Which soil condition is NOT recommended for laying water supply lines?

Which soil condition is NOT recommended for laying water supply lines?

• A. In soft, clean soil and sand
• B. In rocky soil
• C. In hard, dry clay
• D. On paved surfaces

Answer: (D)

Installing water supply lines needs a trench that provides stable bedding and can be properly backfilled and protected. Soft, clean soil and sand let you trench and backfill smoothly with good support. Rocky soil makes trenching harder and can damage the pipe if not handled carefully, but it can still be worked around with proper technique. Hard, dry clay can expand or shrink with moisture changes, potentially causing movement unless carefully bedded and compacted. Laying lines on paved surfaces, however, requires cutting through pavement, disturbing the surface, and it does not provide the same reliable bedding and backfill environment; it also increases cost and repair work. Therefore, this option is not recommended.

Installing water supply lines needs a trench that provides stable bedding and can be properly backfilled and protected. Soft, clean soil and sand let you trench and backfill smoothly with good support. Rocky soil makes trenching harder and can damage the pipe if not handled carefully, but it can still be worked around with proper technique. Hard, dry clay can expand or shrink with moisture changes, potentially causing movement unless carefully bedded and compacted. Laying lines on paved surfaces, however, requires cutting through pavement, disturbing the surface, and it does not provide the same reliable bedding and backfill environment; it also increases cost and repair work. Therefore, this option is not recommended.