- The water seal effectively prevents odours <br>- The excreta of one user are flushed away before the next user arrives <br>- Suitable for all types of users (sitters, squatters, wipers and washers) <br>- Low capital costs; operating costs depend on the price of water | con= - Requires a constant source of water (can be recycled water and/or collected rain water)<br> - Cannot be built and/or repaired locally with available materials The U-trap can easily become blocked<br> - Requires some education to be used correctly