| Byproduct material | Particle-size fraction | Hydraulic conductivity | p-value* | ||
| Average | Variance | ||||
|
| mm | cm∙min−1 |
| ||
| Red mud iron filter cake | |||||
|
| <6 | 10.6 | 14.6 |
| 0.14 |
|
| <12.5 | 16.3 | 45.9 |
| 0.02 |
| Water treatment residual | |||||
|
| <6 | 8.0 | 4.1 |
| 0.44 |
|
| <12.5 | 43.1 | 684.8 |
| 0.05 |