey. Water Resources Investigations Report 01–4253
³Brezonik and stadelman. 2002. Analysis and predictive models of stormwater runoff volumes, loads, and pollutant concentrations from watersheds in the Twin Cities metropolitan area, Minnesota, USA. Water Research Volume 36, Issue 7, Pages 1743-1757
457.Waschbusch, R.J., W.R. Selbig, and R.T. Bannerman. 1999. Sources of phosphorus and street dirt from Two Urban Residential Basins in Madison, Wisconsin, 1994-95. USGS Water-Resources Investigation Report 99-4021
⁵U.S. EPA. Results of the Nationwide Urban Runoff Program. 1983. Volume I: Final Report. PB84-185552
⁶New York State Department of Environmental Conservation. August 2003. Stormwater Management Design Manual. Chapter 5 - Acceptable Stormwater Management Practices.
⁷Outfall monitoring data for Villa Park, Trout Brook East, Trout Brook West, Trout Brook Outlet, St. Anthony, Phalen Creek, Como 3, Como 7, and East Kittsendale

Event mean concentrations for total suspended solids

Event mean concentrations for total suspended solids.
Link to this table

Land cover/land use	Range (mg/L)	Recommended value (mg/L)	Notes
Commercial	42-164	75	If applicable to models being used, adjust curve numbers/runoff coefficients when calculating loads
Industrial	70-170	93	If applicable to models being used, adjust curve numbers/runoff coefficients when calculating loads
Residential	42-101	73
High-density/Multi-family residential		Calculate	Insufficient information to recommend a specific emc
Medium density residential		Calculate	Insufficient information to recommend a specific emc
Low density residential		Calculate	Insufficient information to recommend a specific emc
Freeways/transportation	50-90	87
Mixed	47-188	76 or calculate	Residential land use was the primary land use in most studies that cited values for mixed land use If the study area can be delineated into specific land uses and impervious area for each land use is know, we recommend calculating the emc
Parks and recreation		Use value for open space or calculate	emc will be a function of vegetative cover
Open space	11-70	21
Conventional roof		<20
Institutional	17-140	80
Forest/shrub/grassland	26-140	72	Sediment concentrations from forested areas vary widely with factors such as slope and forest condition. Concentrations may be very high, but the annual volume of runoff is typically much less than non-forested areas.
Open water and wetlands		see Notes (next column)	If data exist, use the TSS concentration for the water body of interest If data for a specific water body do not exist, use data from similar lakes in the area
Cropland (row crops)	50-160		Literature review was not adequate to recommend an emc
Pasture	75-150	84	Concentrations are a function of intensity of use.