During testing and inspection of newly laid sewer pipes, which of the following tests are standard practices to verify soundness and alignment?

Introduction / Context:
Commissioning of sewer lines includes field tests to detect leakage, sags, misalignment, and blockages before acceptance. Using multiple simple tests provides assurance that the pipeline will perform as designed.

Given Data / Assumptions:

• Gravity sewer pipe sections installed with manholes.
• Contract specifications require integrity, grade, and alignment verification.

Concept / Approach:

The water test fills a pipe section to a specified head to check for leakage. The ball test passes a ball (or mandrel) of standard diameter to confirm no obstructions and adequate bend clearances. The mirror test (or light test) confirms straightness by sighting a reflected light along the pipe barrel—any sags or offsets appear as discontinuities.

Step-by-Step Solution:

Verification / Alternative check:

Standard codes and municipal specs list these tests, sometimes alongside air tests and CCTV inspections for modern QA/QC.

Why Other Options Are Wrong:

(a), (b), or (c) alone do not cover all acceptance criteria. (e) is false since these are indeed standard tests.

Common Pitfalls:

Relying on a single test and missing defects; conducting tests before sufficient curing or backfilling; ignoring manhole-to-manhole alignment.

Final Answer:

All of these