Contractors are often called upon to locate leaks and sources of inflow in sanitary sewers, or to identify faults in mains, laterals, and house plumbing, including roof and yard drains. They may be asked to find sources of odors, locate cross-connections, trace plumbing and power plant piping, and analyze onsite treatment systems.Smoke and dye testing are simple, inexpensive, yet effective methods for conducting those kinds of investigations. Smoke-generating devices (SGD) using candles, bombs, and liquid agents help pinpoint leaks in sewer pipes. Fluorescent dyes make it easy to trace errant flows of water to the source. By knowing what to
