How often should manholes be inspected in sewer mains that are not cleaned annually?

How often should manholes be inspected in sewer mains that are not cleaned annually?

• A. Every year
• B. Every 2 years
• C. Every 5 years
• D. Every 10 years

Answer: (B)

Maintenance timing for manholes is tied to how often the sewer mains are cleaned. When cleaning isn’t done annually, inspecting every two years is the practical balance that still catches developing problems—like sediment buildup, cracks, or misaligned frames—without overburdening resources. An annual inspection would be more than needed for this scenario, while much longer intervals (five or ten years) could allow issues to go unnoticed. Biennial inspections provide a reasonable, proactive check aligned with the reduced cleaning frequency.

Maintenance timing for manholes is tied to how often the sewer mains are cleaned. When cleaning isn’t done annually, inspecting every two years is the practical balance that still catches developing problems—like sediment buildup, cracks, or misaligned frames—without overburdening resources. An annual inspection would be more than needed for this scenario, while much longer intervals (five or ten years) could allow issues to go unnoticed. Biennial inspections provide a reasonable, proactive check aligned with the reduced cleaning frequency.