Water Leak Detector

[ronsimpson]

I have a long run of PVC pipe with a leak. It is 4 to 5 feed down in the ground.
It will take a months wages to dig it all up. It is cold and the grass is asleep so I don't see where the leak is by looking for green grass.
I can't find a soft/wet spot.
I can pay a leak detector company $300 to find the leak. I can get a leak detector for $300 that won't work or $1000 that will work.
Most leak detectors are a microphone and a battery powered amplifier. They listen to the sounds in the ground.
I have many audio amplifiers. None with battery power. I don't have 1000 feet of cord.
I have many mid to high end microphones. None are built to sit on the ground.
When I dig a post hole in the ground I can hear the water flowing as soon as the microphone is completely in the hole. I don't want to drill 500 holes.
Any ideas? What type of microphone?

 

[KeepItSimpleStupid]

Old way. Use GPRS: **broken link removed**

https://en.wikipedia.org/wiki/Ground-penetrating_radar

 

[JimB]

I would try a different approach, I would measure the earth resistance.

Two possible methods:
One
Make a connection to the water in the pipe, ie connect a wire to a metal tap or union on the part of the pipe which is above ground.
Using a resistance meter and a long length of wire, walk along the pipe run and probe the ground surface looking for the lowest resistance.
This method will (hopefully) find the shortest and hence lowest resistance path between the hole in the pipe and the ground surface.

Two
Using a meter and two ground probes, walk the pipe run and measure the resistance between points about 10 feet to each side of the pipe, again looking for the lowest resistance.
If the ground is of uniform composition this will (again hopefully) find the wettest patch, and hence the hole.

JimB

 

[4pyros]

put the mic in a bowl or a dish like a stethoscope.

 

[jpanhalt]

I had a 3/4" pipe going from the barn to pond (ca. 200 ft.). Using regular PVC plastic fittings, I fashioned an adapter to my compressor QC fittings. Then applied full air pressure. It was only a couple of feet deep, but you could hear the air sound at the surface. That would probably not work if the pipe couldn't be closed at one end to allow a little pressure to build.

John

 

[Reloadron]

There are places like this one that rent leak detector units. No clue as to the cost or if they rent what you need.

Another possibility would be the use of an accelerometer as a microphone for leak detection.

Accelerometers similar to those used for earthquake detection or another possible is find yourself a cheap guitar pickup and mount it to a section of hacksaw blade. Then get yourself a piece of rebar and drill and tap the rebar so each time you drive it into the ground you can screw the pickup to it. Use a small cheap battery powered amplifier or use a Instrumentation Amplifier and build a simple amp. There was a time when Radio Shack sold basic battery powered amps for a few bucks ready to go. Don't know if they still exist. The accelerometers pictured have 10-32 screw mounts on their bases and the one in the center top has a magnetic base mounted to it.

Anyway, a few things to think about....
Ron

<EDIT> Where I mention using a guitar pickup I am not talking about a $1,000 unit but the cheap pickup units that can be used with an acoustical guitar. Some of these things also have a basic pre amplifier powered with a 9V battery included. I forgot just how much a high end pickup can cost, I am thinking cheap here as in $10.00 flavors. </EDIT>

 

[ronv]

For a little project you might try a high gain electret amp mounted inside plumbing plunger. Rectify the output so you can measure it with a meter.

 

[Reloadron]

For a little project you might try a high gain electret amp mounted inside plumbing plunger. Rectify the output so you can measure it with a meter.

I like that!

Ron

 

[killivolt]

For a little project you might try a high gain electret amp mounted inside plumbing plunger. Rectify the output so you can measure it with a meter.

I think your onto something there "ronv" be interesting to an experiment. I think it would act like a stethoscope.

kv

Edit: Might get you into a 10ft differential either way. Measure the plus and minus and hit it dead center.

