Where must PCBs always be assumed present?

Where must PCBs always be assumed present?

• A. In household waste
• B. In air near old transformers
• C. All underground structures
• D. On the surface of water

Answer: (C)

PCBs were widely used in dielectric oils inside electrical equipment, especially in older transformers and capacitors. Because many underground structures (vaults, cables, underground transformers) were built with PCB-containing oil and PCBs persist in soil and equipment for long periods, you must treat these underground structures as potentially PCB-contaminated. This precaution helps prevent exposure during maintenance, digging, or disposal and ensures proper safety and environmental procedures are followed. The other options aren’t universally true: household waste isn’t routinely PCB-containing, air near old transformers isn’t guaranteed to carry PCB hazards in all cases, and contamination on the surface of water isn’t a reliable universal rule for underground structures.

PCBs were widely used in dielectric oils inside electrical equipment, especially in older transformers and capacitors. Because many underground structures (vaults, cables, underground transformers) were built with PCB-containing oil and PCBs persist in soil and equipment for long periods, you must treat these underground structures as potentially PCB-contaminated. This precaution helps prevent exposure during maintenance, digging, or disposal and ensures proper safety and environmental procedures are followed. The other options aren’t universally true: household waste isn’t routinely PCB-containing, air near old transformers isn’t guaranteed to carry PCB hazards in all cases, and contamination on the surface of water isn’t a reliable universal rule for underground structures.