| 37000 | Cesspools emptying and cleaning |
| 37000 | Chemical toilets servicing |
| 37000 | Drains maintenance |
| 37000 | Human waste water collection and transport by sewers, collectors, tanks and other means of transport |
| 37000 | Local authority drainage services |
| 37000 | Local authority sewage services |
| 37000 | Rain water collection and transportation by sewers, collectors, tanks and other means of transport |
| 37000 | Septic tanks emptying and cleaning |
| 37000 | Sewage farm |
| 37000 | Sewage works |
| 37000 | Sewerage system maintenance and operation |
| 37000 | Treatment of human waste water by means of physical, chemical and biological processes |
| 37000 | Treatment of waste water (human, industrial, from swimming pools etc.) by various processes. |
| 37000 | |