mike I also replaced my water line twice after I replaced my driveway spent over 8 grand the pipe is eroding from the out side and pin holes keep popping up I also have been told that its cause is from voltage there is a telephone pole at the foot of my driveway the wires run along the same line as my water pipe only the pipe is underground and the wires are above the pole is also grounded to my property I wonder if it is causing a high current creating the erosion lipa will not admet this I am at a loss i cant afford this any longer and i must rip my driveway up each time.

http://www.wssc.dst.md.us/copperpipe/copperpipewp.cfm

This is a good white paper on copper.

I would like to send you a paper about this subject. Please let me know how to do it. PS. The paper title is: "Corrosion of metals under the influence of alternating current". It was writen in February 1966 by James F. Williams from Northern States Power Company, Minneapolis, Minn. Saad Touma

It may be possible the leaks could have been cause by lightning. See the attached web site: http://www.roger-russell.com/lightning/lightning.htm

This is a common problem. It is being investigated all over the country.

IF the hole is wider on the inside of the pipe, it is caused by a change in the water treatment. Many water companies are using a new chlorination system that is suspected of causing this problem.

IF the hole is wider on the outside of the pipe, it is caused by soil side corrosion. This can be caused by the use of some hair driers in the home that use diodes to control the speed of the fan. The diodes create pulsating DC which will corrode copper or steel pipe. This may have even happened in concrete incased copper pipes.

I have seen entire neighborhoods of copper water service lines destroyed by a miss-wired cathodic protection system for a natural gas distribution system. The anode lead was inadvertently connected to the power neutral. Thus each home's neutral-to-water pipe bond caused the water pipe to corrode.

Some other sources of information: http://www.wssc.dst.md.us/copperpipe/copperpipewp.cfm http://www.epa.gov/nrmrl/wswrd/cr/pubs/wqtc.pdf http://www.epa.gov/nrmrl/wswrd/cr/pubs/awwa2005.pdf

http://www.corrosionsource.com/discuss2/ubb/Forum49/HTML/000012.html Just in case the link is deleted the text follows: After years of research, Dr. Marc Edwards, professor of Civil and Environmental Engineering at Virginia Tech has proven that the recent epidemic of pinhole & slab leaks in copper pipes is caused by the water. In order to comply with the Safe Water Drinking Act of 1991, water treatment plants began disinfecting our drinking water with Chloromines instead of Chlorine. This removed the Natural Organic Matter (NOM) from the water which did make our water safer to drink, but in turn made it very aggressive to the copper pipes.

With NOM in the water, the copper was able to develop a protective film coating. Like when you put a penny in water, it would eventually form a blue-green patina. As the protective film develops it protects the pipe from the water and the corrosion rate decreases. However, the changes made to our water chemistry have interfered with the formation process resulting in accelerated pitting and corrosion.

ref: http://www.nace.org/mponline/2004/0405018.pdf

Ten or fifteen years ago on my father’s place, the water well that was supplying the house was a 1/4 mile from the house. We had to replace the water line. We replaced it with copper. In about a year after replacing the line, it started to leak. There was so many leaks that we looked at some of the copper pipe we had left over and found bad spots in the pipe. There appeared to be trash in the material when the pipe with made. This may be their problem.

This reminds me of a problem homeowners had in Levittown, PA some years ago. This problem involved mostly heating fuel tanks. Most of the homes were in close proximity to electrical power substations.

When the problem was brought to the attention of the local electric compoany they installed targets designed to divert the stray voltages and currents to earth ground instead of through the tanks.

If the local electric company has not been involved, bring it to their attention. In most cases they will check out the problen with no charge to the home owner.

Mike, I forwarded this problem to our Mechanical Engineer (Dennis James, PE) for his input . His response was:

" I suggest they contact the Copper Development Association Inc. (CDA). Sounds like Beltsville, MD, where I live. In our community, the local water company (WSSC) changed the chemical treatment of the water, which facilitated the development of pinhole leaks. It’s a problem that is still not fully understood. CDA has been researching the sudden cause of pinhole leaks in copper piping for several years now. New pipes and old are equally affected."

You might find some information at: http://www.wsscwater.com/ces3/?q=orthophosphate It appears that the pin holes may be from the water itself. Personannly I would have suspected an open neutral in the utility primary or bad neuthral at the transformer.

I am from charleston S.C. there are several areas around charleston most specifically Summerville S.C. Where there has been a large number of Homes that have experienced this same situation. Here it has been mostly inside the homes causing large damage. It was traced down to defective copper piping from the manufacture. Another area is to find out what additives the local water company is adding to the water that could be causing this problem also. Hope this is of help. Another item I saw on DIY that flux left on copper pipes will also cause pin hole leaks.

We have had similar pinhole leaks in piping in the Marylland suburban area iin particular. Generally they have occured within the houses, not underground. It has pretty much been decided that the problem is caused by changes in the water treatment although the water company won't redily admit it. The changes were mandated by the federal govt., I believe, and the pinhole leaks in copper pipe were an unexpected consequence. I'm not sure where the situation stands now, but you might want to contact the WSSC (Washington Sanitary Sewer Commission). I'm sure they have a web site. If not, I can fiind the info. for you. I don't think it is a stray electrical current problem.

If pipelines are running parallel with cables this porblem couldhappen and the following checking shall be done before starting installation works: •Calculation of the induced voltage on the pipeline for the normal working conditions and earth fault condition. •Influence due to galvanic coupling between the installations. •Checking of influence on the pipeline cathodic protection system.,Cathodic protection usually used to reduce the electrolytic actions which may affect the pipeline , •Possibility of the accelerated corrosion of the metallic structures of the pipeline .

I have had a problem in my home, older, with these types of leaks. I have found out that in some areas of the country they have used some addatives in the water plants which have caused this problem. You may want to look into that issue also.

Mike,

The more logical answer is that the trench was backfilled with other than ideal material. If it was not clean backfill, ie < 3/4" materials, over time, the larger items will wear a small hole in the pipe with normal movement. We always try to utilize stone dust around utilities, including DEB conduits. It also allows identification in future excavation.

Dear Sir, I am an electrical engineer with a consultancy. I discussed this problem with a colleague of mine who is a public health engineer and we think that this problem is because of 1) pipe joint leaks 2) pipes damaged at the time of construction/ afterwards due to earth works 3) manufacturing defect in pipes Solution: Repair/replace pipe section, properly test and put the pipeline back in operation Hope this solves the problem. Thanks and regards.......... Anju

I remember reading a problem like this a few years ago and it had to do with the improper grounding of the electrical service. I beleive it was posted in the iaei magazine.

The problem of pin holes are due to the presence of different chemicals in the water, like magnesium, calcium, cholorine etc. When copper reacts with cholorine it forms copper choloride which is an acid that starts choroding the surface of copper pipe and creates pin holes at the weakest point of the pipe which normally happens to be joints of the pipe considering that there are no manufacturing defect in copper pipe itself.

Alternating current do not contribute to this problem because the electrolytic process is only possible with DC. (Direct Current)

We have experienced mysterious leaks in our county which has prompted an extensive study to find the cause. Here is a link to the news clip. Perhaps it will shed some light on our member's situation. heraldtribune.com/apps/pbcs.dll/article?AID=3D/20060514/NEWS/.../RSS01 Moe Biron Custom Electrical Systems Inc. Sarasota, FL

While non-electrical causes are most likely, an impressed DC voltage (from nearby corrosion protection systems, telephone system, etc) could cause such failure in copper pipes. This can be ruled out by measurement. We have also seen lightning and accidently applied high voltage to the ground or nearby neutral conductors result in leaking copper pipes.

If there is a defect in installation as seems most likely, the owners should sue regardless of limitations, as deliberate or gross negligence is likely to result a decent selttlement in any case, if the plumber has any resoures. Just get a really good lawyer.

