Which of the following are construction defects that can cause problems in wastewater collection systems?

• A. All of the above
• B. Improper grade of sewers
• C. Improper taps
• D. Structure failure of manholes

Answer: (A)

Construction problems in wastewater collection systems often come from how the system is built. Each of these issues represents a defect in construction that can cause functional problems. If sewers aren’t graded properly, the slope may not support reliable gravity flow, leading to solids settling, blockages, or poor draining. When taps are done poorly, connections can be misaligned or leak, creating paths for infiltration or exfiltration and increasing the risk of blockages or sewer backups. Manholes that are inadequately constructed or fail can allow groundwater to enter or sewage to escape, compromising capacity and causing settlement or collapse.

Because any one of these flaws can lead to operational problems, all of these are construction defects that can cause issues in a wastewater collection system.