Expected performance benefits for various dewatering practices.
Link to this table
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Dewatering Best Management Practices |
| Sedimentation/ Settling Only (Sediment Traps/ Basins) |
Filtration Only (Silt Fence, Dewatering Bag, Geotextile, etc.) |
Pretreatment1 + Chemical Flocculants + Settling/Filtration |
| Water quantity |
|
| Flow attenuation |
Secondary benefit |
Little or no benefit |
Little or no benefit |
| Runoff volume reduction |
Secondary benefit |
Little or no benefit |
Little or no benefit |
| Water quality |
| Soil erosion |
Little or no benefit |
Little or no benefit |
Little or no benefit |
| Sediment control |
Good results |
Better results |
Best results |
| Nutrient loading2 |
Good results |
Better results |
Best results |
| Pollutant removal |
| Total suspended solids |
Good results |
Better results |
Best results |
| Total phosphorus2 |
Good results |
Better results |
Best results |
| Heavy metals |
Good results |
Better results |
Best results |
| Floatables |
Little or no benefit3 |
Good results |
Good results3 |
| Oil and grease |
Little or no benefit3 |
Some benefit |
Some benefit3 |
1 Pretreatment via settling and/or filtration.
2 For soil-borne nutrients; i.e., not dissolved forms.
3 Benefit can be significantly improved with the use of a floating skimmer for discharge