YOU ARE CORRECT IN STATING THAT AC CURRENT CANNOT CAUSE THIS TYPE OF PINHOLE CORROSION IN A COPPER PIPE. 1 OF THREE PROBLEMS: 1- IMPROPERLY MANUFACTURED COPPER TUBING. 2- CHEMICALLY OR WATER PH LEVELS BEING SO FAR OFF THAT THEY ARE ERODING THE COPPER AT THE SEAM WELDS. 3-SOMEONE DRILLED HOLES INTO THE COPPER PRIOR INSTALLATION. I PERSONALLY HAVE SEEN ALL (3)

try document: effect of grounding and electrical properties on water quality, journal-awwa, 2002,vol 94,no5,pp.113-125.

I believe copper piping comes in three thicknesses, "K", "L" and "M". If my memory serves me code specifies that type "K" is the only one approved for direct burial. The type is written on the side of the pipe similar to wire. You probably still have additional issues but if they didn't install it to code you may have a legal recourse.

Mike Did they have a chance to look at the inside of the copper pipe and the outside of the Pipe? Was also wondering if there could have been some type of ground contamination in this area and if there were any contact by any other wires? Thanks John h ledger

possible wrong type of copper pipe. two types are used L and K one is used for heating and has a thinner wall. Consider using some type of sacrifical annode. Soil conditions will also have a reaction.

Your plumbers have not confirmed anything. What they say is merely their opinion. This is the same old story we have been hearing for years. There is no evidance that an alternating current on a water line leads to corrosion. If corrosion due to the water system being used as a ground were a problem what you are seeing would be widespread since this has been done throughout the country or many, many years. I would look at soil conditions, backfill and defects in the tubing itself.

Hi Mike, Type L (blueline) copper is the grade required for outside direct burial water pipe. Larger wall thickness and temper hardness over interior grade Type M (redline) reduces triboelectric static DC buildup erosion on pipe from frictional water flow and high chlorine corrosive effects combined. Stanford University had a study done on the local medical center near campus and results showed a copper leaching from copper water pipes and facility waste use to be well over 0.18 lbs per day. Remedies were mentioned to lower flow rates, water oxygen content and change water pH. (1991-1994 Copper corrosion study by Kennedy-Jenks Consultants, Palo Alto, CA). I hope this helps.

A few years ago in Mission Veijo, Ca. has this very same problem with a housing tract of approx. 300 homes. It was determined that the acidity of the soil was such that it was eating the metal. Copper, Galv and cast iron.

The developer/contractor had to replace all undergroung with PVC and run all copper up the side of the homes and through the attic.

Not sure is this is the case here, but maybe worth checking into.

Jerry

PVC pipe should have been used

I was involved in a similar situation where a brass coupler on a two inch soft copper water main had suffered a leak, due to the copper pipe becoming eroded away at the joint. A mechanic who used to work in the metal plating field seemed to believe this erosion was due to the copper water pipe having a voltage on it and being electricaly sacraficial, as in plating. I questioned the original soundness of the connection and associated the etching away within the fitting to the effects of a slow but steady leak, similar to what is evident on faucet valve seats when a leak will cut through brass and over a relatively short period of time, cut a groove right through and deeply into the valve seat. You may want to check to see if the unballanced service current is on the copper pipe rather than on the neutral at the service, causing the copper to carry voltage and be sacraficial. This was the suggested cause in my situation, but never varified.

The fact that the neighbors are experiencing the same problem points to the copper pipe. Pinhole leaks are generated from the inside out. Electrolosis would attack the exterior of the pipe more so arould the joints. Are the pinholes in the elbows? If the plumbers did not ream the pipe the water flow causes a ventury action that wears down the copper at an exponential rate. I work at UCLA in California and we had a whole new building go bad within two years of opperation. The homeowner may have to go to litigation with his neighbors against the builder/plumber. there is a statute of limitations of seven years. good luck. Gordon Webster

No Mike, more than likely is was due to lack of required \'reaming\' of the pipe ends, thus causing vortexing and therefore the most likely cause of the pin hole leaks. Ream the plumber....

It very well may be that it is in the pipe. Most people are not aware that there are three types of copper pipe there is type M, type L, and type K. The builder probably cut corners and put in type M or L when in actuality they should have put in type K which is a heavier walled copper pipe. As a result the pipe broke due to the shifting and settling of the ground as the new house ground settled. The builder figured that it wouldn't have to worry about it because the problem wouldn't show up until the expiration of their warranty period. However, if they put in the wrong material then they should stand liable for the damage--especially if it is consistent from house to house.

Mike is correct. Current running through the pipe does not affect the copper as to create pinholes. The problem is not "bad copper" either. THe problem is simple and quite common. The water is what we call active and eats through the copper. Fixing the pinholes is foolish because you are going ot get more. Copper should not have been put in to begin with. Bottom line: the copper needs to be replaced with polyethylene.

We see this problem on occasion and believe it is from the plumber who used an acid flux and didn't flush the line after soldering. The acid will settle in the copper line and eventually eat a hole through the copper. If the same plumber did the neighbor's house then the problem repeats itself.

i had a similiar experience at my own home back in the early 90's. I has numorius pinholes in the copper piping under slab & in walls where the piping came up thru the slab. The cause was from a lightning strike near by, approx 100 yards, at a near by tree. The ground path/ strike from the tree to the home was obvious and this was the only solution that seemed to fit. This scenerio seems possible th this case also. just a thought

A friend of mine who owns a restaurant mentioned that the copper water was turning black and a few of his refrigerators had damaged copper lines requiring replacement. His flat screen TV's had been damaged as well, the TV technician opened the set and asked why the interior was black, (burnt)! This may be similar to the problem experienced by this gentleman in Tennesee. I noticed a few important issues concerning the grounding of his service. First, the ground clamp on the water main was loose, a current reading on the grounding conductor was 11-13 amps! Further investigation revealed an undersized service grounding conductor and taps off this undersized grounding conductor to other service switches. This situation caused significant damage to all the copper connections in this restaurant. I am sure this similar situation exists with this gentleman's house.

I found reading these comments most interesting! It seems there are at least two thousand possible reasons for the holes in the pipes. One could easily write a book with all these comments. Know what? it isn't any of these things-it's those damn lawn grubs-they'll eat anything........

I think the plumber that installed the main water lines to all these homes skimped on product quality.

as a licensed plumber and master electrician, I have never know leaking current to cause leaks in the copper pipes. My suggestion would be to double check all of the electrical connections and then pursue faulty pipe installation. The fact that neighbors are also having problems, suggest that maybe the same plumber did all of the installations

I have the same study that Mike Holt mentioned by the AWWA. While AC current will not cause corrosion of metallic water piping DC will. And it can be away from the house or towards the house. If away from the house, it will cause corrosion of the copper piping. If the piping is continuous to the water main in the street, the AWWA (American Water Works Association) recommends installing a 6-12" section of nonmetallic pipe at least 10 feet from the house (so the water service line will still be effective as grounding electrode) DC current can be caused from electric drills or hair dryers. Also, as I do a lot of work for a large municipal water system, and in our system we have a corrosion control treatment facility that raises the pH of the water from 7.5 to 8.5, as the low pH is corrosive to the lead and copper. This is a requirement by the EPA to treat some water if its considered aggressive and can cause corrosion. Check with your water supplier, see what the pH of the water is, and if it changes from season to season. Your answer will depend a lot on how large the supplier is, and hopefully they will have a water quality technican you can discuss this with.

I had the same problem with a kids camp I wired ten years ago. All sorts of water tests were done. It came back not to be the cause. One day at a local code class, an electrical grounding profession was there to explain grounding, I told him of the situation. He brought out his equipment and saved his findings. I went to the local power company and told them that they had a bad transformer or capacitor in the area and it was leaking back thruogh thier system. They would run a check of a one mile area from the camp. Two different crews said they couldn't find any problem. Since that time, the camp hasn't had problem since. By the way, the expert I used is retired and living in the southwest area of usa.

