BMP pollutant removal for phosphorus

This table shows comparison of phosphorus removal for different BMPs.^a,e,f Values represent the percent of incoming pollutant that is removed. Source: MPCA Minnesota Stormwater Manual.
Link to this table

Information: Removal rates shown here are composite averages intended solely for use in comparing performance between BMP designs and for use in calculating load reduction in site-based TP models. They have been adapted, rounded and slightly discounted from statistical values published in BMP performance databases.

BMP group	BMP design variation	Average TP removal rate (%)b	Maximum TP removal rate (%)c	Average soluble P removal rate (%)d,f,g
Bioretentionf	Underdrain	50	65	0
	Infiltration	100	100	100
Filtration	Sand filter	50	55	0
	Dry swale	0	55	0
	Wet swale	65	75	70
Infiltrationf	Infiltration trench	100	100	100
	Infiltration basin	100	100	100
Stormwater ponds	Wet pond	50	65	0
	Multiple pond	60	75	0
Stormwater wetlands	Shallow wetland	40	55	0
	Pond/wetland	55	75	0

^aRemoval rates show in table are a composite of five sources:

• Caraco (Center for Watershed protection, 2001)
• Maryland Department of the Environment](2000)
• Winer (Center for Watershed Protection, 2000)
• P8 modeling (William Walker)

^b Average removal efficiency expected under MPCA Sizing Rules 1 and 3
^c Upper limit on phosphorus removal with increased sizing and design features, based on national review
^d Average rate of soluble phosphorus removal in the literature
^e See section on calculating credits for each BMP in this Manual.
^f Note that the performance numbers apply only to that portion of total flow actually being treated; it does not include any runoff that bypasses the BMP
^gNote that soluble P can transfer from surface water to groundwater, but this column refers only to surface water
^hNote that 100% is assumed for all infiltration, but only for that portion of the flow fully treated in the infiltration facility; by-passed runoff or runoff diverted via underdrain does not receive this level of treatment.