________ or __________ shall not be used below ground for water lines

________ or __________ shall not be used below ground for water lines

• A. PEX, CPVC
• B. Copper, Brass
• C. ABS, PVC
• D. PVC, Polyethylene

Answer: (D)

Underground water piping must be made from materials rated for direct burial and long-term potable-water use. In this context, PVC and polyethylene are not used below ground for water lines because they can be more vulnerable to underground conditions over time. Joints and connections on these plastics can be less secure under soil movement, temperature changes, or soil chemical exposure, increasing the risk of leaks or failure in buried applications. The typical approach is to use materials proven for underground service—such as copper, CPVC, or PEX—following the local code and manufacturer recommendations.

Underground water piping must be made from materials rated for direct burial and long-term potable-water use. In this context, PVC and polyethylene are not used below ground for water lines because they can be more vulnerable to underground conditions over time. Joints and connections on these plastics can be less secure under soil movement, temperature changes, or soil chemical exposure, increasing the risk of leaks or failure in buried applications. The typical approach is to use materials proven for underground service—such as copper, CPVC, or PEX—following the local code and manufacturer recommendations.