In Las Vegas Nevada we have whats called galvonic corrosion. The minerals in the earth under concrete slabs eat at unsheathed copper plumbing piping. This doesn't occure in all valley areas but rather on the downslope of the mountains. The cure is to sheath the copper pipes to the structure and run Wirsbo plastic plumbing through the attic to the fixtures. Not caused by electric currents.

Got this from a Mech. Contr.

We have seen electrolysis problems in copper pipe before, we have found that the grounding connection of the telephone or cable system has been on loose or simple come undone. Although in the Jacksonville area the water is so aggressive that it has been banned for use in residential systems, they to where experiencing pin holes and determination from with in. so I guess that it depends on the area you live in.

There is a remote possibility that the iron content of the soil that the pipe is buried in may be high and the current flowing through the pipe is aggravating the natural electrolysis of the dissimilar metals. It is proven that copper will corrode quickly if it contacts iron, steel, etc. While not an answer, it is something to check into. I am not an authority on this, but have seen this type of damage before. It certainly is something to look into. Especially if other houses in the area are having the same problem. If you can get a section of the pipe, send it to a lab and have the failure analyzed for root cause.

I would suspect that there is a high impeadence line to ground connection in the vacinity. This is allowing a low level of current to flow through the cold water pipes into the earth then return through the neutral ground link of the originating service for the offending circuit.

The damage to the pipes is due to the galvanic action from the charged pipe to the minerals in the soil. The pipes are being slowly eaten away. Induced current cathodic protection systems seek to protect underground pipes in the reverse.

The high impeadence line to ground circuit could be in a 240 volt dryer that needs a neutral, but is connected to ground instead.

If you clamp an amp meter around the ground electrode conductor in the three homes you might be lucky and find the culprit.

I'm no expert on this but I believe this problem could be caused by a direct current flow through the copper pipe.

Re:11/20/06 member needs help.Ther is probably a DC component to measurable AC on these water lines.We have had recurring problems w/ what we took to be electrolosis on copper water lines(hot water recirculation in an old dormitory with kitchen facilities).To make a long story short/examine all grounds(looking for loops or high resistance connections) and also verify that the telephone system is properly bonded.

There is a phenomena in refrigeration called stress corrosion. Evaporator copper u-bends experience this phenomena in an acidic enviornment Pinhole leaks develop in the outer portion (area of greatest stress) of the u-bends, when subjected to an acid enviorment.

The evaporator, on small deli sandwich makers and reach-in coolers, where pickles are kept, is subjected to this enviornment when the sandwich makers or other pickle users dont cover the pans with pickles or pickled peppers or anything else acidic like lemon juice.

The acid vapor from the vinegar, etc will cause stress corrosion --- it may take a year or several, for the copper to erode to the point where leaks develop . I have seen this phenomena on numerous occasions. The pinholes can be filled if not too bad-- I use soft solder with rosin core instead of silphos brazing rod as the copper is very weak at this point and the heat required for silphosing can cause bigger leaks-- but the best fix is to replace the evaporator and educate the user.

I would suggest looking at soil pH for a strong acid condition. If the copper used is hard drawn, which I suspect it is, there may be enough stress in the copper to allow stress corrosion to occur if the soil conditions are strongly acidic. I believe there are inexpensive soil ammendments that might bring up the pH. I would ask a good landscape maintenance company or geologist to see what they suggest for eliminating an acid soil condition. I think there are soil test kits at many gardent centers--- if the pH is much below 7, say 4 or 5, that might be the cause.

It may also be that the copper used in that housing complex came from a faulty batch to begin with--try to get a sample of the same material from inside the house and then send it to a metalurgist for grain structure analysis and susceptibility to stress corrosion Good luck Bill

Do they have pipelines in the area? Maybe a problem with the pipeline cathodic protection (DC current) and the copper pipes are acting as anodes?

Re the copper pipe leaks. One of the problems may be that the copper product is inferior. I have inspected several defective projects that had the same pinhole leaks and these lines were placed in the overhead. In this are, Souther Califonia, we've had tracts that had [perforated gas lines using black pipe - to be expected. Is the copper burried in a sand layer or could it be touching the screed buried in the cement? In all the years the UFER has been in use it does not seem to have affected the copper.

Mike, I agree. Use 2 ground rods, 6\' apart and bond to interior water metallic piping. DO NOT bond to the street side of the water meter.

Some years ago I owned a home that developed pin holes in the galvanized water piping. After replacing some pipes twice, I started checking with a clamp on ampmeter. Sure enough, the neutral was open. Fixed the open neutral and the pipe pin hole problem never reoccured.

I have been told by a good friend of mine that is a plumber that current passing through copper pipes causes pin hole leaks. His explaination from what he was told is that the minerals in the water cause the pin holes when they come in contact with the copper pipe that has current running through it. I'm not sure how that would happen, maybe it causes a mini short or the minerals burn out? I don't really know , but I know that many plumbers believe this.

In general, if this were a problem then a good part of the country should be under water due to water pipe leaks because some amount of current will follow parallel paths back to the source but in proportion to the impedance of those return paths. The writer might want to have the area checked for stray DC currents, soil conditions and water chemistry all of which can play a role in acting galvanically upon metallic piping buried in the earth.

Wow. There are quite a number of scenarios that can cause the pin-hole leaks in underground copper water pipe. Yes, electrolysis is responsible. Is it from the soil or the water?

Our AC systems are not to blame. Sometimes, the way in which we connect our electrical systems to earth can be the problem or make the problem worse, or (yep) fix it. As you replace the failed piece, have it analyzed to determine the source. Then see if galvanic (cathodic) protection will work for you. Contact your water company. See what they have to say. You’ll have to badger them to get to the water quality people.

One thing I’d really like to make clear; if you choose to have your home-owners insurance cover the cost of repair, be prepared to be dropped at the next renewal cycle or have your rates triple. I was dropped for about $5k in repairs for an under-slab leak (southern California) – the first time it happened. The only insurance that would pick me up was one that wanted three times the rate I was originally paying. Sure, it’s not $5k worth of premiums, but it’s monies I never would have believed I would be made to pay.

There bad part is a database of homeowners that have had water damage (maybe other types too) and have turned it over to their home-owner’s insurance. It’s called CLUE. Once you’re on the list, it’s three years before you’re back to normal rates. Look it up. Darn depressing information. If you can afford the repairs out-of-pocket, and they’re not too bad, I’d do it. It really does no good to ask the insurer up front. They’ll be less than truthful. My agent couldn’t believe it happened.

The second time it happened (several feet from the original site), I recognized the symptoms and prevented damage to the structure. And, as it happened a second time, I knew the problem was not an isolated incident. Now your faced with re-piping. Big cost. I chose an alternative solution. Not necessarily cheaper, but certainly a whole lot less invasive – and guaranteed for ten years. Try a company called ACE Dura-flo at www.aceduraflow.com or at www.fixmypipes.com. Either will land you at the same site. There is a ton of information online about the increase in underground copper water pipe leaks. I like, and kinda align with the idea that, as water standards have become more strict and water is subsequently cleaner, there are fewer organics in the water to facilitate the patina (copper oxide) layer. Some believe the patina was responsible for protecting the interior of the copper pipe, allowing it to last for a very long time.

I have no holdings in this company. I do feel comfortable recommending them. They do what they say they’re going to do, when they say they’ll do it. That’s pretty good these days.

I’ve thought about systematically re-piping at my leisure… with plastic. There’s some pretty neat home water distribution systems out there.

Good luck.

I think someone is selling bad copper pipe. Other contributing factors? What's the soil pH? How's the water there?

Save the pipe sections. If the whole neighborhood is saddled with this, maybe the pipe manufacturer should pony up. If it was 20+ years, but 4? You have to make better stuff than that.

