1. Treatment of Urban Water Runoff Biofiltration using a Bioswale Robert Ryan UC Santa Barbara 11/30/04

2. Bioswales  What is a Bioswale and why use one?  How a Bioswale Works  Results of Bioswale usage  Benefits of Bioswale use and the Alternatives

3. What is a Bioswale? Figure 1.1 [bren study]

4. Why Use a Bioswale? Ecologically sound treatment of runoff. Includes:  Hydrocarbons  Heavy Metals  Sediment  Nutrients  And many more possibilities Would otherwise pollute downstream water ecosystems Figure 1.2 [bren study]

5. How a Bioswale Operates  Channels runoff from assigned watershed  Dimensions critical to efficient operation  Heavy volume flow is diverted Figure 1.3 [bren study]

6.  Water enters forebay of Bioswale  Water enters backbay  Sediments settle  Phytoremediation occurs  Output exits outlet pipe into natural or constructed waterway Figure 1.4 [bren study] How a Bioswale Operates, continued

7. Phytoremediation  Breakdown in soil, or accumulation in shoots and leaves  Certain plants for certain contaminants  Broad application (TNT) Figure 1.5 [soil.edu] Using plants to remove, transfer, or stabilize, contaminants in soil, sediment, and groundwater.

8. Results of Bioswale Use  Dramatic reduction of sediments Lower flow velocities Lower flow velocities  Reduction of hydrocarbons, nutrients, and metals EPA studies of Superfund sites: 30-70% decreases EPA studies of Superfund sites: 30-70% decreases  Mature plants more efficient at removal  Efficiency increases with size of Bioswale  High volume flow decreases efficiency

9. Additional Benefits and Alternatives  Benefits: Ecological Preservation Ecological Preservation Flood control Flood control Aesthetic Value Aesthetic Value Inexpensive in comparison Inexpensive in comparison  Alternatives Stormceptor (Costly) Stormceptor (Costly) FossilFilter (high maintenance) FossilFilter (high maintenance)

10. Conclusion  Bioswales meet increasing demand for mitigation measures to stop pollution from urban environments  Bioswales work Sedimentation Sedimentation Phytoremediation Phytoremediation