Which test uses specially manufactured dyes to positively identify connections to sewage systems?

• A. Lamping
• B. Dye Test
• C. Smoke Testing
• D. Television inspection

Answer: (B)

Dye tracing is used to visually follow where wastewater goes, so you can positively identify which lines drain into which sewer segments. By introducing a specially manufactured dye into a fixture or cleanout, you watch where the colored water appears downstream—such as another manhole, a storm sewer, or a receiving drain. If the dye shows up in the target area, you’ve proven a connection exists between the tested line and that sewer, which is exactly what you need to confirm cross-connections or proper routing. The dyes are chosen for visibility (often fluoresce under UV light) and safety, making the flow path easy to observe.

This differs from other tests: lamping uses a light to locate lines but doesn’t trace flow; smoke testing pushes smoke to reveal leaks or venting issues rather than tracing wastewater paths; television inspection uses a camera to view the pipe interior without tracing dye through the system.