Water Pipe Corrosion Due to Grounding Problem?

Jennifer,

I have my doubts that you have a grounding problem. Your numbers with the multimeter bear this out and it wouldn't cause this type of problem anyway.

If your supply pipes ( after the plastic mains pipe ) are all copper then I would suggest that you are not seeing oxidation (corrosion of a metal eg iron , by oxygen) of the pipe. Copper pipes are used specifically because they won't oxidize. (Likewise when lead pipes were used before copper.) You might see some discolouration of the flux used around soldered joints along the pipe. Excess flux will oxidize on the outside of the pipe but the copper pipe will be fine.

Corrosion of the outside of your pipes would not imply anything about the quality of the water they were carrying unless the pipe was holed and there was some ingress of contamination into the pipe. This is possible but unlikely because the water pressure will cause leakage 'out' rather than ingress 'in'. So , my conclusion is that 'man from city water authority' he confuse issue.

It is possible to obtain simple water testing kits for specific metals. They are also fairly cheap to buy. Any chemical lab doing routine water testing would have a kit for copper. ( Or a school/ college lab, perhaps ? ) I would also consider checking with your neighbours to see if the problem is specific to youself or not.

I definitely wouldn't hire a plumber or electrican yet. They won't be able to help. The problem is almost certain to be related to the mains water supply.

Rob

I agree with you. In the past I was involved in a lot of copper pipe retrofits, and where blue and green staining was observed it was almost always due to high chlorine levels. As a side note, if this is the case, then city officials are unlikely to disclose this. Having the water chemically tested by an independent third party would be the way to go. Also, check with the neighbours, as it likely is not an isolated problem.

Cheers,

Duane

Hello Jennifer,

I would expect that you will get a lot of hits on this problem. It used to be quite common, especially in New York City high rise buildings at one time. In some cases the copper lines would deteriorate until the plumbing had to be replaced. And plumbers really hate it when electricians use the plumbing as a grounding rod.

National Electric Code requires a 10' by 1/2" copper rod to be driven into the ground for proper electrical grounding. What caused problems with the above mentioned plumbing was that several electrical distribution boxes were all tying into the same copper line which set up a series of "ground loop" circuits that conducted just enough current to carry off copper ions until the pipe was so thin that it started leaking all over the place. Very expensive to repair. Since you are seeing blue stains, it is highly likely that some copper is being leached from either copper or brass fittings and it doesn't take a lot of current to achieve that. It doesn't have to be DC either.

The easiest measurement (using the AC voltage scale first, and then try the DC scale) would be to temporarily disconnect the grounding wire and see if there is any significant voltage (greater than 2 volts) between the wire and the pipe. Some warning, however, because at this point you don't know what the voltage will be until you measure it. And a shock potential may exist if it is greater than 50 volts. The shock potential begins as soon as the contact is broken between the wire and pipe.

After you have measured the "open circuit voltage" you will need to close it by reconnecting until you can have a qualified electrician make the correction. It is entirely possible that some undetected wiring shortcut inside the house is responsible for this.

As to the health hazard, I am not a medical professional but I don't think you are in danger. Copper is one of the components in some multivitamins but it may be in a more friendly form than compound in your water. You might also want to contact the water softener company and ask them about purification testing.

Hi Jennifer:

I have read some good advice in this thread. You did not say anything about the quality of your water as delivered by the city. I would guess it is hard as you have a softener. The city is obligated to test the water for many things including heavy metals on a schedule and throughout the distribution system. If there is a problem with the city water they would be obligated to notify you. That said there can be issues with corrosive index and you should demand the city do several tests for Langlier's Index for corrosiveness. This is an established index that combines factors like dissolved solids, pH, alkalinity, calcium, and temperature. Softened water will have a much higher level of corrosiveness than unsoftened. The city should be able to provide you with the hard water levels and should be calculated over several temperatures including the coldest and hottest levels.

Once you have established the LI you can begin to take action. It would seem that you may need dielectric unions to help break the potential for galvanic cell corrosion. It occurs wherever two different metals join. Water high in mineral salts is a very good electrolite. Galvanic cell causes ions of two different metals to migrate from one side to the other. Copper will deposit on zinc for example.Hot water tanks, kitchen faucets, and other areas you see these blue deposits (copper) are potential areas for correction. You should also check lead... even if lead solder has been banned for several decades now. Lead solder is still available on the market but is restricted for use on heating systems not potable water. It may have been used and I would not take a chance with a new born expected. It should be sampled immediately after the taps have been idle for overnight (do not flush the taps before sampling) and then sampled after the tap has run for several minutes.

Last, if you have other issues like high chlorine residuals, hydrogen sulphide, or just "salty" water corrosion will be a difficult issue for you. other remedies will be suggested if these are an issue. Good Luck

Jennifer-

Had the same problem in my first house--->

No disrespect intended to most of the previous posters but your problem is not one of quantum chemistry, drip pans for grid leaks, exotic grounding malfunctions, induced NEMA code violations with stray electron fields caused by black holes or anything else exotic. You don't even need a good multimeter!

