Unexpected large scale infiltration of stream water
Unexpected increase in the population
Under estimates of maximum and average flows
All of the above
Answer is Right!
Answer is Wrong!
The correct answer is D. All of the above.
Sewer pipes are designed for maximum discharge with 25% to 33% vacant cross-sectional area to allow for unexpected large scale infiltration of stream water, unexpected increase in the population, and under estimates of maximum and average flows.
- Unexpected large scale infiltration of stream water can occur during heavy rains or flooding. When this happens, the water can flow into the sewer system and overwhelm the capacity of the pipes. If the pipes are not designed with enough vacant cross-sectional area, the water can back up and cause flooding in homes and businesses.
- Unexpected increase in the population can also lead to problems with sewer systems. As the population grows, more people are using the sewer system. This can increase the amount of wastewater that needs to be treated and can also lead to overloading of the system. If the pipes are not designed with enough vacant cross-sectional area, the wastewater can back up and cause flooding.
- Under estimates of maximum and average flows can also lead to problems with sewer systems. When engineers design sewer systems, they estimate the maximum and average flows that the system will need to handle. However, these estimates can be inaccurate, and the actual flows can be higher than expected. If the pipes are not designed with enough vacant cross-sectional area, the higher flows can cause the system to overload and back up.
To prevent these problems, sewer pipes are designed with 25% to 33% vacant cross-sectional area. This vacant space allows for unexpected events, such as heavy rains, flooding, or population growth, without causing the system to overload.