General summary of comparative BMP phosphorus removal performancea,e,f
Link to this table

BMP Group BMP Design Variation Average TP Removal Rate (%)b Maximum TP Removal Rate (%)c Average Soluble P Removal Rate (%)dg
Bioretention Underdrain see Phosphorus credits for bioretention systems with an underdrain see Phosphorus credits for bioretention systems with an underdrain see Phosphorus credits for bioretention systems with an underdrain
Infiltration
  • 100 for infiltrated portion
  • 0 for non-infiltrated portion
  • 100 for infiltrated portion
  • 0 for non-infiltrated portion
  • 100 for infiltrated portion
  • 0 for non-infiltrated portion
Filtration Media Filter 50 55 0
Vegetative Filters (dry) 0 55 0
Wet Swale 0 40 0
Infiltrationf,i Infiltration Trench
  • 100 for infiltrated portion
  • 0 for non-infiltrated portion
  • 100 for infiltrated portion
  • 0 for non-infiltrated portion
  • 100 for infiltrated portion
  • 0 for non-infiltrated portion
Infiltration Basin
  • 100 for infiltrated portion
  • 0 for non-infiltrated portion
  • 100 for infiltrated portion
  • 0 for non-infiltrated portion
  • 100 for infiltrated portion
  • 0 for non-infiltrated portion
Stormwater Ponds Wet Pond 50 75 0
Multiple Pond 60 75 0
Stormwater Wetlands Shallow Wetland 40 55 0
Pond/Wetland 55 75 0

a Removal rates shown in table are a composite of five sources: ASCE/EPA International BMP Database;Caraco (CWP), 2001; MDE, 2000; Winer (CWP), 2000; and Issue Paper D P8 modeling
b Average removal efficiency expected under MPCA Construction General Permit sizing requirements
c Upper limit on phosphorus removal with increased sizing and design features, based on national review
d Average rate of soluble phosphorus removal in literature
e See also Calculating stormwater volume and pollutant reductions and credits
f Note that the performance numbers apply only to that portion of total flow actually being treated; it does not include any runoff that by-passes the BMP
g Note that soluble P can transfer from surface water to ground water, but this column refers only to surface water
h Note that 100% is assumed for all infiltration, but only for that portion of the flow fully treated in theinfiltration facility; by-passed runoff or runoff diverted via underdrain does not receive this level of treatment

Caution: 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.