What Caused This??????????

[orezok]

I had a similar thing happen a couple of years ago. We were modernizing one of our schools. The gas was shut off during the mod. At the end of the project the landscaper came in and installed new irrigation.

About 2 years later, my electrician was trenching through the kindergarten yard and they began to smell gas. They stopped and called the gas company who came out with their sniffer to locate the leak. At a location about 4' from his trench they got a hit. They excavated and found an irrigation main line. Below the irrigation line was the gas line.

It appears that while the landscaper was trenching he nicked the top of the gas line, but since the system was off he did not know. The fluff probably covered the line and they didn't see it. Landscaper installed his line, backfilled and compacted the trench.

For 2 years no leak was detected until the electrician disturbed enough soil near the previous damage to cause it to leak.

What's more interesting is that we use medium pressure (5 PSI) to all our buildings.

Go figure! :confused2:

 

[SixHoeBob]

I would guess that somebody ran over the exposed pipe with a skid-steer loader when they were spreading the stones.

 

[lectro88]

I would guess that somebody ran over the exposed pipe with a skid-steer loader when they were spreading the stones.

I think your getting closer to what happened.
I've been in the building industry for 23yrs.

What I "think" happened, and none of us are 100% sure, right.

Sometime they use what is called a georgia buggy to haul concrete, for those that don't know what that is. It holds about as much as 3-4 wheel barrels on a tricycle type setup with about 10-12 hp engine powering it and you stand up on it and drive it like a bicycle. I don't think the pipe was exposed or broken when installed. I really think the pipe was just at the surface and georgia buggy or even more likely cause its heavier a skid steer with a bucket full of concrete crushed the pipe in the buzz of pouring, site noise and hurrying, it went un-noticed.

Just my opinion.

 

[Qapla]

It is always possible that the pipe was not "broken" when installed, but could have had a "slap-crack" in it. This can happen when PVC is dropped on the ground and a 20' piece of 4" is not light.

Also, that is DWV. DWV, even though it is schedule 40, does not have to meet the same specs as schedule 40 PVC water pipe. DWV is not intended to hold pressure and is manufactured as such. That is why it is usually a bit cheaper then PVC.

If it had a "slap-crack" or a ding or dent, it could have held drain water just fine. Then, when someone was running a power snake though there, the head broke through the pipe at the weak spot.

If the pipe was "old" at the time it was installed, it would have been that much more brittle. DWV is not UV protected and sunlight will dry out the plastic to a very brittle point.