 

[ronsimpson]

Thank you KeepItSimple. Informative.
I tried a poor mans ground penetrating sonar. I took a 100 pound log and dropped it on the ground in many places. Some places do have a different sound.

JimB. Last time I tried ground resistance. I had to pound down copper ground rods. My water table is about 3 to 4 feet down and all readings were very small. In the act of sending a rod down I can find soft spots. Last time I found poking the ground with a probe (with out the meter) worked best.

4Pyros. "put the mic in a bowl or a dish like a stethoscope." AND RonV "plumbing plunger" I am going to work on this today. My neighbors already think I have problems in my attic. If they see me toilet plunging the ground they will know I have problems.
a) The pipe is in a tall grass field. Some of the leak detectors come with a microphone connected to a long steal rod that reaches through the grass and pokes into the ground.
b) In my farmers news letter; On man made a 3" PVC pluming pipe about 5 feet long. He puts one end on the ground and tapes a paper cup to the top end. Then attaches a doctor's stethoscope to the cup. Something like Killivolt said.

Jpanhalt. I have read that air pressure makes a much higher frequency noise. I need to go to the road and turn off the water supply or I will be pushing water back into the main line. The water company has made it very clear that they do not want their water back. I think it is a good idea.

ReloadRon: I have gotten rental quotes. For the price of one month I can buy the machine. One weeks rent plus two way one shipping is about 1/2 the price.
You have good ideas. I am looking for a microphone that suction cups to a window glass. Radio shack had them years ago. (acoustical guitar mic) I like the idea of mic/accelerometer/guitar pickup on a metal rod. One leak detector uses an accelerometer because they only are looking for low frequency noises. Other detectors are looking for very high frequency sounds. I believe the high frequencies travel through walls but not ground.

Thanks RonV. I have a old automotive PA amplifier. Last week I modified the mic inputs to work with modern microphones. I can hear the water flowing when the MIC is in a small hole in the ground. Right now the amplifier is powered from a battery charger and hundreds of feet of extension cords. I am charging up a small tractor 12 volt battery to power the amp. I need to attach a microphone to a steel rod. Load everything into a child's little red wagon and go for a walk.

Thank you all.
The temperature is dropping and snow will be here in 24 hours. I need to get going.

 

[MikeMl]

...
The temperature is dropping and snow will be here in 24 hours. I need to get going.

Watch along the pipe route as the snow begins to fall. You might be able to spot where the leak is because the snow melts there...

How about pressurizing the pipe with an air compressor (about 100psi).? Air will leak faster than water, so may be audible, or visible, especially if the ground is wet with rain or melting snow...

 

[ronsimpson]

Here is what I need to connect to a steal rod. Guitar microphone (clip on)

 

[ronsimpson]

Watch along the pipe route as the snow begins to fall. You might be able to spot where the leak is because the snow melts there...

Good idea!

How about pressurizing the pipe with an air compressor (about 100psi).? Air will leak faster than water, so may me audible, or visible, especially if the ground is wet with rain or melting snow...

The PVC is 30 years old and very fragile. My water pressure is low, being at the end of a long line, miles form town. I agree air pressure will change things. I am thinking about 30 pounds of air or about what the water pressure is. If I go that rout I will close off both ends of the pipe and slowly bring up the pressure. From past problems, the pipe is split the long way about 1 inch. If I drop the pressure by 5 pounds the flow stops. I would increase the air pressure slowly until I get good flow. I really want the (pipe split) to make noise not split somewhere down the line.

 

[Externet]

Good idea!

The PVC is 30 years old and very fragile. My water pressure is low, being at the end of a long line, miles form town. I agree air pressure will change things. I am thinking about 30 pounds of air or about what the water pressure is. If I go that rout I will close off both ends of the pipe and slowly bring up the pressure. From past problems, the pipe is split the long way about 1 inch. If I drop the pressure by 5 pounds the flow stops. I would increase the air pressure slowly until I get good flow. I really want the (pipe split) to make noise not split somewhere down the line.

