m |
m |
||
Line 59: | Line 59: | ||
</tr> | </tr> | ||
<tr> | <tr> | ||
− | <td>[[Filtration|Dry swale]]</td> | + | <td>[[Filtration|Dry swale]] (no check dams)</td> |
<td>68</td> | <td>68</td> | ||
<td>[http://stormwater.pca.state.mn.us/index.php/Phosphorus_credits_for_bioretention_systems_with_an_underdrain link to table]</td> | <td>[http://stormwater.pca.state.mn.us/index.php/Phosphorus_credits_for_bioretention_systems_with_an_underdrain link to table]</td> | ||
Line 70: | Line 70: | ||
</tr> | </tr> | ||
<tr> | <tr> | ||
− | <td>[[Wet swale (wetland channel)|Wet swale]]</td> | + | <td>[[Wet swale (wetland channel)|Wet swale]] (no check dams)</td> |
<td>35</td> | <td>35</td> | ||
<td>0</td> | <td>0</td> | ||
Line 103: | Line 103: | ||
</tr> | </tr> | ||
<tr> | <tr> | ||
− | <td>[[Permeable pavement]]</td> | + | <td>[[Permeable pavement]] (with underdrain)</td> |
<td>74</td> | <td>74</td> | ||
<td>41</td> | <td>41</td> |
Median pollutant removal percentages for several stormwater BMPs. Sources. More detailed information and ranges of values can be found in other locations in this manual, as indicated in the table. NSD - not sufficient data.
Link to this table
Practice | TSS | TP | PP | DP | TN | Metals1 | Bacteria | Hydrocarbons |
---|---|---|---|---|---|---|---|---|
Infiltration2 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
Biofiltration and Tree trench/tree box with underdrain | 80 | link to table | link to table | link to table | 50 | 35 | 95 | 80 |
Sand filter | 85 | 50 | 85 | 0 | 35 | 50 | 80 | 80 |
Iron enhanced sand filter | 85 | 74 | 85 | 606 | 35 | 50 | 80 | 80 |
Dry swale (no check dams) | 68 | link to table | link to table | link to table | 35 | 80 | 0 | 80 |
Wet swale (no check dams) | 35 | 0 | 0 | 0 | NSD | NSD | 0 | NSD |
Constructed wet ponds4, 5 | 84 | 46 | 84 | 0 | 30 | 70 | 60 | 80 |
Constructed wetlands | 73 | 38 | 69 | 0 | 30 | 70 | 60 | 80 |
Permeable pavement (with underdrain) | 74 | 41 | 74 | 0 | NSD | NSD | NSD | NSD |
Green roofs | 85 | 0 | 0 | 0 | NSD | NSD | NSD | NSD |
TSS=Total suspended solids, TP=Total phosphorus, PP=Particulate phosphorus, DP=Dissolved phosphorus, TN=Total nitrogen
1Data for metals is based on the average of data for zinc and copper
2BMPs designed to infiltrate stormwater runoff, such as infiltration basin/trench, bioinfiltration, permeable pavement with no underdrain, tree trenches with no underdrain, and BMPs with raised underdrains.
3Pollutant removal is 100 percent for the volume infiltrated, 0 for water bypassing the BMP. For filtered water, see values for other BMPs in the table.
4Dry ponds do not receive credit for volume or pollutant removal
5Removal is for Design Level 2
6Removal is for Tier 2 iron enhanced sand filter. Tier 1 removal is 40 percent, resulting in a TP removal of 65%