I don't know the actual cause, but, my next door neighbor works for our county, and has for the last few years been replacing most or all of the buried oil tanks due to pinhole leaks in the tanks. He is an engineer, and tells me that the cause has been determined to be the fact that electric lines run close to the underground tanks. I will ask him if that is supported by some type of study. Hope that helps a little

I am far from an expert, but I do have some experience with pipe corrosion and cathodic protection systems. I know corrosion occurs when current flows off of the pipe and the electron loss gradually causes pitting and holes. Impressed current cathodic protection systems actually apply a direct current from the ground onto the pipe to keep current from flowing off.

check the acidity of the soil

I have done similar research and the results of my research are that numerous studies have determined that electricxal current flowing through copper does not cause pin holes or other destructive issues unless the current is greater than the copper can withstand. In the case of the copper water pipe we would be referring to a very large amount of current. A large enough amount that the pin holes in the water pipe would be the least of you problems.

Regarding the corrosion issue, In addition to my first post, it may be the underground tubing is type M instead of L or K. I copied and pasted the data below from Cerro http://www.cerrocu.com/hvacPlumbingTube.aspx website which is the first return that showed up doing a Google search. I suspect the problem could be the type of tubing used in addition to the stress corosion I mentioned in previous post. Type M hard drawn would likely be very prone to stress corrosion/pinhole leaks when used in an acidic soil condition (this is speculation on my part as I have not had direct experience with pinhole leaks of the type in question. Builder may have been trying to save money by using the least expensive grade ---metalurgical testing would seem a good next step in addition to soil testing. Bill

copied from Cerro Flow re. copper tubing, pasted within " " marks

"Typical uses include:

Type M – above ground residential and light commercial uses. (Sizes range from 3/8" – 8" diameter)

Type L – residential and commercial uses. (Sizes range from ¼" – 8" diameter)

Type K – underground residential, commercial and industrial uses. (Sizes range from 1-1/4" – 8" diameter)

Type DWV – ASTM B306: Used for drainage, waste and vents "

Have the incoming water tested by a water analysis lab in accordance to their recommended procedures (in other words, find out the proceedures, then follow them). Water pH may be too low. We have circumstances in Oregon where the water treatment plant must buffer the water to increase pH to prevent copper corrosion. I agree with Mike that electric current is not likely the problem. Could be flawed piping if the water tests ok. What kind of copper was installed? Water tube piping comes in three types: K, L, & M. Type K has the thickest wall and is recommended for underground applications. Type L is used indoors, above grade. Type M is the thinnest and should only be used for condensate drain piping, etc. above ground. The piping should be color coded for easy recognition. Type K - green; L - blue; M - red.

Several years ago something similiar occurred in houses near a utility substation when the local electric utility had a system fault. Seems that the copper water lines were making contact with the reinforcing mesh in the concrete foundation slabs. One theory was that the fault somehow induced a a difference in potential between the mesh and the pipe, which burned a hole in the pipe where it contacted the mesh. I understand that it is a code violation for the pipe to be in contact with the mesh. I believe the homeowner's insurance paid the damages.

Considering the wide variety of communities and major cities such as Chicago which have for decades utilized the water pipe system for a ground, with this problem NEVER showing up, I would say a bad batch of pipe, if it all occurs at one place in a relatively short time.

Highly acid soil could cause problems. Manufacturing defect is more likely. However, defective dimmers that produce a net DC bias on the neutral current could develop a net DC component on the pipe relative to the soil and enhance corrosion. A voltmeter from the Cu pipe to a remote ground rod should be able to detect a DC bias.

I Agree with Mike on this one. AC current doesn't do much with corrosion although Direct Current does. (Look at the battery cables on your car battery).

I live in Montana and there was a similiar situation here about 5 years ago. the conclusion was that electrical Current was responsible for the pin holes, but it was the result of the AC Current being rectified somewhat through certain minerals present in the soil (Silica, Mica, and Iron).

There was a lot of arguement about this, but it was the words of an Electrical Engineer that came to that conclusion. Down the street, there wasn't a problem because the mineral content wasn't present.

If grounding to the copper water service caused this sort of problem, we would have heard about it long ago. They probably have an acidic soil condition, not unusual. Often plumbers will wrap the copper pipe with a fibrous sheath to prevent this...

From the information presented it points towards an electrolis problem which could be caused by a local pipeline that has cathodic protection and is causing a current flow in the earth. If this is cause the copper pipe will be eroded on one side only i.e. the leaks on one side of the tubing which is caused by the copper being plated on one side the removed from the other side.

If the house has improper grounding system and is using the copper pipe, the an insulating section needs to be installed in the copper line before it enters the house. This will cause the currents to flow to the ground rod at the meter entrance.

A test can be made by disconnecting the copper water pipe from the house and connecting a meter to read the voltage between the house and copper tube. Next take a current reading. The data obtain from the readings can be used to better refine the problem and the solution to resolved the problem.

Hope this sheds some light on the issue.

P.S. Cathodic protection can cause large current flow in the ground and if it is nearby, you can expect it to be flowing in the ground.

I am a master plumber, as well as a master Electrician so I have encountered this problem a number of times in the past, It has always turned out to be bad pipe or acidic or caustic, soil or water.

There was considerable press a few years ago in the Carroll County MD area where home owners were experiencing this same problem in rather new developments. My recolection was that no final determinaton was made but several experts were of the opinion that it resulted from additives in the water supplied by the utility and the quality of copper pipe installed. If I remember correctly, some developments were impacted more severly than others although they were all using the same water. I believe there were comments about the utility removing some additives to the water supply in an effort to reduce the problem. Have not read any recent press on the subject.

I don't have any studies, but I would like to know if any type of metered testing has been done. I would have to ask if any of you have a swimming pool and is there any current emanating from it. There have been cases of supplied current allegedly using the earth to return to the generating station, but to my knowledge, it has not been "proven". We all know what electrolysis does to water molecules, so I could see a degree of reactivity being possible. I would also be curious to know when the other houses were built, and the water lines installed for comparison. Where did the K copper come from, and did the same company/supply house use a particular brand of copper? I might add that I am not privy to the mineral content of your local water, so I would also have to ask may there be a compound that would react with copper in the presence of electricity? I know Kentucky is cave country, and there is limestone in the strata for sure. Any rate, that is what I can think of off the top of my head. I will read further as comments are posted...

Mike, Since copper pipe comes in different thickness ratings,the pipe being the wrong rating for direct burial could be a possibility. It could have also been a bad run of pipe from the manufacturer. I have been attaching ground wires to copper pipes for 35 years and have never heard of pin hole leaks being caused by electricity,not that it couldn't be a possibility.

Here is a good link to the subject of "pin hole leaks" in copper pipe:

http://www.wssc.dst.md.us/copperpipe/pinholescroll.cfm

It was(?) a hot news item here in the Washington DC area a couple of years ago but it seems to have subsided greatly because our local water supply has "doctored" the water a little to put the brakes on the problem.

I have encountered this in New Mexico with High Alkali soils....Thats why plastic is used out here for the street to house piping.

I havn't heard of anything dealing with AC current that would cause such and issue plus Kentucky requires at least 2 ft clearance between power and other utilities.

In Washington State a seperate ground rod (actually two seperated by several feet are required for services, bonded as well to any and all metallic piping, steel structure, etc. If that state did not require a distinct ground, and the neutural was open for the neighborhood, a very unsafe condition could occur - that being a current carrying water line & differing soil conditions could corrode a pipe in just a few years - if not sooner. Comments?

