Although sewer cameras and similar equipment can be used to inspect a sewer or drain line, they are more limited in what they can see than many people realize. Yes, a good camera can be useful in spotting blockages and other immediate issues within a sewer line, there is a more efficient monitoring method that has been in use for decades. That is the sewer smoke test, and it can be used to locate blockages, leaks, and even anomalies that have been previously unknown.
A smoke test is incredibly simple and probably exactly what you might expect. A large amount of smoke and air is blown into a sanitation sewer line, usually through a manhole, and it is allowed to blow through the sewer line. The smoke always takes the path of least resistance, which means it will billow out of any opening it can find.
When it is used properly, a smoke test can uncover leaks in a sewer line as well as pathways, drains in homes, sump pumps, and anything else that could lead to a loss of water or water pressure in a sewer or pipe.
Even though smoke tests have been used to test and inspect sewer lines for decades, some people have raised concerns about safety. While the smoke that is commonly used in tests is generally safe, it is still important to inform residents of a neighborhood before a smoke test is performed. Some people claim that workers should wear respirators when they perform a smoke test, but this often isn’t necessary. In most cases, a smoke test is a perfectly safe way to learn more about a sewer line, one that has been proven to be effective for decades. The technique is still in use today, and will most likely be for years to come.