Massachusetts Plumbers Journeyman Practice Exam

How should conductors and storm drains serving low roofs be configured when connected to a combined sewer?

1. A. Open to air

2. B. Direct connection

3. C. Trapped

4. D. Insulated

The correct answer is: C. Trapped

The correct approach for configuring conductors and storm drains serving low roofs connected to a combined sewer is to utilize a trapped system. This configuration is essential because traps help to prevent sewer gases from entering buildings and protect the drainage system from potential backflow. A trapped system also accommodates the flow of stormwater without allowing mixed sewage to back up into the system. The use of traps is particularly important in low roof scenarios where water accumulation can be more prevalent, as it ensures that any backpressure from the sewer system does not compromise the drainage and indoor air quality. Properly designed traps will help maintain the function of the drainage system while providing the necessary barriers against undesirable odors and gases. In contrast, other configurations like an open system or direct connection would lead to potential issues, such as exposure to air and gas infiltration, while insulation is not necessary in this specific application.