Cincinnati sanitary drain leak detection using helium tracer gas

I was called out to a Cincinnati hotel job that was still under construction to perform a sanitary drain leak detection using helium tracer gas. The plumber had a sanitary drain that wouldn’t pass the final pressure test. Unfortunately, the concrete had already been poured, so I needed to hunt down the leak with helium tracer gas. They had already attempted to find the leak with drain a drain camera, but it was a small leak and not able to be seen by the camera.
The helium tracer gas process involves drilling through the concrete, following the path of the main drain and branches, roughly every 2-3 ft. We drilled roughly 60 holes throughout and ran the helium at a very low pressure so we wouldn’t blow out the “balloons” that hold the pressure in different parts of the system, as well as blow out the helium, which quickly expands and can give false readings. We only needed to test half of the system as the other half was holding. I used an electronic helium detector to hunt down the leak and was able to nail it down to a “Y” fitting in the main drain. The plumber, Bill Maag with WB Services, was very happy with the results and was kind enough to make a picture (See video on fb) and email it to me for this blog. -See attached.