| Blockage type | Company A | Company Ba | ||
| Total blockages | Percentage | Total blockages | Percentage | |
| Damaged pipe | 227 | 3.1 | 38 | 0.6 |
| Foreign object | no data | no data | 265 | 3.9 |
| FOG | 1552 | 20.8 | 517 | 7.5 |
| Sediment | no data | no data | 248 | 3.6 |
| Tree rootsb | 5001 | 67.2 | 4981 | 72.4 |
| Unknown/other | 664 | 8.9 | 830 | 12.1 |