The following link leads to an article in which Dr. Marc Edwards, professor of Civil and Environmental Engineering at Virginia Tech, has shown that the recent epidemic of pinhole & slab leaks in copper pipes is caused by the water due to recent changes in water sanitation techniques.

http://www.nace.org/mponline/2004/0405018.pdf

The following link leads to an article in which Dr. Marc Edwards, professor of Civil and Environmental Engineering at Virginia Tech, has shown that the recent epidemic of pinhole & slab leaks in copper pipes is caused by the water due to recent changes in water sanitation techniques.

http://www.nace.org/mponline/2004/0405018.pdf

I had pin holes in copper piping inside my first home I purchased. It started out as green spots on the copper. I made the mistake of cleaning it off and wound up with an all night job replacing it. It sounds as though the contractor through no fault of his purchased a bad run of copper pipe. That would be the manufacturer's fault, not the plumbers.

I'M NOT SURE IF THIS WILL HELP, BUT I WORK IN THE MARINE REFRIGERATED CARGO INDUSTRY. WE USE 3 PHASE, 460 VAC TO POWER THE EQUIPMENT AND WHEN WE INCOUNTER GROUNDING PROBLEMS THE COPPER LINES TURN REDDISH AND SEEMS TO DISINTEGRATE AND JUST ABOUT FALLS APART WHEN YOU HANDLE THE COPPER TUBING

If not an electrolysys problem(which I doubt seriously) I would ask if the water supply has done any repairs recently (within your vacinity) which involved chlorination to sanitize the work site. I recently encountered a similar problem - new pool, less than a year old. Heater pumps sucked up undesolved chlorine granules (used to shock the algea in the pool). Ate up the copper lines( chlorine and copper doesn't sit right to begin with). The other thing was entrained air inside the piping -"cavitating" - especially after the meter and smaller devices and fittings, created vortexs which often sounded like marbles in a glass, Won't take long to pit copper tubing.

Mike, In dealing with circulating currents in large motors it is very common for this current flow to cause pitting and pin holes on the bearing surfaces as the current moves across the air or oil gap in the bearings. It is possible the current flow itself is not causing his pin hole problem but the presence of a parallel path of sufficient low impedance that must push through some higher impedance medium ( wet earth ) to continue to flow, Ky soil is very rocky with iron ore clay mixed in. Good conductor for a parallel path. I'd try a good quality Ammeter and measure the currents at different points along the buried pipe. FYI - EC&M Sept 2006 had a great article on EMF and childhood cancers ( pg 36 - 40 ) is relating new study focus on children experiencing this ground current flow for extended times as a possible cancer causing agent. His home would have plastic drain lines so it may not be quite his issue but defintely and eyeopener for us macho tough guys who work with out the proper PPE (rubber gloves) while around energized circuits. Also had a good article on "stray currents" to continue the industry discussion. Keep up the good work Mike. God Bless.

Check on the ground acidity and/or electrolysys with the type of soil. We have this problem in Garland, Texas. It typical affects cast iron pipe. This is a problem in certrain parts of California and Neveda. Check about replacing with PVC or PEX pipe.

The only things I can think of at this time that might cause this problem is that there is too much stone in the backfill [it should have a sand base and cover] or there is something in the soil attacking the pipe -very acidic. If you find the answer, I would be glad to hear from you.

Al Fein

We have had this problem in South Carolina for some time. The end result is copper that is recycled for water piping has impurities, the size of a pin or smaller. A little green spot pops up on the pipe and then a fine spray starts. Most of us just remove the entire copper pipe system and install Pecks piping. Sorry, get ready to spend $2,500.00 to $3,000.00.

I had the same problem in the late 70s. Turned out to be electrolysis. The type of soil and mosture reacted with the copper pipe and caused pin holes. I had about 14 holes in three feet of copper pipe. The fix is to cut the bad section out and replace with PVC> I also cut about two feet out at the meter and replaced it with PVC. Problem was solved for me.

Make sure they installed type K or L copper if they used type M than you will develope leaks in about 4 years

Check out the AWWA Research Foundation (Tel: 303-794-7711) paper "Effects of Electrical Grounding on Pipe Integrity and Shock Hazard" by Steven J. Duranceau- In addition, call the Copper Development Association Tel: 800-232-3282- ask for piping group (or something like that) they have people there or under contract,who will provide the answer-

I would like to find out if all three houses had their water service installed on the same day(s) by the same plumber using the same copper pipe. Seems to me if this is the case, the finger points at a bad run of copper pipe. The pipe manufacturer should stand by their warranty. If the the copper pipe was installed at different times by different plumbers, then there is another problem. Maybe something with the soil. I have been told copper will develop pin holes if it is buried with no water flow, however, that is not the case here. Is there something in the soil attacking the copper pipe? Maybe the power company has a bad neutral. Check the current on the water pipe with a clamp on.

I have experienced the same thing. My good friend the plumber explained to me that the only time he saw trouble with copper is when someone added a circuit and ran it across his pipes. The NACE National Association of Corrosion Engineers has probably got some info on this. Its nice to know that we have something in common. Kurt Hess

Here in Ohio a similar problem came into play. As an electrical inspector I was called out since I did the original inspection. Upon arrival at the site I was shown the leaking copper water line by the plumber and the original electrical contractor was also on hand. All bonds/grounds were removed from the water line so as to get an idea on exactly what was happening. All was clean with the install so I called the electrical utility company to see what might be on their end. One thing we found out was that someone did not properly ground the transformer that was located near the front of the property but I still had reservations as that in and of it self in my opinion would not cause the copper water line to be attacked. Next call went into the soils engineer company that originally did the layout of the development. The soils engineer brought to our attention that in the plans it was recommended that they use plastic water lines since the soil contained traces of metal compounds that occur naturally in that area and can cause a dissimilar metal reaction with copper. To make a long story short they replaced the water line with plastic. Naturally the 22 other neighbors in the same subdivision demanded that their lines also be replaced. This cost the builder big bucks but it was his fault for not reading the plans.

I would start by calling a qualified electrical contractor and have them test the grounds/bonds of the system. Next contact the utility company and see if anything is wrong on their end. Keep in contact with your neighbors since they are also having problems. Hopefull someone will find the problem and also have a solution.

We were once called to a situation that reminds me of the pin hole leaks. New plumbing had been installed for a washer in the second floor of a condo. Overnight a leak developed which ruined the first floor ceiling. The plumber said the two flexible metal hoses had sort of welded together creating a leak in the union. The plumber suspected electrical current flowing through the hoses. Upon arrival we turned the disconnect off at the meter bank and began checking the wiring in the panel in the condo. I was tightening the neutrals in the panel, and everytime my screwdriver touched the edge of the cabinet while in contact with the neutral bar, a spark developed, in a panel with no power. We found a difference of about 4 volts between the neutral and the grounding bars. The caused turned out to be a slightly loose connection in the meter bank on a bolt going through four neutral busbars and the grounding busbar. Upon tightening the bolt the difference in voltage, as well as the sparking previously described, dissapeared. We never quite understood how this affected the water hoses, or if it was even related. The rest of the washers in the condo were plumbed with plastic hoses and therefore never presented a problem.

Check to see what the copper pipes were connected to at the meter or house. When copper piping is connected to galvanized pipes (or fittings) it can cause electrolysis. It has to be connected with a special brass fitting or a fitting for a plastic bushing or suitable fitting. Electrolysis in copper pipes with create small pin holes. (I usually see this around the hot water tank.

I hope this helps.

I am a real estate broker in Western NY and I have had several clients over the years with this problem. When copper is used in this application for underground service it is rarely the rigid pipe but rather the flexible tubing in 1" size. I have heard pumbers cite this as one of the factors for this problem.

I have never heard the blame put on current leaks or the pipe being used as a ground. Prevailing opininon here is bad tubing and/or acidic soil conditions.

I am curious to learn what your readers think.

From your description of this mysterious problem, my thinking centered about a few possible problem sources, none of which are easy to prove unfortunately.