Hi Ron.
Contact your municipal/county water crew; in my location they are very friendly; will do almost anything to please the neighbors for the sport of it, even after hours/weekends. They have all the best sensing equipment you will not have to buy and all the experience that cannot be learned before snows today. Will be more than paying with beer and pizzas, will be anyway well worth.
For an existing old PVC pipe, after you excavate, may find you want to replace its whole length to not have the same problem soon. New pipes are sturdier; and the municipal crews have the 'toys' to pull the existing one lengthwise while feeding a new one tied to the old being removed and know how to do it fast. Perhaps also leftovers from big spools available cheap.

Continue with your tactics, but in parallel contact the municipal crew anyway in case you end chasing your tail while scratching your head with one hand and the shovel in the other... under snow... into the night... and cold... and no water supply...

If removing the existing pipe pulling from one of its ends breaks it at the leak point; you will have the exact location measurement to dig at the break point.

 

[ronsimpson]

The water supplier said it is my problem. They do not help. It is my problem form the meter on.

If I replace more the 50% of the pipe I have to have the government come inspect the project. (permits) I have to have the entire trench open for the inspector to measure the depth. I can not cover up anything even in the cold. Any splices in the pipe must be glued or soldered. No quick splices. No threaded splices. This time of year the water table is about 4 feet down and the pipe must be more than 4 feet down. So I have to pump hard to work. I wan to use 1.25 or 1.5 inch flex pipe but I can't fine it in 1000 feet roles. Two years ago they told me I can't splice that pipe underground. I have to bring it up to splice. I don't want to use more PVC when flex pipe will last longer.

If I had my choice; I want to push a cable inside the old PVC. Dig out both ends. Huck a tractor onto the cable and pull a 2" flex pipe, which will follow the old pipe. (it will kill the old pipe but I don't care) I have seen this done with a cat tractor. I have done similar with 1" and 3/4" pipe and for only 100 feet.
_____________________________________________________________________
Got my 12 volt PA amp working with a small tractor for power. I am using 150 feet of wire so I can travel +/- 150 feet at a time. Using a head phone and the wrong type of microphone connected to a copper ground rod. I can hear the trucks on the highway one mile away. I can hear 100s of geese overhead. The neighbor eats geese so this morning he is blasting away with his cannon. A fly landed on the mic and hit the fly with my hand. (all very loud) There is not wind today which makes this much better than last try. No real luck yet. I will leave for town soon. I want to get a guitar microphone. (see post #12) I need to get wind off the mic and mic cable. I am also working on an insulated box that might keep outside noise down.

 

[KeepItSimpleStupid]

Here is a 500' roll. https://flexpvc.com/cart/agora.cgi?product=5_Flex_PVC_Pipe_1-1/2_inch

The same company states: "Requests For Quotes" for over 5000 fittings or 2000' of flex pvc should be emailed to them.

 

[Externet]

The water supplier said it is my problem. They do not help. It is my problem form the meter on.

If I replace more the 50% of the pipe I have to have the government come inspect the project. (permits) I have to have the entire trench open for the inspector to measure the depth. I can not cover up anything even in the cold. Any splices in the pipe must be glued or soldered. No quick splices. No threaded splices. ...

That is what pisses me big time.
It is your problem being beyond the meter but they still want their spoon in your plate with permits, inspections and done their way, and collect fees.

Yes, the no-trenching pull is a convenient way; and using that PEX pipe. Hope you solve it. Just watch Murphy, he never sleeps.

----> https://www.diychatroom.com/f7/running-new-main-supply-meter-pex-pvc-24638/

 

[ronv]

Bet your neighbor is wondering why you are pulling that tractor with the little wire.

 

[4pyros]

Neighbor thinks he is looking for gold

 

[alec_t]

Tell your neighbours there's gold down there and they'll all bring their shovels and dig the trench for you .