Repeated Pinhole Leaks in NEW Copper Water Main

[mcoval]

Hello all, would greatly appreciate any help with this frustrating issue. Bought our house 2 years ago, it was built in the 40s. Late 2022 had a couple of pinhole leaks, one after another, in the old 108ft copper water main. On the advice of our plumber, replaced the entire water main with new copper and protective sleeve in Jan 2023 as it was presumably at the end of its service life. Fast forward to March 2023, we had pinhole leak in the new main line. Plumber was puzzled, repaired it under warranty. We have since had 2 more pinhole leaks, also repaired under warranty. Thats a total of 3 leaks in a 4 month old copper line. The leaks are in the straight copper pipe, not at the joints. I have sent off soil for testing and will send water as well. Yesterday I found out that 4 other neighbors in very close proximity have all had water main leaks since January, a few of them have had more than multiple leaks. Presumably most of them still have an old copper line, but still. What is going on here? (Photo attached is of the leaks in the new copper at 3 months)

 

[MadMadMrsM]

I'll be interested to find out what your soil and water testing found. After years of replacing copper pipes because of pinholes, it finally dawned on me that it might be the water. It is - our well water is acidic at 6 pH and eats through copper. I don't want to install water treatment so I've been replacing all the water pipes with PEX. I also have to replace the indirect water heater because the water has disintegrated the copper heating coil. I'll be putting in a heater that uses a stainless steel coil.

Good luck!

 

[Sponsor]

 

[Jeff H Young]

Corrosive soil and water are in so ca but never heard of it this bad. could be electrical issue, prop[per grounding ?
Ive had real good luck with Sch 40 PVC and with copper.
Not knowing much on metalurgy it looks like the copper is erroding from the outside and not the water causing it.

 

[ArayT]

Agree w Mr Young.
I had this issue on a house years ago and after I added a short piece of PVC between the water heater and mains the issue stopped. I still have the house (rental) and no problems in 15 plus years.
rt

 

[mcoval]

Thanks for all the responses, just to “close the loop”…. Found out that the utility companies gas line was grounding through my water main…. So electrolysis was to blame. Oddly the gas line and water main have been located in the same place for years and years, but they recently did some work on the rectifier that charges the gas line, so presumably something went awry. The utility company has since shut off the rectifier, will replace the entire gas line with poly tubing that won’t require a charge, and will hopefully be reimbursing for the water main issues… fingers crossed!

 

[WorthFlorida]

Thanks for all the responses, just to “close the loop”…. Found out that the utility companies gas line was grounding through my water main…. So electrolysis was to blame. Oddly the gas line and water main have been located in the same place for years and years, but they recently did some work on the rectifier that charges the gas line, so presumably something went awry. The utility company has since shut off the rectifier, will replace the entire gas line with poly tubing that won’t require a charge, and will hopefully be reimbursing for the water main issues… fingers crossed!

A charge you mean a DC electrical voltage was applied to the gas pipe to prevent electrolysis in contact with copper?

Something I learned over fifty years ago why the traditional phones (land lines) were -48v's DC. When trolly cars were all the rage in the big cities like NYC, underground telephone cables were made of lead sheathing with paper insulated copper wire. Trolly cars used over head power but the tracks were ground. There was an electrical charge between the cables and rails, changing to a negative voltage took care of the problem.

 

[JohnCT]

...our well water is acidic at 6 pH and eats through copper. I don't want to install water treatment so I've been replacing all the water pipes with PEX.

You would need to remove all bits of copper, brass, and steel to stop acid corrosion issues, and you'll still have some issues with fixtures and valves.

I had the same low pH problem and repiped with PEX to replace my pinholed copper, but I also added an acid neutralization tank that uses calcium carbonate media (safe) because I didn't want PEX stubouts. I installed new copper stub outs to the PEX after I added the tank.

John