The first question that came to mind is “Where did the plumbing repair contractor get the idea that the leaks could be due to “electrical current going through the copper pipes?” Can they substantiate this claim with any published or otherwise well-documented information? Is it possible that they may be basing that comment on problems they have encountered or heard about that relate to electrochemical corrosion of steel (not copper) pipes or underground tanks? I found an interesting article on Cathodic Protection (a method of protection against electrochemical corrosion) and in that article they stated that “Generally, copper piping does not require cathodic protection.“ Here is a link to that article:

http://www.cpdesigncenter.com/propanetext.pdf

The second question was, “were the houses on either side of you that experienced the same type of leaks, built by the same contractor and/or at the same time?” If so this may point to installation/workmanship issues or perhaps even a bad batch of copper piping. If your neighbors have not had their pipes fixed yet, and there is common desire to get to the bottom of this (I don’t know how expensive these repairs are), I would suggest they keep close watch on the repair and ask for the replaced piping sections…perhaps visual examination of the damaged pipes by an experienced eye will narrow down the possibilities. Also, it may be useful, during the excavation of the pipes, to inspect the areas of the pipe leaks to see their proximity to the ‘tunnel ditch’ you spoke of or perhaps other objects which may be causing mechanical abrasion.

Lastly, I found a very interesting article titled “Conditions Contributing to Underground Copper Corrosion” at the following address:

http://www.copper.org/resources/properties/protection/underground.html

I strongly suggest a strong cup or coffee (or maybe even an entire pot) and a comfortable chair for reading this one…as you will see some of the discussion gets rather technical, and they present a variety of possible causes. For the short version, here is their excellent summary:

“Copper water tubing has an outstanding history of corrosion resistance in most underground environments. Copper does not naturally corrode in most clays, chalks, loams, sands, and gravels. Certain aggressive soil conditions, however, can cause it to corrode. The basic prerequisite for corrosion is the presence of appreciable amounts of moisture. Other factors that can facilitate the corrosion process include soils having: (1) elevated concentrations of sulfate, chloride, ammonia compounds, or sulfide; (2) poor aeration, which supports anaerobic bacteria activity; (3) large amounts of organic or inorganic acid; and (4) large oxygen or neutral-salt (especially chloride) differentials.

Copper is also subject to corrosion by stray DC electricity. It can apparently be adversely affected by certain conditions in the AC system to which it might be grounded. Underground copper is reportedly susceptible to thermogalvanic effects and dissimilar material corrosion. Copper water tubes can occasionally experience corrosion fatigue.

Fortunately, in those rare instances in which copper corrodes in the underground environment, the cause of the deterioration can be identified. Once this is accomplished, corrosion can be economically mitigated by a variety of techniques.”

Depending on what evidence you are able to gather, you may discover a simple answer, or this may end up in the “cold case files”. I hope you have success!

Mike,

I believe it is worth mention to the homeowner that pinhole leaks of the speed and aggressiveness he is apparently experiencing may indicate rapid corrosion and the possible leaching of unsafe levels of copper into the water supply. Such leaching can lead to injury or illness. Before anything else, I would recommend a pH check of the water at the supply. This web site has some helpful information: http://www.plumbingsupply.com/cuinfo.html

At least one study on how/why copper pipe pitting occurs suggest factors such as pH, improperly flushed solder flux (where pitting is most often seen on the bottom of horizontal pipe), and "erosion corrosion" which occurs where undersized pipe leads to excessive flow velocity. See: http://www.wsscwater.com/copperpipe/letters/copperpipewp.cfm

An additional factor that should be tested in this situation is the free/total chlorine level, which seems suspect here since several other homes in the area are having the problem and as it has only been a few years since the pipe was installed, suggesting rapid degradation.

Regarding electrical system grounding as a contributor, a summary of various studies/research on this topic can be found here: http://www.toolbase.org/Building-Systems/Plumbing/copper-pinhole-leaks. None of the referenced research include electrical system grounding as a cause.

Best regards,

Loren Malm

From the information in the letter, I'm going to assume the homes are in a development. And that they were all built about the same time, and the water/septics were installed by the same plumbing company. Therefore I would question the quality and condition of the water pipe at time of installation and what materials were used to backfill the trench.

Limestone as well as other highly aciditic soils will corrode copper.

Another point to think about is the quality of the water. There is a development that went up around here and the acid levels were so high in the water that the water started corroding the copper pipes after 6 months. The water association would not accept fault, and many homeowners had to have their homes replumbed at their own expenses.

I too had a small pin hole leak in my copper pipe under the slab foundation. I looked up on the net to see what causes it and there is a lot of similar problems. This is one reason why it is now code to place copper above the vapor barrier instead of below it in the dirt. The pipe I had the leak in is also the one that has the plumbing ground to my panel attached to it. The panel is also grounded to two ground rods outside in mostly rocky soil. If it's not electrical current causing it then there is a lot of bad copper out there according to the web.

Your best bet is to turn to PVC. Good Luck if you ever get the contractors or city officials to help. Some soils will eat away at the copper. I bet the copper is not hard drown. (annealled).

Interesting problem. I have repaired leaking copper water lines(repeatedly) that have a deep (pipe wall deep)visible etching running randomly thru the interior of the pipe caused by electrolysis (electric decomposition). I learned from Mike's Grounding & Bonding home study class that this is caused by stray electrical current flow & can by alleviated by additional or alternate grounding means. This stray current may not be coming from your electrical system, but a neighbor or utility power transformer. Right Mike?

This website may give your member some insight into the pinhole leak problem. As a home inspector, I have run into this in recently built homes as well. The professional plumbers I have talked to about this lean toward inferior copper coming from abroad. I doubt if they have any data to back it up, however.

http://www.toolbase.org/Building-Systems/Plumbing/copper-pinhole-leaks

Some soils and groundwaters contain trace amounts of sulfuric acid that eats any kind of metal water pipe over time.

I one time changed out a well pump for a female friend and this time she decided to invest in a Grundfos stainless steel submersible pump. The groundwater 30 and 40 feet down is of good quality EXCEPT for the sulfuric acid content and in her neighborhood water heater warranties are void. When I put in the pump I made provisions for hooking up an acid neutralizer which is a tank that you periodically fill with crushed marble while the water pressure is turned off.

I rather doubt that a dissimilar metal that is in the soil and which is connected to the electrical system grounds is causing the problem because copper is near the bottom of the electromotive table. Only gold, silver, and a few other elements are more electronegative than copper. The cathodic corrosion protection current for the gas line could be finding its way into the water line but I rather doubt that.

However, gas lines should be separated 3 feet horizontally or vertically from any other utility for a number of safety reasons. Besides preventing a backhoe operator from digging through electrical and gas lines at the same time, there was an instance where a water main break underneath a street forced its way into a natural gas main in a small town and all the gas appliances had water coming out of the burners just like a slapstick comedy.

I would bet that what you have is a bad factory run of copper pipe. I one time bought some chlorinated polyvinyl chloride ( CPVC ) pipe from the closest place. Every section of pipe split when I turned on the water pressure because the extrusion parameters were somehow wrongo! I took everything down and returned the defective pipe, got my money back, and bought some pipe and fittings from somebody else. Replacement pipes and fittings worked perfectly.

Mike Cole, mc5w at earthlink dot net

I've heard of such problems, but not the electrical current having anything to do with it. I might suggest getting a sample of the ground arround the copper piping, to see if there are any minerals or corrosives that might be causing the eroding of the copper. If your home is a tract home, there might be a possibility of extra fill (dirt) that was brought in from some other area that contains these contaminents.

