Underground Water Leaks 5

[msquared48]

I have a client who is losing water and the meter shows it when the house is turned off - 1" meter still runs.

If the leak does not show itself at the surface, is there any common way to find the leak, short of digging up the whole line and replacing it? Don't want to do that as the trench would be over 1000 feet long. This line was installed in the mid 80's so and there are no drawings, so even the horizontal location of the line is floating out there.

Mike McCann, PE, SE (WA)

 

[Ron]

Infrared thermography might show it.

 

[msquared48]

How deep can that sense Ron? What type of company would have that testing technology?

Mike McCann, PE, SE (WA)

 

[chicopee]

Water department in my community uses an ultrasound meter with ear phones to find water leak several feet below grade.

 

[Ron]

Mike...chicopee is right. Most plumbers have ultrasound for checking this. Don't know why I didn't think of that.

Infrared checks temperature differentials, so would be limited in depth. Works well for hot water but probably not so good for cold water.

 

[hokie66]

It would be a good idea to install a valve at the end of the long line, near the facility. Then you can tell if the leak is in the long line or beyond that point, maybe under a building. As long as this line is, it might take several new valves to isolate the problem.

Most plumbers are clever in finding leaks. I agree that the ultrasound is the first thing to try.

 

[bimr]

Ultrasound is the correct tool.

http://www.uesystems.com/new/wp-content/uploads/2012/07/mj-article.pdf

You should look closely for green vegetation spots or wet spots.

The ultrasound may be expensive. If so, it may be more cost effective to bite the bullet and just replace the entire water line.

 

[LittleInch]

If the water line is PE, dig a hole in the middle, apply a squeeze off clamp and see if the meter keeps running. Then you only have 500ft to check. Repeat in halves until you get down to about 25ft then just dig it up.

Of it's iron or steel try this with a freeze block. If you can't get a freeze then the leak is past the place where you are, if you can even though there is flow, then see above.

Of course you still need to know where the line is so trace it using a detector for steel or divining rods for plastic.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[coloeng]

One method that I have seen is to fill the line with helium and then they use a helium sensor to find the leak. A locate company that I used at my previous job used this quite successfully.

 

[LittleInch]

what was the sensor? Crawl along the ground breathing and when you start talking like Mickey Mouse you've found the leak?

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[oldestguy]

There is a country plumber out our way who finds them by a doctor's stethoscope and setting a stake in the ground and listening to it when no wind, as at midnight. They also listen on any fittings, as a shut-off. Some good diviners also claim to be able to do it.

I'd try this. Shut off the line both ends and attach an industrial air compressor to it with increasing air pressure, gradually. Perhaps along with listening devices, as mentioned above. Shut off compressor and use the tank for a few minuted of high pressure, no noise then.

 

[dicksewerrat]

Once you trace the line, And know it's approx. depth, you can listen for the leak. Drive a steel rebar to within a foot or so of the line. Put a stethoscope on the rebar. You can test this by putting the rebar on the meter. Start there and go about 50 feet for each test. Once you hear something go back and forward half the distance. Leapfrog back and forth till you get good sound. Dig there. The water will tell you which way you may have to move your hole.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[BUGGAR]

I like Coloeng's idea.
But use acetylene and walk the line with an open flame. When you blow up, you have found the leak.

 

[oldestguy]

While you are at it, fill with propane gas, with odorant. Use gas sensing instrument.

 

[dicksewerrat]

You need some 'witch wands' to find the line. Coat hangers bent in an "L" shape will work. But 2 3 ft long brass welding rods looks more professional. Hold the short section in your hands and point the long section forward. Walk over a location that you know has a buried pipe. the wands will cross at the location of the line. Now go over to your water line location and do the same at about 15 foot intervals. Mark those spots. Now stand over the line. the rods will cross. Now walk toward the second point you found the line. You will notice that if you stray off the line the wands will uncross.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[oldestguy]

There is a pretty good diviner in this area that stomps his foot on the ground also and tells us the depth. The City of LaCrosse swears by his work. However, I saw one confident plumber mark out the pipe location of a water service. It seemed right, but happened to be about 200 feet off as to where it entered the property. When digging for a garage, they found it, and of course broke it. The result was later they had to insulate around it due to protect from frost, since the depth below grade then was only a foot.

 

[LittleInch]

dicksewerrat,

That's what I do and most people look at me as if I'm about to cast a spell over them when I get my bits of bent wire out.

they do tend to find false positives some time, but have located plastic pipes and FO cables not picked up by the CAT scanners.

Plus of course it doesn't need batteries and is inherently intrinsically safe!

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[hvacpiper]

I'm stunned...... divining rods....am I missing the sarcasm?

 

[coloeng]

OK, the helium idea was good for a few laughs, but check it out on the internet and you'll find that it's a tried and true method for locating leaks.

 

[btrueblood]

Safer than using a flammable gas like propane. And ridiculously sensitive (you'll find every pinhole in every weld using a helium spectrometer).