Tuolumne Utilities District (TUD) sewer collection field crews will be cleaning and smoke testing its sewer collection system tomorrow, Thursday, May 31, 2018 in Columbia. Residents in the vicinity of Parrotts Ferry Road in Columbia, near the Pedro Y, may notice smoke in the area just west of Parrotts Ferry Road between the hours of 8am to 3pm on Thursday, May 31, 2018. The smoke testing being conducted by TUD is an effort to limit the cost of treating rainwater at our sewage treatment plant and pumping costs at our lift stations.
Smoke testing is the process of injecting artificially produced smoke into a blocked off pipeline segment to see where the smoke emerges. If the sewer main is in good condition then the forced smoke will emerge from manhole lids along the line. If the line has defects, the smoke will find the break and try to escape through the break. It is not unusual to see plumes of smoke issuing up from peculiar places, such as cracks in the street, or in residential yards during smoke testing.