17. A building sewer pipe and water service pipe are both constructed of PVC pipe and are installed in the same trench. The water service pipe shall be installed a MINIMUM of how high above the sewer pipe
Answer: C
The water service pipe shall be installed a minimum of 12 inches above the sewer pipe.
In installations where a building sewer pipe and a water service pipe are constructed of PVC and laid in the same trench, the water service pipe must be positioned at least 12 inches above the sewer pipe to ensure proper separation and prevent contamination.
A) 0 inches
Installing the water service pipe at 0 inches above the sewer pipe is incorrect as it offers no vertical separation. This lack of elevation could lead to potential contamination of the water supply from the sewer line, violating health and safety regulations.
B) 6 inches
While 6 inches provides some elevation, it is still insufficient to ensure the necessary separation between the water service and sewer pipes. This minimum height does not comply with safety standards aimed at preventing cross-contamination.
C) 12 inches
The requirement that the water service pipe be installed a minimum of 12 inches above the sewer pipe is correct. This elevation is crucial for maintaining safe distances between the two systems, thereby reducing the risk of contamination and ensuring compliance with plumbing codes.
D) 18 inches
Although 18 inches would provide even greater separation, it exceeds the minimum requirement specified for installation. While higher separation is generally better for safety, the question specifically asks for the minimum height, making this option unnecessarily excessive.
Conclusion
The correct answer is 12 inches, as it represents the minimum required height to maintain safe separation between the water service and sewer pipes. Options A and B fail to provide adequate elevation, while D, although safe, exceeds the minimum requirement. Thus, C is the only option that meets the necessary standards for safe installation.