Finding a water leak in a buried line

[imarobot]

I have a underground pvc water line that has sprung a leak somewhere. The line runs from my house to chicken coop is about 150' in length. and is buried 4-5' below grade below the frost line. Is there a way to find this leak without randomly digging holes?

 

[Scm]

I have the same situation. But only have too dig 2'. I was thinking of installing a ball valve half way down the line to test each side and narrow down the amount needed to dig.

 

[Speed25]

I'd use a soil probe. Usually you'll feel a change in resistance when you hit wet, muddy soil. If you think you're in the right area, after probing, I'd try sticking something down the probe hole to see if it comes up wet.

 

[Tughill Tom]

There are ways, but can get costly. IR Scan, Sonic, Ect. I'd just install a new PEX line next to the old one and call it done.

 

[jaxs]

I assume you have looked for wet spot in soil. Few lines are more than 24 inches deep here so water usually surfaces when there's a leak. I've hired leak detection services that used something like a statoscope to find leaks beneath concrete. Not sure that works for a situation like yours but the fee is reasonable.

 

[D2Cat]

Most economical is as Speed25 mentioned. Probe down as deep as you can push it. Water soaked soil will have less resistance and soon water will bubble out the hole. Do this about every 10 ft. or so to hopefully find water coming to the surface. Get a real probe, not a pointed rod!

If you can't probe find a 2" auger and do the same thing. Best part of the problem is you're out in the open with room to work and not under concrete.

 

[NCL4701]

Good advice above. Another potential alternative.

If you or someone you know has the skill to find water underground with a stick or copper rods… Start at a known place on the pipe to make sure you’re on the pipe, not an unrelated natural water vein. Zig zag back and forth over the line tracing it until you get to a diffuse area (muddy underground). Work the diffuse muddy area to map the edges of the area and also to mark the entry and exit points of the pipe. Pull a line between the entry and exit points of the pipe to map the pipe location if it’s too muddy underground to be clearly discernible with the stick/rods. Start digging on the pipe’s route in the center of the muddy spot. Probe may or may not help in pin pointing more precisely, more likely to assist if the pipe has been in place for a few years or less. That whole process would take around 10 to 15 minutes with a couple copper rods and a handful of marker flags.

I’ve never been much with a sapling / branch. I’m pretty good with copper rods, but most anyone can use copper rods.

 

[biketopia]

My yard hydrant line sprang a leak back in March, it's just 1" Polly well line. It was put in by the previous owner; I had no idea where it ran. Thankfully, there was a curb stop inline to cut off the hydrant, so I had an idea how deep, and guessed a relatively straight line from A to B for location. I probed around for the wettest area and dug down about 3 feet to the line, kicked the well back on and looked for water to fill the hole from the left or right. Took 3 tries to get down on it, but it worked, just a little trial and error.

I work for the local water utility, and in the past, when helping out with main breaks, I've seen guys successfully use geophones to listen for where the water sounds loudest, or like NCL suggested, dousing rods.

 

[RCW]

It can be tough to find a small leak like this. All great ideas so far. Checking for wet spots along the route might be your best bet. If soils are sand/gravel with good drainage, may never surface.

I've used dousing rods myself several times. I prefer a crotched tree branch. I honestly don't believe in it, but it seems to work.......

If you know someone with municipal experience, some leak detection equipment can help. Unfortunately, it's easier to find a 50 gpm leak than one that's 5 gpm. 5 gpm doesn't make much noise.

 

[North Idaho Wolfman]

I have a underground pvc water line that has sprung a leak somewhere. The line runs from my house to chicken coop is about 150' in length. and is buried 4-5' below grade below the frost line. Is there a way to find this leak without randomly digging holes?

I'll correct you in that your water line is probably not 4 to 5 feet below the frost line as that would put the water line in at 8 to 10 feet.
Even at 4 to 5 feet deep your going to have a tough time finding a leak.
The most logical is abandon the old line and dig a new line using ABS or PEX as both hold up much better to all underground conditions then PVC.

 

[RCW]

Had a municipal leak many years ago. Couldn't find it. Storage tanks emptied. Dumped a couple million gallons in a gravel spot over a couple days, so probably 500+gpm.

Finally found it when a school bus caused a village street started to subside...Had to close schools for a couple days.

 

[NorthwoodsLife]

Look where the grass is the greenest.

But 4-5 feet down it may not make a difference. That's a deep water line.

Like others said, put in a new line. 2 feet should be deep enuf.

 

[North Idaho Wolfman]

Look where the grass is the greenest.

But 4-5 feet down it may not make a difference. That's a deep water line.

Like others said, put in a new line. 2 feet should be deep enuf.

Their frost line depth is 4 to 5 feet, so 2 foot would just freeze solid!

 

[FTG-05]

My neighbor has perpetual problems with leaks on his ~3520' water line from the water main and meter to his house. Every time he has a leak, he digs it up and splices in a ball valve, making it easier to isolate the next leak. I bet he has texted/called me a half dozen times to go turn his water off at the meter in the last 10 years. That's just the leaks I know about.

 

[NorthwoodsLife]

Their frost line depth is 4 to 5 feet, so 2 foot would just freeze solid!

In NH? Wow, I didn't know.

Ok, another 5' deep trench then.