Multiple holes in water main

I bought a house last fall that I am fully renovating. In November I had water coming up through the front lawn so I dug it up and patched the hole.

In mid March I noticed the same thing happening again in the same spot. This time I dug a much larger hole. It is about 6 ft. long along the main starting about 4 feet in from the shutoff at the street. When I got down to the pipe I found 4 patches (including the one that I put on), spaced 12-14 inches apart. The new leak is about 10 inches from the most recent patch, closer to the shutoff at the street. It is perfectly round about the size of a pencil eraser.

When addressing the first leak I fixed we found that I had an open neutral on the electrical service. The power company came and replaced the drop and all of the wiring in the house has been replaced so that situation is remedied.

My question is, how do I fix this so it won't happen again?

I would install a new line from the meter to the house, it sounds like that one is old and in need of replacing. What kind of pipe is it?

It's 3/4 inch copper.

I'm trying not to replace it right now. Even if I have to, without remedying the problem the new pipe will most likely end up the same way.

Also, in the middle of the yard is a large pine tree that grows directly over it. That tree would have to come down to replace the main and I don't have the money for both jobs right now.

If it makes a difference, the first 18 - 20 inches of the hole were soil, after that it's all sand.

Is there codes in your area that say you can not use PVC Pipe? Also you should be able to re-route it around the tree. You can also wrap the copper in plastic to cut down on the corrosion. Aside from that you will probably just end up fixing leak after leak on the old line.

Are all of the leaks in portions of the pipe that come in contact with the sand? There could be a mineral in the sand that is causing the holes.

Also grounding of the electrical system could cause the same problem if it isn't grounded properly.

All of the main is in sand.

I have two copper grounds going from my panel to the water main where it comes into the house. One looks very old and one more recent, probably from when the panel was replaced 10 years ago.

I also checked the ground rod for the panel. It looked fine.

Could this be coming from stray current from another source?

I would consult an electrician for more detailed grounding questions. They should know what type of tests would be needed to check your grounding. If you could go with Chris' recommendation you would avoid these issues completely. Even HDPE plastic services are becoming more common and easy to install. Just be sure to get pipe that is rated for water service.

I picked up an amprobe yesterday and did some testing last night. I have a constant 1A on my water main. When I turn on the compressor it spikes to 14A and then sits at a constant 3.5-4A while running. Then I took the ground wire off the water main to find that there is still a constant 1A on it.

I need to contact the power company and get someone to come over and troubleshoot. It could be back feeding current from a neighbors house or a problem with the transformer on the pole.

Thanks for following up and letting us know what you found. This info can be used later to help others.