Some soils will eat holes in copper pipes. In a mining town in AZ I had this problem. Newer homes in the area had the copper pipes encasted in a plastic sheath to protect them from the soil problems

I hope part or all of your original copper water supply was saved and ID and have the neighbors' marked and ID as such, then go to the Local Authority having jurisdiction for quality materials installtions and make sure the copper is burial, exterior use residential pottable water supply labelled and listed for this purpose, if not, all of you need to have the original contractor do his installations correctly free of of charge, with the correct labelled and listed materials and workmanship. If you are unable to accomplish this then you know the next step. I highly recommend you also have a Kentucky certified master electrician to do a quality check of your electrical listed and labelled electrical materials and workmanship. I hope we are avoiding a domino effect

Hi Mike, I have seen this problem occur now and again in both the UK and in Australia. I would refer you to the 'Copper Develoment Association' docs on this:

************************** Alternating Current Action

The role of alternating current on the underground corrosion of copper is not well understood.9 Some investigators contend that any metal dissolved during the anodic half-cycle should be redeposited during the cathodic half-cycle. Others believe that the efficiency of the anodic half-cycle is greater than that of the cathodic half-cycle and, therefore, that AC-induced corrosion can occur. The argument persists as to whether cuprous oxide on the outer surface of an underground copper water tube can rectify AC, although some of the recent research suggests that this rectification does not occur.10, 11

Some investigators believe that a critical AC density must be exceeded for AC corrosion to occur.12, 13 It is also possible that AC facilitates depolarization of the local anodes and cathodes on an underground copper surface. 11 This depolarization would be expected to increase the corrosion-current density and the resultant corrosion rate.

Until these differences of opinion are reconciled and recent research results are corroborated, it is reasonable to believe that the commonly used practice of grounding electrical systems to underground copper water systems can lead to corrosion. If the copper plumbing system is connected to a nonconducting main, such as asbestos-cement, some corrosion damage can be anticipated where the current leaves the copper, even if the current is alternating. Further, cuprous oxide could become semiconducting under certain conditions of soil pH and electrical-field intensity. Grounding of the AC system to the underground copper water tubing and unbalance in the AC system could very well be involved in the underground corrosion process.

from: http://www.copper.org/resources/properties/protection/underground.html

We resorted to disconnecting the 'earth' to the water pipe and providing a better ground by an earth electrode. Hopefully that is working. regards Roger Royal (Australia)

My sister had the same problem on the copper connector going from the Black plastic water supply to the house and I beleive the water pipe from the street was copper. Because the problem was after the meter it cost her $500.00 for water consuption. Could it have anything to do with plastic pipe coming from the house and the water is a conductor that is seeking ground outside the connector which is at least 36" under ground? The connector actually looked like electrolysis occured like on a boat zinc. This happened about 10 years ago on a new house located in Burlington County South Jersey.

i don't know your system and yet it may help anyway.in most country in asia the supply is line to line and without earth or neutral.although this kind of grounding is permitted( water pipe as secondary ground path) however when a pipe joint has threadseal it made a high resistance to the electric current therefore resulting to high impedance ground circuit.now if your system is using one live and a neutral(earth) if you use grounding rod as a support to the earth conductor as required by some utility company(like here in asia) usually this grounding rod/plate sometimes make a high impedance and therefore poor conduction of electricity.if your neutral from utility made a loose connection or let say total disconnected for some reason your grounding rod/plate will provide the earth path and causing the current to flow (however if you didn't used grounding rod/palte as support but pipes and there lies the problem,electric current will flow to the pipes and due to reaction in long term it will ruin the pipe itself especially if this is cupper with small thickness)

this is my idea and it is posible and as matter of fact it always happen jere in asia that is why sometimes they feel electricute when touching faucet while in bare foot and on concrete floor.

Have the acidity checked to rule that out as high acidity will destroy piping.

It may be possible that there is small amout of induction on to the copper pipe through the distribution panel in the house. This is possibly causing the pipe to act as an anode such as in a cathodic protection system, Where postive voltage is injected into the ground through an anode bed system and the negitive side would be attached to the metal property being protected. If there is copper pipe in the ground in this case, most likely it is discharging small currents into the electrolysis when it should be retriving postive voltage to polarize the surface of the pipe. Suggest changing the pipe to PVC until it reaches grade or above. Most likely the water pipe should only be grounded at the water heater with a #6 AWG conductor and return path directly to earthing rod at service entrance, Not thru the distribution panel.

Have a soil sample done. It could be if there is electircal current going through the pipes it could be reacting with the soil and the copper piping. There may be some sort of disimular metal corrosion going on sped up by the A.C. going through the pipes.. From my understanding D.C. current will even speed the corrosion process more..... especially if the soil has a high alkalide content.. Then again I may just be talking out my ying-yang.... but it is something to think about....

Is it possible that the builder used the wrong class of copper tubing ? you would have to read the label I know there is a class of copper tubing that is used for drains and vents I believe it is a thinner walled pipe and would hold up to the initial pressure but would break down and leak in time just a guess good luck

First: If current flowing on copper water pipes caused them to erode and leak, then all the wire in an old house would be "worn out" and have to be replaced as it gets current flowing on it all the time. Second: Unless the insulation on the cable, telephone, power wiring is damaged, it should not matter that they are nearby. There may be accessibility reasons to separate them, but that does not seem a likely cause. And having come from a place with HARD RED CLAY and ROCKS I can understand why one ditch instead of two is attractive. Third: Those same rocks may cause physical damage to the pipe during back-fill. Or the soil conditions may be strongly acid, or basic, which is also corrosive. The water in many areas has corrosive properties. If the drips in the sink cause green stains, it is from copper dissolved by the water and left as deposits. That means the copper is eroded from inside the pipe. Fourth: Two plumbers have mentioned the possibility of "bad pipe," so that is a real possibility. The good news is that there is a faint possibility that either the plumber could be responsible for using a defective, unlisted, or second rate product and concealing the fact. Or the manufacturer may be on the hook if the pipe can be proven defective. That would likely come after you and the neighbors had repaired the water service line, and depend on the overall cost of the replacement.

Lynn Adams

It sounds like galvanic corrosion caused by dissimilar metals (the copper water line and the, probably, iron gas pipe) in contact or close proximity.

In the Washington, D.C. area, it is common knowledge that due to the water composition and the chemicals added to treat the water, there is a strong liklihood that pitting and eventual corrosion of copper plumbing will result over time. I would get the water composition checked and discuss further with your water company regarding this possibility.

I agree with Mr. Holt. The concern needs to be with any DC electrical charge on the pipes.

It would be helpful to know the age of all the homes in the area. Do the some of the homes in the area utilize pvc piping to the house?

The most likely causes of this are the already mentioned possible manufacturing problems in the pipe. The other possible cause is a soil problem. A collection of soil samples should be taken to determine if there is a corrosion problem between the soil and copper pipe. I have documented a few corrosion problems in the past for insurance companies.

If you are worried about electricity on your water piping than check your resistance on your ground rod and make sure it is the main ground system. Than your water piping is supplemental ground like it is suppose to be.

I have heard that slight electric currents present on water piping (Copper) can cause oxidization which could give this result. There is a word for it, but I can not think of the correct terminology.

If you are worried about electricity on your water piping than check your resistance on your ground rod and make sure it is the main ground system. Than your water piping is supplemental ground like it is suppose to be.

similar problem listed here. http://www.finishing.com/304/79.shtml

HERE ARE SOMETHINGS THAT WILL CAUSE PINHOLES IN COPPER PIPE. 1 HIGH RESISTANCE TO GROUND 2 UNBALLANCED LOAD 3 HIGH RESISTANCE NETURAL 4 SOIL PH 5 WRONG TYPE OF COPPER PIPE 6 HIGH MINERAL CONTENT IN WATER 7 NOT REAMING COPPER PIPE DURING INSTLATION 8 CHEMICAL CONTENT IN WATER

NO 7 IS THE MOST COMMON CAUSE OF PINHOLES.UNREAMED COPPER CAUSES EDDIES IN THE FLOWING WATER AND DOESN'T ALLOW A COATING IF MINERALS TO BUILD UP ON THE INSIDE OF THE PIPE TO PROTECT IT FROM WEAR.