The guy from the water company, like most water company employees, is a wanabe plumber who listened intently while he was going through the company training. Problem was the water company didn't explain copper salts or anything sinilar to their employees. When the guy said the water quality was OK or good did he do any kind test in front of you? Chlorine levels differ dramatically within a water system by location, by time of day, day of the week, season of the year, and also by the source of the water.

The blue tinge is caused by the copper of the pipes reacting with free chlorine from the water. The water company probably has high levels of chlorine in the water to counteract some problem or doesn't know they have a problem. Water companies inject chlorine based on lbs of Cl2 per a volume of water and only run crude chlorine wet chemistry test to verify there injection rates.

The resultant Copper Chloride causes the blue color in the water and possibly you may detect a slight odor of chlorine in the water. At those concentrations it is not hazardous to you but I wouldn't take chances with the fetus, bottled water is a very good alternative at this time.

When I had the problem the water co. swore that quality of the water was excellent and that they had no problems. Why then did the water smell slightly like chlorine all the time and have an even stronger odor on Sundays and especially during the winter? Turns out they were cleaning there system with chlorine on sundays and because they were drawing water from a canal during the winter they were injecting more chlorine than during the summer. Finally I took my swimming pool test kit and tested the water for chlorine, a level much higher than drinking water. I registered on the swimming pool test kit. I then verified this by having some tested in a lab and the results were super high chlorine levels. The water co then fixed the problem.

This is a periodic problem in many locations. 9 out 10 times this is the problem. Try draining some water out of the bottom of your water heater tank into a white bucket. Don't be suprised if you find some bluish-green particles in it caused by the various copper chlorides.

Again, I agree that it is chlorine. In my studies I found this type of problem was typically found near the municipal water supply treatment facility or by re-chlorination centres. I have tested many buildings and the results were consistent in the buildings near the aforementioned centres.

As a note, disinfection byproducts can be toxic, carcinogenic and exposure in a shower could affect the respiratory tract, etc. If you want to know all about the dangers research (google) trihalomethanes and disinfection by-products.

Under British Standard 7671, the use of water, gas or other utility services as an earth electrode is no longer permitted; gas for obvious reasons, and gas and others because of the increasing use of non-metallic pipework in the utility supply network.

Check for Ω between the building circuit earth wiring and each utility.

Check the Wikipedia article on earthing systems. Depending upon the locality and the method of supply, it may be up to the householder to install an earth electrode under TT arrangements, particularly in rural districts where an overhead supply earth might be disconnected by a falling tree branch. If TT is required, then a 100mA residual current circuit breaker on the incoming supply is highly recommended so as to provide for the possibility of a high earth return resistance at the electrode. If not, then it is probably up to the utility supplier to install earthing, under one of either TN-C, TN-S or TN-CS arrangements.

Once these are out of the way, the rest is something to do with either a water-connected appliance or a water supply problem either in the home or upstream of it, in which case, follow the advice above.

I read many of the responses and am impressed at the wealth of knowledge available about this problem. A question to you is was your house winterized? If so flushing your water heater may be a solution if there is a possiblility of that it was filled with any winterization solution. This may be a non-issue if the water testing done thus far hasn't pointed towards this.

-just a thought.

Since you had the city test your water, I presume you are on their water system. But in case you have a well and were only asking them as an independent, it is possible that you have acidic water (pH less than 5.5). This is a common cause of "leached out" copper from pipes and is characterized by blue staining. Down here in central NC (granite country) well water is frequently acidic and a water softener system is employed to neutralize the water in the first step and then an ion exchange column is used to remove the resulting hardness. If the neutralizer part of system is not working properly, you can have soft but acidic water.

Have you had any sheetrock installled? Check to see if it came from China if so then the sheetrock is causing your trouble and will have to removed for you will get real sick. It make all metal in the house corrode and silverware also.

I wouldn't advise anyone to ingest tap water, whether from city service or private well, especially in these times, with lots of pollutant sources, but also with inexpensive under-the-sink activated charcoal filtering systems freely available. Whatever your success in correcting your problem, Jennifer, be sure to install a good quality charcoal filter and use tap water only for washing, not for eating.

Hi Jennifer,

I am sure you do not have a proper grounding. I have experienced similar problems and it would take too long to explain it here but I think I have an solutions to this problem. I suspect that due to increased Harmonic Distortion on our electrical systems today due to increased use of switch mode power supplies(in most electronics today) that we have more problems with EMF from high frequency.

Solution – you must put down two to three grounding rods in your yard at least 2-4m deep(ab.6-12feet) then attach 35mm²(ab.2 AWG) fine copper wire to the rods and connect them together and for best result measure the ground resistance - must be less than 5 ohms. Then place a copper bush bar(the bus bar is your main grounding) close to your water pipes and connect your grounding wire to it, then you must take a separate fine copper wire(3-4AWG) from that bus bar to your water pipe and other metal part of your building such as steel beams etc. + you have to connect separate wire from your power cabinet grounding to the bus bar.

Ps hope this goes well

svanbjorn@internet.is