Booby Traps

[digger242j]

I've been thinking about the story that Steve cited in his thread "Call Before You Dig". The link to the newspaper story is no longer working. I tried it this morning because I wanted to read it again to see if my recollection of what it said is clear. My recollection is that the contractor in question was digging up a concrete driveway, and that the gas line in question was embedded in the concrete. Certainly, we've all read enough stories in the news media to know that getting the details straight is not at the top of their list of priorities, so it's possible that what I think I remember from the story isn't what was really going on, but for the sake of arguement, let's assume that's what happened. I know from experience that it's certainly within the realm of possibility.

How many of us would even *remotely* expect to find a gas line embedded in a concrete driveway slab? If the contractor had called for a locate, he'd have had markings on the ground that indicated there was a gas line *somewhere* below. If I'd been in that position, the chances are very good that I'd have pulled the slab up first, and started looking for the line below it. Or worse yet, I'd have taken a compressor and a breaker and might very well have punched a hole right through the line, blowing myself up right then and there.

My point is this--while the contractor who failed to make the call for the locate is in violation for that "sin of omission", the guy who poured a concrete driveway slab around a live gas line is equally at fault, if not moreso. He left a booby trap that was waiting to catch somebody years later.

Every day many of us contend with working around facilities that have been installed by people we'll never even see. Sometimes they're easy to find and avoid--they have warning tape and a nice bed of sand or other select backfill around and above them. They're at the expected depth--not inches below the surface, or many feet lower than is the standard. Other times...well, they're just booby traps.

I've been caught a few times, luckily never with such disasterous results. Anybody else ever get caught?

[Dirtguru]

A close friend is a dry utility excavation contractor. Four years ago he was contracted to place fiber optic conduit in a country club filled with exclusive homes. Locates were called in and placed on time by a locating contractor, all utilities appeared to be under the asphalt. The C.C. had just repaved all of there streets so excavating in the street was out of the question. The decision was made to directional bore in the right of way's off the edge of pavement. Everything went along fine until one day the bore crew pulled back primary electric wire. Luckily no one was injured and not much property damage. Strange thing was why was the electric so far from the locate paint. Turns out that the power, phone and catv co's had jointly placed all new conduit to replace the old direct bury cables. Problem was power co never pulled any new wire thru the new conduits. Locator used most recent asbuilt map assuming it showed the correct locations based on the recent date of the map, other utilities had already placed cables in there conduits. Major communication breakdown between power co and locator, had the power co had there own locator familiar with the area or caught this when it came across the engineers desk before it went to locator this could have been avoided.

A Chapman

[DKinWA]

This is actually part of a bigger problem that I see occur regularly. I don't know how many times I've heard people whine or complain about having to do something to code because it costs more money. Codes may not always make sense, but there's usually a story behind why a particular code was enacted.

Never in my wildest dreams would I imagine that a gas line was encased within a concrete driveway slab. I'm reasonably sure this is a code violation and the contractor or homeowner did it this way to save time or money. It definitely saved some time and money, but look at the outcome. Like digger, I probably would've pulled up the concrete prior to having things located and I probably would've been in a world of hurt.

[RonG]

This is a couple of pics of a job I did 4 or 5 years ago.I had plenty of time to take pictures while waiting for the CBYD guy to come back out:))
It was a private "locator" company and their argument was that they are allowed to be 3 feet off with their markings before they could be held liable for damages.
It turns out that there were also utilities where the markings were too but they were still way off on the house electric service as I found out on up the trench there.
The cable tv guys are the ones I have a problem with the most,they are the "wh_res of the industry.They go into an old development and lay cable inches below the surface and don't use marking tape or any other clue that there might be something buried there.It does not bother me too much when I hit their stuff. Ron

Guess I need to work on the "posting pics" thing,huh?:))

[Steve Frazier]

Around here, the code is utilities must be buried a minimum of 18" or otherwise encased in concrete. I wonder if the driveway pour counted as the latter? It doesn't seem there would be any safe way to repave the drive without shutting the gas off first in this case, and "Who'da thunk it?" It will be interesting to see how this pans out, I'll try to keep track.

I run into shallow TV cable more times than not. I was digging along side a marked utility line with my hoe on one job, and my stabalizer severed the TV cable buried just a few inches below the surface. On another job for a sidewalk installation, I was excavating 8" for the base material and severed another line! Seems they would rather come out and make repairs instead of installing to code!:beatsme

[RonG]

That is the impression I get too Steve,it is easier to repair the breaks than to install it correctly and I would pretty much agree with them......It would take a long time to do it right and all their new installs are down there in the same trench with everybody elses so as time goes on a larger percentage of their service is safe and a smaller percentage of their workforce is required to maintain installs the pimps did so I think it was a calculated plan on their part and just to cost of doin business.I have noticed that I never had to wait too long for the repair guys.It seems that the guys who do the installs have the same markouts that we get and when they are crossing a potential hazard they get pretty shallow sometimes:))
Gas lines have to be down 30" and one would think that would be below any driveway base.My guess is that the driveway might have been installed after the house was built........meaning it was an afterthought or something.I have seen that happen and I would never have expected to find any utilities in the concrete slab.I probably would not have thought twice about a markout either.Does anybody know what I am doing wrong on this pic posting thing?What part of the instructions am I missing?