NO 6 & 8 MINERALS CAN COMBINE AND STICK TO THE INSIDE OF PIPE AND CAUSE DISIMLAR METAL CROSSION

NO 4 SOIL CONDITIONS CAN EAT UP COPPER COAT PIPE WITH A PROTECTIVE LAYER OF TAR OR OTHER PROTECTIVE COATING

NO 5 USE ONLY TYPE K COPPER THAT IS MARKED FOR POTABLE WATER SOME FORIEN COPPER DOES NOT MEET ANSI STANDARDS FOR POTABLE WATER HOME DEPOT AND OTHERS SELL THIS BECAUSE IT IS LESS COSTLY

THE OTHERS CAUSE ELECTROLIS

I experienced the same problem on galv iron water pipe some fifty years ago in lake Jackson Texas. My problem was anodic action due to soil conditions. Dow Chemical Co, the principal employer in the area, was and is a major player in the cathodic protection of under ground lines. Copper is higher on the perodic table of elements than say lead, therefore, if there are lead covered lines in the area the copper would be sacrificial to the lead. Such is the case with magnesium vs iron which is the typical way of cathodically protecting under ground iron pipe lines in addition to wraping them with tar and paper. Normally iron pipes sacrifice to your typical copper clad ground rod. Hope this gives you some ideas for further investigation.

I doubt it is due to ac current as Mike mentions. However, it can still be due to electric current from galvanic action. Are there any dissimilar metals anywhere in the piping? That is do they change from copper to galvanized or black pipe? Something as simple as using a galvanized or black pipe fitting in place of a copper or brass can trigger this.

Other causes, well as mentioned the type of copper used could be at fault. Yes there are different types of copper pipe for different applications. Using the wrong type burried will result in the problem the writer is having. Something to consider since the homes appear to be of about the same age. Were they built by the same contractor and plumber? If they were trying to do the job cheaply, the cheap copper pipe will result in the problem the writter is having. Someone should be able to look at a sample of the removed pipe to determine if it was the wrong pipe or not.

Water quality can be another source of the problem. You would be surprised at how corrosive water can be. Do you know what the city is doing to treat the water? Are they doing some softening of the water? Soft water can be very agressive. This one will be difficult to figure out as trying to find and professional in this area will be expensive. The local home water softener person is not the one to contact.

Last issue the soil itself can be the source of the problem. Some soils are highly alkaline which can attack metals when burried in the soil. Unfortunately to find out on this you need a soil sample down where the pipe is burried not at the surface.

Seems that we would have seen this sort of thing in the past if it truly were a variable. Sounds like cheap pipe work.

In effect, there is current involved, but not from an improperly installed electrical system. The current is from a chemical reaction due to impurities in the pipe. The water, is the connection that allows the current to flow.

The following link explains it pretty well.

http://www.stop-pinhole-leaks.com/store/StoppingPinholes.html

Sounds like a good reason to change the plumbing code.

Mike, Pin holes in copper are a common symptom of reverse osmosis water. Water that is purified by reverse osmosis has the minerals removed and the molecules are very "hungry". The water must be buffered with chemicals to stabilize the molecules. If the buffering gets out of balance or runs out, the water will dissolve copper at a rapid rate. Plastic lines should always be used with any reverse osmosis water and some municipalities now prohibit copper for this reason.

Mike We had a similar problem with copper piping for a chiller. The pipe was mounted 10' above the ground on a rack. At first we thought it was electric current, but later found out a corrosive gas was in the air from a near by landfill. Coating the pipe solved the problem. They may want to check the soil for contaminants. One other thing to check is for a nearby gas line that may have cathodic protection. This will remove copper.

John

It has been found in Hammond Indiana that any underground copper water lines need to be wrapped in a coating material. The earth's soil was found to be deteriating the copper causing pin holes to show up in the piping. There is also the chance that if the copper piping has not been reamed out after being cut with a tubing cutter that this causes a circular affect within the pipe causing it to wear from the inside out.

This is only a guess that would require testing to confirm, but the natural gas pipe may be cathodically protected, either with buried anodes or by being connected to a rectifier system that impresses a DC voltage on the pipe. Usually gas pipes are coated with a paint that is supposed to insulate the cathodically protected pipe, but if this coating is damaged, the DC current from the cathodic protection could flow to the water pipes and cause the leaks you describe. As a precaution, I suggest you sleeve the new water pipes with a length of PVC conduit that extends well beyond the tunnel where the gas pipe is located to prevent this from happening again.

You need to contact your local water utility to see if the level of corrosion inhibitor needs adjustment. Alum is used to thicken the sediment in water before it's filtered. Some utilities add a form of phosphate for corrosion control since alum will react with copper piping.

Steel or cast iron pipes will be sacrificial to copper, so they should go first but this failure is very accelerated. This could just be contaminants in the backfill (soil near foundation). This could explain the neighbors' problem. Soil pH would be low and can be tested with soil and a little water and litmus paper from a local chemistry teacher. Not all grounds experience balanced AC and so there may be a DC component, depending on power supplies used in the home. The voltage or current could be checked with a multi-meter or sensitive clamp-on voltmeter. BE CAREFUL -if you disconnect the ground, it could go immediately to HOT if bad wiring is the problem. Realize that the voltage could also be coming from the neighbors through the pipe or from imposed voltage in soils due to cathodic protection circuits on nearby pipelines. Nice puzzle! Good luck.

Instead of assuming that electrical current is causing the deterioration of the copper water piping, the problem may simply be the choice of water pipe material.

The majority of the homes in my immediate neighborhood in Minnesota were constructed in 1986. In the last two years seven homes have experienced ruptured water service piping between the street and the house. Type L (standard) copper piping was used in 1986 instead of Type K (heavy) copper piping. Both types are acceptable by the applicable plumbing code for underground domestic water service. I have been told by the city engineer that more piping failures will likely occur in due time. If the installing contractor would have used Type K (heavy) copper piping the likelihood of a pipe rupture would be significantly minimized or the eventual pipe failure would be postponed for a much longer period of time.

While I was on the local City Council, we also had a pinhole problem with copper pipes. Some said it could have been from a change in water make up from the local water treatment plant. If water chemistry is changed, not unsafe water - just changed, the new water can cause the film that builds up inside water pipes to be eaten away leaving a pipe to deteriorate. Of course newer pipes have not had as much time to build up a film as older pipes, so new pipes are more susceptible to failure. Since water systems only guarantee safe drinking water (set by Government standards) not the exact make up, it was the home owner’s responsibility to make the repairs. My questions to your reader are this: has the water supply changed or has the local water company change the chemistry (make up) of the water.

I am aware of the fact that copper pipes will corrode if they come in contact with concrete, but A.C. will cancel out the corrosive effects due to reversal of current each cycle. I recently replaced our old steel pipes with copper, and at the urging of our town water department, I installed type 'K' semi-soft copper. It was a bit pricy, ($22.00/ft.) but the workers assured me that it will last a very long time. (They don't like to dig up & repair leaky lines, either!) We have a small current flowing through the water mains, but it does not affect K-Copper lines that have been in use for 30 years plus.

Come to think of it, The Alaskan pipe line has a negative charge on it to prevent this problem with corrosion. Makes sense to me.

My Mom & Dad had the same problem except they had pin holes underneath th floor slab in their house. The hous was only 4-years old. Does anyone know what causes this?

Get your water tested -- some places across the nation have had to go to all PVC plumbing -- due to properties of the water causing leaks and holes in copper piping.

I live in Gilbert, AZ and on my block 7 years ago we experianced a similar problem due to a factory defect from the copper pipe manufacturer. We all (6 of us) called a plumber to anylize the leakage and found it to be a factory defect. The homes were all about 6 years old at the time and we got stuck paying for the replacements as of course the "warranty" period was over.

Check the soil acid level.