My water line is leaking...again!

[Gravydog]

I've lived in my house since new, 1978. Several years ago I got a huge water bill from a leak in my supply line (140') with no surface indications at all. I know the path of the line and I rented an amplified stethoscope to look for the leak. I got close to it due to the sound of tinkling gravel since the leak was big and our water pressure is 100+ PSI. When I dug down I first found a splice in the line and near that towards the meter was a crack in the 1" black poly line where it had some dents, almost like from a pick or bar? I also noticed that the line from the splice towards the meter looked really scraped up and all scratched up lengthwise. The line towards the house looked fine. My theory is that they used some old line they pulled out of the ground someplace to save money, terrible job. I replaced a few feet of the line using a new bronze barb and everything seemed fine until the next year when I got a new leak and this one showed quickly on the surface. I used a stethoscope again and found a new leak closer to the meter in the salvaged line. It was a longitudinal crack from the inside out. I knew at that point that I had to dig up from the original splice to the meter and replace that line and I did. The line at the meter was like a bronze barb screwed into a couple of sweated copper fittings and only single clamps, etc. Terrible! While I was at it I teed into it to install a yard hydrant. So, everything was good again or so I thought. Now, months later, I got a water bill for double and when the house valve is shut off the spinner in the meter still turns very slowly. I had the thought (and hoped!) that possibly the hydrant might have a small internal leak from the inlet to the drain. I pulled out the stem and found a slightly abraded section on the rubber plunger. I got a kit and replaced the plunger but it made no difference at all.

So now I need to find the new leak! I doubt it's in the new section of line and fittings, and the remaining original line of 150+ feet goes under pavement and landscaping. The leak is so small that there's no way I'm going to hear it even with a stethoscope with my 73-year-old ears. I'm wondering if there is some great technology out there that leak detecting companies use to track small leaks down? And how do I find someone capable and reasonable to do the work? (I will contact Terry Love Plumbing to see if they do this work and can pull a new line if necessary.)

Open to suggestions about finding the leak and replacing the line, etc. Thanks in advance!

Rob - in Bothell

 

[John Gayewski]

Black poly is bad news. It's likley polybutylene and has breathed its last breath.

Hate to say it but it's time for a new line. Get IPS or CTS sized pipe. Cts is easier to work with fitting wise.

 

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[Gravydog]

Thanks for the reply. Reasonably certain this is HDPE. I rented a high-end leak detector and listened all along the pipe path. I heard various rushing and rumbling sounds along with a repetitive but irregular timing "bonking" sound, quite loud. Kind of like bonking a plastic bottle on your head. I was hoping the leak was at one of my previous joints and the sounds seemed louder over the tee I had put in, so I dug that up first and it was dry. Maybe the the bronze tee radiates the sound better than the plastic pipe? Next I dug up the point of the original splice, so glad I made a video of the piping before I buried it! It was dry too. Lastly, I dug up the foot of the yard hydrant and the drain hole is not weeping at all. So I seem to have eliminated all of my previous work. I listened more with water pressure and then I drained the line and applied 100 psi air into it. Still wasn't able to zero in on anything. Then I tried listening with no pressure at all and it sounded about like before, rumbling and bonking included! I live at the end of a quiet cul-de-sac so I have no idea where this noise and bonking is originating. In fact, I checked at my neighbors' houses and it's even louder. I'm convinced now the leak must be in the old poly pipe to the house, a run of 100 feet to where the splice to the new piping is. Naturally I don't want to disturb my driveway and landscaping so the idea of pulling a new line through the old one is appealing. Copper or PEX or what? I have to figure out how to connect a pulling cable to the new tubing to pull it.

 

[Gravydog]

It was very tough but it's done! I went with PEX A and made a special barb that would hopefully be secure in the pipe but not expand it very much so we could pull it through the one inch poly. Here it is:

At the house end I had to dig a lot to find the transition from the poly to 1 inch copper from the house. I had a long enough roll of 12-gauge Romex wire and I vacuumed a string through the poly and used it to help pull the Romex through. I put the barb in the end of the PEX and attached the wire. We squirted a bunch of wire pulling lube into the poly pipe and started pulling the PEX, adding more lube along the way. The friction grew more and more from the curved PEX dragging in the poly and near the end it was all two of us could do to get it the last few feet! Out of 100 feet of PEX there was about 2 feet left over. I attached one end to the 40 feet of poly pipe to the meter that I installed a couple of years ago for a previous repair. The copper at the house was pretty crusty and not quite round but I got it shined up and as round as I could get it and tried to sweat on a copper reducer but when it was all hooked up the water just sprayed from my joint! I tried removing it, adjusting the fit, plenty of flux and solder, four more times! Never worked so I went and bought a high-buck bronze compression fitting which was more forgiving of imperfections in the fit as long as the pipe was smooth. Finally success! I will bed the exposed PEX in sand when I backfill. In case you're worried about the use of 3/4 PEX in the formerly 1 inch service line, for temporary service we connected to our neighbor's outdoor wall spigot and through over 100 feet of garden hose and through my hose reel and you couldn't tell any difference in water flow in my house. That's what 100+ PSI of water pressure will do for you. My house was built in 1978 and has no pressure reducer.

 

[John Gayewski]

Wow. Nice.