Ontario Operator-in-Training (OIT) Practice Exam

What occurs when a sewer is surcharged?

1. the sewer is empty

2. the sewer overflows

3. hydraulically overloading a sewer

4. the sewer is repaired

The correct answer is: hydraulically overloading a sewer

When a sewer is surcharged, it indicates that there is an excessive amount of wastewater flowing through it, resulting in hydraulic overload. This occurs when the flow exceeds the capacity of the sewer system, which can happen due to heavy rainfall, snowmelt, or blockages within the system. During surcharging, the water level within the sewer rises above normal conditions, and while this condition can lead to overflowing or backups, the term "surcharged" specifically refers to the excessive pressure and volume of water within the sewer system. It is important to understand that although overrunning may occur as a result of this condition, the primary characteristic of a surcharge is the hydraulically overloaded state of the system. In contrast, an empty sewer would not be experiencing any surcharge, and repair activities would typically address issues causing the overload rather than describing the state of the sewer itself. This makes the understanding of surcharge crucial for effective management of wastewater systems.