copper water service corroding

[skillz]

I've had a contractor friend contact our company about a project that his company completed 18 months ago that has had some problems arise recently.

They completed a water main project and installed all water services. The Village has called him regarding leaks with these services, although they didn't know the reason why.

The contractor went out and dug up the locations of the leaks and found that the copper water services have corroded and are leaking already. Keep in mind this has only been 18 months since project completion.

We're baffled. Does anybody have any ideas what is going on here?

The location is a north suburb in Chicago.

 

[unclesyd]

Could you comeback with a little more information.
Where in the piping is the corrosion?
What does the corrosion look like?
Could you post some pictures?
Was this a previous industrial site?
What is the source of the water?
Any other information would be great help.

Having said all of the above I think you should be looking for a Corrosion Specialist/Consultant, ASAP

Still comeback with requested information.

 

[EdStainless]

There are a number of papers on copper.org that deal with this topic. There is a range of things that could be happening. Is the corrosion internal or external? At joints? elbows? What about other buried utilities in the area?

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[mauner]

The corrosion rate for copper stabilizes at a relatively low rate after the passive oxide layer is established.

Accelerated corrosion rates can occur when the fluid velocity is great enough to "wash" away the passive oxide layer.

A general rule of thumb is:

4 ft/sec for copper
9 ft/sec for 90-10 copper nickle
15 ft/sec for 70-30 copper nickle

If the engineer was accustomed to using the higher velocity limits and pressure drop associated with commercial steel pipe then you could have a problem using copper pipe.

 

[skillz]

This is Lake Michigan water. The corrosion appears to start right at the flare of the nut that screws into the shutoff valve. It looks like a typical 1" of 1 1/2" copper water house service.

I do have pictures, but do not know how to post them here, and I do not have a website where I can put them up on. Does anyone know how to post them, or give me an address to send them to for more advice?

 

[kenvlach]

All the comments are relevant, but perhaps most crucial is the pH and composition of the water. A similar rapid corrosion of Cu plumbing occurred in a California subdivision due to acidic well water.

The following link gives compositions of Milwaukee [TDS = 147 ppm, pH 6.4] & suburban Chicago (DuPage County) water [TDS 664, sulfate 411 ppm, pH 6.2], plus membrane-filtered Milwaukee water for beverage use. The filtered water is lower in both pH (4.6) and TDS (26 ppm), so would readily dissolve copper.

http://www.gewater.com/library/tp/702_Advances_in.jsp

 

[unclesyd]

Here are two sites for posting pictures.

http://www.flickr.com/

http://www.tinypic.com/

 

[metengr]

I live in the Chicago land area and have copper plumbing in my house with a ¾” copper supply line. We have been on Lake Michigan water for 15 years. There should be absolutely no problems with the water supply if everything is correctly plumbed and you have brass fittings.

 

[skillz]

UncleSyd and others -

I uploaded them at

http://www.tinypic.com

Search for images CopperCorrosion1 and CopperCorrosion2 and you'll see what I'm talking about in this case.

http://tinypic.com/tags/?tag=CopperCorrosion1

http://tinypic.com/tags/?tag=CopperCorrosion2

Metengr is right, this is Lake Michigan water and should not have any problems with pH. I could see it in some far NW or SW outlying suburbs that have well water, but not in this particular community.

 

[skillz]

Here are some more pictures, you can see what's going on a little better here. Any feedback you all can provide would be great. Thanks

http://i1.tinypic.com/s18cpz.jpg

http://i1.tinypic.com/s18dh4.jpg

http://i1.tinypic.com/s18dnq.jpg

http://i1.tinypic.com/s18dtw.jpg

 

[EdStainless]

Stray current / Galvanic issues? That is what comes to my mind.
Yes, I would double check the actual flow velocity and hte actual pH.
But this looks more serious to me.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[metengr]

Very interesting pictures. It looks to me that the problem is starting at the end of the flare and leakage develops between the brass nut and the OD surface of the copper tube. It might be that during flaring or during tightening of the brass fitting you are tearing or splitting the end of the flared tube causing a preferred leak path under pressure. The erosion will destroy this evidence.