Did I hit a gas line?

[JoeSomeone]

Hi folks, new here. I have a serious question I joined to ask you folks, because I wanted to ask some people with experience, as I have only been in the field for a year.

I am wondering whether we hit a gas line. We were drilling a monitoring well in New England. Once we finished the well, and the pvc was in, we heard a soft bubbling. The PID registered hits and then a few minutes later water started gushing out of the well a few feet high for half an hour, then it kind of slowed to a trickle if anything, before we filled it in. Now, it was either not DigSafed or the locator missed it. I did not see yellow paint (saying 'ok' or something to confirm there weren't lines) at the site. A geologist there said it was probably just a natural methane pocket, nothing to worry about. The spot is a parking lot in an urban area where buildings used to be in the 80s but it was made a parking lot in the 90s. We sampled the water and air above the well (in a bag sent to the lab) and they said there was a small amount of methane, 0.14%. Now that is pretty small, less than 10% of the lower explosive limit of 0.5%. There were hits for chlorinated solvents, which are present throughout the area, which is why the PID beeped. This was many months ago. I just can't sleep at night though knowing this. There aren't buildings too close, but they are close enough that I worry. So we just filled in the whole well, and I go back every now and then to look at it from the road and it seems fine. No hissing or bubbling.

Now, the National Grid emergency gas people came out to take a look and said it was not gas. But they said a locator would come and they never did. The gas company guy didn't seem to know what he was doing and I don't feel like I trust them. I am probably going to re-Digsafe it to see whether a locator actually comes out and writes No Gas or OK or something. But I just wanted to see what folks here thought? Also the Water dept. came out and it was not water, and the sewer people said that it couldn't be sewer. There was no smell of sewage. And definitely no smell of gas, several people there, no one smelled gas. The weird part is that the water came out of a well screened 25 to 30 feet below ground! I don't know why hitting a gas line 2 feet below ground would cause that, but I am just paranoid. I wanted to see if anyone thought it could be something else, and if so, what? Could it really be a 'methane pocket'? I tried to call National Grid to ask for a gas line map and they would not give me any info. They just said there used to be lines on the property. Maybe it is an old line they did not turn off or something? I just want to know so I can sleep at night. Wanted to make a new thread, but it said I was not allowed. Thanks all, sincerely, for any thoughts.

 

[JoeSomeone]

I should mention the depth to the water table was almost 9 feet below grade. So I don't see why gas would make water come up from the well. It was coming out of the well not the ground around it, if I recall right. That would mean gas would have to go down 30 feet, then push water up 30 feet. That doesn't make sense because pressure follows the easiest route. I'd assume it'd be able to just seep out around the pipe and go up 2 feet to the surface. Just thought I would throw this at a couple random people. I am going to try to talk to a few excavators I see out and about sometime too, although one guy I talked to made me nervous because he said sometimes natural gas loses the smell from the odorant. Wish I could just know everything is ok.

 

[digger242j]

You need three posts to be able to start a new thread. It helps to keep the drive-by spammers away.

I moved your posts to a thread of their own.

It's an interesting question. I'd have to guess that if you'd hit a gasline you'd know as soon as it happened. I've always know right away. (Uh, not that I ever hit one....)

That having been said, it would be real interseting to know what exactly caused the symptoms you described....


Oh, and welcome to Heavy Equipment Forums! :drinkup

 

[Squizzy246B]

The hydrocarbon test meter thingamajiggies are pretty good. If you had a leak from a gas pipe they would be able to tell fairly easily. The meter will squeal like a stick pig if there is even the slightest leak.. Uh....like Digger I only heard about this of course

 

[danhoe]

I bid on a job not to long ago in Southeastern Michigan reading the soil borings provided with the bid package. One area of the job had pockets of methane gas, the drillers found it. Go get some sleep if there was a problem it would have surfaced along time ago. The odor that is put in natural gas does not lose its smell, when I was doing horiz. bores we would buy used steel pipe and some of the pipe stunk really bad. The National gas grid will not be shared due to 911. digger

 

[#12Caterpillar]

Here in Wyoming we have natural gas lines going in every direction you can shake a stick at, and my experiance in the gas patch (about ten years now):Banghead if you would have hit a gas line you would not be here to be asking about it just for an exampel back in the mid 90,s they where putting in a new line just down the road from where I work now and a D8 operator sank his riper tooth in the ground and hit a pipe and well if they had not known the person in the D8 they said even the dentel records my not have even helped. A more recent one was over by Cheyenne Wyoming just a few years back I think it was just about the same deal. A lot of our gas lines over here are full of unprosesed gas witch has no oderent in it so you have a hard time even smelling the stuff. They save the stinky stuff for the gas headed out to your homes. So to answer your question the only thing that I can think of is where the water table was only 9 feet below the grade is maybe an artisen well with a little bit of methain gas in it. :usa

just my $0.02 worth

 

[CinOK]

Since this area has been "reclaimed" a few times there is a possibility that you may have hit something that shouldn't of been in the "clean" that was used at a previous time. I did hit a plumbers tank on time while i was augering deck piers on new construction the filled the area and apparently the dozer operator borrowed a misplaced acy tank. Luckily their was no flash and boom, real good muck as back fill thankfully, but it did blow out the hole.

 

[tonka]

I hit a gas line with a backhoe once, that thing spewed like a stuck pig for a long time untill we shut the main down. I think if you hit a gas line she would still be spewing and you would know you hit a gas line cause you H2S monitor would be chirping like a birdie!
Like CinOK said the PVC you hit could be some garbage in the fill area that didnt get cleaned up very well, or a leach line or something.

 

[Arabhacks]

Gas!?

Hello and welcome.

Yes, if you hit a gas line you would know it.
http://www.gasodorant.com/order.php
I have only bruised a gas line once and was able to feel it in my backhoe.
Water linesv are another matter altogether. :Banghead
Listen to what the more learned on this board have to say, I have read hundreds of posts and so far everyone is on the money, or somebody calls them on it.
This part of industry is one place where you can not fake it, 5 minutes on a machine will tell the tale. :notworthy

Thank you.

 

[Aliate]

Here in Wyoming we have natural gas lines going in every direction you can shake a stick at, and my experiance in the gas patch (about ten years now):Banghead if you would have hit a gas line you would not be here to be asking about it just for an exampel back in the mid 90,s they where putting in a new line just down the road from where I work now and a D8 operator sank his riper tooth in the ground and hit a pipe and well if they had not known the person in the D8 they said even the dentel records my not have even helped. A more recent one was over by Cheyenne Wyoming just a few years back I think it was just about the same deal. A lot of our gas lines over here are full of unprosesed gas witch has no oderent in it so you have a hard time even smelling the stuff. They save the stinky stuff for the gas headed out to your homes. So to answer your question the only thing that I can think of is where the water table was only 9 feet below the grade is maybe an artisen well with a little bit of methain gas in it. :usa

just my $0.02 worth

Those are gas transmission lines. They are much much much bigger than 90% of the gas lines in the ground. Around here where I live there are a few and Ive crossed one once, it was 32" in diameter, Tennessee Gas sent an inspector out to watch us dig, and they fly up and down the lines with helicopters to make sure nobody is digging without them knowing. Google gas transmission line hit and you will see pictures of craters the size of houses. Gas lines that go to the house can just be folded over and tapped if you cut one, they are very low pressure, of course you shouldnt leave it like that.