Comparative BMP phosphorus removal
General summary of comparative BMP phosphorus removal performancea,e,f (Click here to link to table)
| BMP Group | BMP Design Variation | Average TP Removal Rateb | Maximum TP Removal Ratec | Average Soluble P Removal Ratedg |
|---|---|---|---|---|
| Bioretention | Underdrain | 50% | 65% | 60% |
| Infiltration | 100 | 100 | 100 | |
| Filtration | Media Filter | 50 | 55 | 0 |
| Vegetative Filters (dry) | 0 | 55 | 0 | |
| Wet Swale | 0 | 40 | 0 | |
| Infiltrationf,i | Infiltration Trench | 100 | 100 | 100 |
| Infiltration Basin | 100 | 100 | 100 | |
| Stormwater Ponds | Wet Pond | 50 | 75 | 70 |
| Multiple Pond | 60 | 75 | 75 | |
| Stormwater Wetlands | Shallow Wetland | 40 | 55 | 50 |
| Pond/Wetland | 55 | 75 | 65 |
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 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 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