The small sewers are cleaned by

ANS:A - flushing

Small sewers are typically cleaned using a method called "cane rodding." Here's an explanation of cane rodding:

1. Cane Rodding: Cane rodding involves the use of long, flexible rods made from materials such as bamboo or fiberglass. These rods are inserted into the sewer manually through access points such as manholes or cleanouts.
2. Process: To clean the sewer, the rodding equipment is inserted into the sewer line, and the rods are pushed or rotated manually to dislodge obstructions and debris. The flexible nature of the rods allows them to navigate through bends and curves in the sewer pipe.
3. Clearing Obstructions: Cane rodding is effective for clearing minor blockages, such as accumulations of grease, hair, or other debris, as well as for dislodging tree roots that may have infiltrated the sewer line.
4. Limitations: While cane rodding is suitable for small sewers and minor blockages, it may not be effective for larger obstructions or more extensive cleaning needs. In such cases, alternative methods such as high-pressure water jetting or mechanical cleaning equipment may be necessary.
5. Safety Considerations: Cane rodding requires manual effort and can be physically demanding, especially when accessing and maneuvering within confined spaces such as sewer lines. Proper safety precautions, including personal protective equipment (PPE) and adherence to safety protocols, are essential to minimize risks to workers.

In summary, cane rodding is a common method used to clean small sewers by manually inserting flexible rods into the sewer line to dislodge obstructions and debris. It is a cost-effective and relatively simple technique for maintaining the functionality of small sewer systems.