Water Main Leak Detection

dayexco

what methods have any of you used to detect a small water main leak that will not expose itself?

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someday, i'll be as patient as Nick.

Double-A

If you are chasing this with listening equipment, you might try nitrogen gas introduced into the line to get the leak to bubble, gurgle and hiss a bit. This can sometimes help hearing what otherwise can't be heard.

I assume this is on a purveyor's main or is it a service line?

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"My clients’ wishes are the center of my attention." -- David Guido, a contractor in Woodstock, N.Y.
New York Times, July 20, 2006

jmic

Day how long a run you talking ? Size pipe ? Come on man you should know the routine by now. Where's Nick when you need him ?

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Joe

dayexco

3300 l.f. of 6" class 200 IPS sized pvc and in a granular soil. we're losing about 4 gpm, won't expose itself

__________________
someday, i'll be as patient as Nick.

jmic

Hate to be a PITA but how deep are we talking ? Don't even know if this is feasible but what if you pumped steam from a steam cleaner into it and then shot the area with some sort of inforead camera.

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___"Remember You Never Get A Second Chance To Make A First Impression"______________________
Joe

Double-A

By me on that one. I have no experience chasing leaks on that large a line.

__________________
"My clients’ wishes are the center of my attention." -- David Guido, a contractor in Woodstock, N.Y.
New York Times, July 20, 2006

dayexco

7' of cover on the pipe, was just googling and found out there are methods of injecting either helium, or hydrogen into the main, and using a "sniffer" to find it. we've tried the audio "earphone" type, but way too much side traffic to hear anything.

__________________
someday, i'll be as patient as Nick.

Steve Manning

Can't you narrow it down in between valves on the 3300 lf

dayexco

there are 2 valves...where we start, where we end.

__________________
someday, i'll be as patient as Nick.

Steve Manning

Back in my inspection days I've seen a contractor install a valve in the middle and go at it from there until they can isolate it more closely. But that was a 50 plus mile long job with five crews and probably a drop in the bucket to them. Probably a job specefic decision. I guess it depends on how much money it is costing you a day. Are you still mobilized?

tgeb

I wouldn't go with Hydrogen, one stray spark and you might be reinstalling the whole thing.

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Tom

www.gebcon.com

TMatt142

Shut down traffic for about a half hour!!!! Joking....maybe? We actually did that on a 100ft section of 24" so the guy with the earphones could find the leak. That, or have them check it at night when traffic is at it's minimum.....Sorry, I tried. Anything works cept for digging it back up one joint at a time!

threaderman

I know it's 7' deep but unsure on the compactness.How about walking the line and probing for the wet spot every so often.You may hit a water pocket?!They still walk gas lines.

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dayexco

this is in a new roadway. we had to have 95% of standard proctor density wise, with soil tech's taking tests all the time. it's HARD!!

__________________
someday, i'll be as patient as Nick.

Tim Doyka

Just keep pumping it up hopefully it will surface, try a leak detection service they are pretty good with our experience, we have pushed rods down in the ditchline the water will its way out.

If you have any fittings dig them up for the listening service to get on to listen.

pvc is hard to listen on what is the pressure you are running with.

On shorter runs we have dug up every joint

Tin Cup

walk parallel to the main line you suspect is leaking, about 5' away on both sides with "divining rods". just us coat hangers, about 12" long with 90 degree bend for a 4" handle, hold them loosely. you are looking for the water running away. Don't believe me. walk over where you know the main line is and see if they respond. Done it many times, just as deep.

Tin Cup

firemike

We hired a company that specialized in leak detection. I took over a housing community construction project a few years ago that was losing water. It took the tech three nights between 1:00 am and 5:00am (quietest time, the project was between a major highway and major street), but he found two main leaks, three leaking toilets, and several leaking sprinkler valves.

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-Mike-