[RonG]

Well,now that I got one of the pics up.let me try the other one:))

[digger242j]

This one is such a shining example that I just can't help but share...

The task for the day was to expose the electric box, which had been placed 2 feet lower than finish grade by the electric company crew. The box was to be raised, and any dirt that was in the way of installing the electric service lines to the meter bases was to be removed.

The picture was taken while standing directly over the feed to the electric box. You can see one of the meter bases on the wall beyond the box. The other one is hidden, around the corner to the right.

The utilities, and the paving were installed months before excavation was begun for the building. The white arrow shows the original location of the gas service line, and curb stop. Where it had originally been placed, it would have been well inside the house. It was also substantially deeper than finish grade. When it was uncovered during the excavation for the building, it was left tailing up out of the ground, until someone was ready to deal with it further.

When the day came to deal with it further, the operator dug from where it was exposed, (heading to the right, remember), back across the mouth of the garage (to the left), ending at the meter location on the far left side of the garage, out of the picture. The yellow arrows show roughly where the gas service line is.

The job superintendent was all hot to get the gas hooked up. The plumber was equally in a hurry. (The plumber will normally have a hissy fit if the superintendent asks him to connect the downspout of one house into the rain leaders of another, citing the possibility that ten years from now there might be a clog, and they'll find out that he did something illegal, and everybody'll get sued, and he'll lose his license.) The plumber hooked up to it. The gas company inspector inspected it and hung the meter. The operator, recognizing the potential problem, was very diligent in putting lots of sand, and warning tape over the service line when he covered it. (Nobody bothered to supply the operator with "gas line warning" tape. The tape was yellow "caution" tape. It's the same stuff that's used to barricade holes we dig, and commonly, anybody but us rips it down and leave it in a pile on the ground, so it ends up just about anywhere. Also, that end of the alley was where the bricklayer had set up his mixer for that whole end of the building, so there was sand everywhere.)

Fast forward six weeks. I'm asked to handle raising the box. In an uncharicteristic show of foresight, the superintendent made the locate call.

All the electric and phone stuff was marked for the whole block. The gas company marked the main. Only.

I looked at the meter, the curb box, and the location of the main, and concluded that anything yellow was well off to my left. Since the electric stuff was deep, and only on the near side of the box, I felt safe in taking a couple of buckets out from the far side. Silly me.

I did give it a little pull, but I did feel it too. No damage, fortunately.

Anybody else think they'd have been as lucky?

.

[RonG]

This was your day and your skills gained from years of experience paid off.When you hook onto something with a bucket tooth and all your senses are in gear it is often a combination of imput that alerts you that "sumpin ain't right here".
When I was working for the company whose equipment is in the pics above there we used to do quite a bit of work for an electric contractor who managed to install a lot of big generators for backup power at older commercial buildings.Many of the installations had little to no records or asbuilts of the utilities in the ground and every one we did was exciting.
We always got markouts and of course they are a big help but there was often other things in the ground that nobody knew about (site lighting,alarm wiring,cable tv and of course sprinkler plumbing too)that were good for a few heart attacks each day.
Your situation was a combination of errors that began way before you arrived and it appears to me that somebody changed the elevation of the building for whatever reason without consulting with engineering.
As long as you got the markout and had the dig number you were covered but that is another great example of human error and reminding us all that it is alive and well among us.
More often than not I would have hit whatever it was and suffered the consequences,LOL.
It keeps me humble. :angel Ron G

[digger242j]

Your situation was a combination of errors that began way before you arrived and it appears to me that somebody changed the elevation of the building for whatever reason without consulting with engineering.

Actually the situation is that the roads and alleys have all been put in. The utilities, including servivce lines out to the curb stops have all been installed. The building in the picture is a 7-unit townhouse. The garage you see is that of the end unit; it's in line with the alley, and the rest are beside it, to the right. The site contractor had to build the elevation of the alleys up quite a bit. (If you look through the opening to the right of the meter base, you can see how much lower the street is. They simply didn't make the edges of the alley high enough for the electric box to be installed at the proper grade.)

As far as the gas service line goes, somebody did redesign the building. That's why the original location of the curb box was inside the building.

Here's a pic from another angle, looking across the alley. The gas meter is so high in the air, not because all that was excavated, but because that's how much the ground sloped away from the end of the alley to begin with. Counting courses of block, it looks like we'll be putting in about 40" of fill to make grade right there at the corner of the building.