Table 6.
Direction for future research on design and operation of CWs.
| Parameter | Design Criteria | |
|---|---|---|
| FWS CWs | SSF CWs | |
| Bed size (m2) | Larger if available | <2500 |
| Length to width ratio | 3:1–5:1 | <3:1 |
| Water depth (m) | 0.3–0.5 | 0.4–1.6 |
| Hydraulic slope (%) | <0.5 | 0.5–1 |
| Hydraulic loading rate (m/day) | <0.1 | <0.5 |
| Hydraulic retention time (day) | 5–30 | 2–5 |
| Media | Natural media and industrial by-product preferred, porosity 0.3–0.5, particle size <20 mm (50–200 mm for the inflow and outflow) | |
| Vegetation | Native species preferred, plant density 80% coverage | |