Vegetated Swales
Vegetated Swales:
As the name implies, this is a planted technology, which serves to both infiltrate water and scrub pollutants. This is practically a free-form design, not unlike a rain garden, which can be fit onto most any landscape or scaled to manage a variety of runoff conditions. Vegetated swales can be designed with minimal impact, and typically do not require extensive excavation. The principal issues involve failure or reduction in performance due to clogging with sediment, and maintenance of biomass growth.
Typical Performance*
| Pollutant | Approximate % Removal |
| TSS | 81 |
| BOD | 67 |
| Nitrate | 38 |
| TP | 9 |
| Hydrocarbons | 62 |
| Cadmium | 42 |
| Copper | 51 |
| Lead | 67 |
| Zinc | 71 |
As per the EPA, see document 832-F-99-006, (1999)
This picture courtesy of the Massachusetts Office of Environmental Affairs,