Drain line cameras can catch it all on film.

One of the growing trends in our industry has been the use of drain line cameras. The original black and white systems have been advanced to new color videotapes. Some even have talkies. One of the newer cameras on the market has a GPS sensor in the camera head that allows the underground piping to be accurately mapped. I can just imagine how much that baby costs!

What many of you are unaware of is that these same, wonderful cameras are being used to spy on your work. That’s right — it’s just like Candid Camera. You finish a job, and somebody else shows up to critique your work.

The Plumbing Paparazzi

Remember that old adage, “Once it’s buried, nobody will know.” Surprise! They know now. By just running a camera down a drain, the video tells all you want to know. Any mistake shows up on wide-screen TV.

I’ve had to watch many drain line videos in the past two years. Everyone looks at you kind of strange when you pop the tape into the VCR and sit down to watch two hours of sewage running down a pipe. Of course, the exciting part of the “movie” is when I see the camera go under water and the pipe is full. The plot thickens as the water slows down to no movement. In the final scene, the camera exits the water and there is slow movement of sewage down the pipe. Ah-ha! You’ve just viewed a marvelous picture of a pipe with a sag in it. You found a failure!

Of course, if you are the guy that has to review the hours of sewage running down the pipe, you look forward to finding a screw up. It’s like going to a car race and cheering for the accidents.

On the other hand, if you are the contractor, the last thing you want to find is a screw up in the piping. That means problems. You are better off finding stoppages that can be cleared than screw ups in the piping installation.

I recently completed the review of a newly installed building that was a slab on grade. Alongside the slab construction were numerous tunnels that linked the adjacent buildings. The tunnels were 25 feet below grade. During construction, the slab on grade sections of the building were constructed on 18 to 20 feet of filled ground. The engineering specifications called for compaction of the soil to 95 percent.

The plumbing contractor either didn’t understand compaction requirements or simply trusted the general contractor. The underground drains were installed in trenches in a normal manner and backfilled. Most drains were 3 feet below the slab. After the plumbing contractor finished with the underground work, the slab on grade was poured. The two-story structure was completed, for the most part, without incident.

In a matter of nine months, the plumbing system started to foul up. A major line had to be repaired below the slab after it was realized that there was a break in the piping. That single repair started a snowball effect. How many other underground lines were in the same condition?

It’s elementary, Watson! When you are called in to investigate a failure (or potential failure), the first thing you try to do is use your experience to pinpoint where a problem might exist. For the first day of investigation, I identified five drains to scope with the drain line camera equipment. For the first drain we entered with the camera, everyone in the facility was gathered around to watch. Sure enough, there was a section of piping with standing water. Hence, we had documentation that there was a sag in the piping.

By the end of the day, we determined that all five drains that I identified as potential problems did, in fact, have problems. I was feeling really proud about the day’s investigation, so I called my wife to tell her how good I was at playing Sherlock Holmes. She congratulated me for being such a brilliant investigator.

But after three days of videotaping all of the underground drains, my ego was totally deflated. As is turns out, every drain we scoped with the camera had a failure of some sort. My random selection the first day was meaningless. I could have picked five other drains and gotten the same results. I wasn’t such a brilliant investigator after all.

The underground piping was either PVC plastic pipe or no-hub cast iron. The no-hub cast iron was broken in sections while the PVC sagged. Upon further investigation of the building, it was determined that the compaction was between 78 percent and 82 percent, at best. In one section of the building, there was an 18-inch void under the slab. Quite a bit of settlement for a two-story building.

Now the problem became a question of, “What do we do next?” Within the next two months, construction will begin on the renovation of the underground drainage system. The cost for repairing the system will exceed $1 million — a substantial sum when compared to the original contract price. In the meantime, the plumbing contractor was sold to a consolidator. The arguments between general contractor and plumbing contractor continue.

The problem for both contractors is the videotape. Any plumbing contractor with the camera equipment can start his own news magazine showing exclusive footage of another guy’s screw-ups.

One contractor I was speaking to about this project mentioned that he purchased a camera system to prevent it from being used against him. Rather than waiting for a candid camera situation, he will videotape systems to prove that they have a good installation. If he happens to find a problem, he fixes the installation before it is blown out of proportion. (However, he admits that he has not found any problems with his installations.)

So, the next time you are installing any piping that will be hidden, don’t think that it will be out of sight, out of mind. There may be somebody lurking in the bushes ready to jump out and yell, “Smile, you’re on Candid Camera.”