Which of the following would be the best use of closed-circuit TV by wastewater collection system workers?

• A. Chemical addition
• B. All of the above
• C. Removing sources of infiltration
• D. Evaluating the effectiveness of sewer cleaning & clearing techniques

Answer: (D)

Closed-circuit TV is used to visually inspect the inside of sewer lines. The best use here is to evaluate how well sewer cleaning and clearing techniques worked. After cleaning or clearing, the camera lets workers see whether debris has been removed, whether any remaining obstructions or pipe defects exist, and whether the line is truly passable. This direct view helps decide if another cleaning pass is needed or if repairs are required, making it the most informative use of CCTV in this scenario. While CCTV can help locate sources of infiltration, its primary value in this context is confirming the effectiveness of cleaning and clearing efforts.