The EPA lists copper as a contaminant. Only a small fraction is permitted in our drinking water.
It is our understanding that the maximum level of copper, according to EPA standards, is 1.3 parts per million (1.3 mg/L).
Copper tubing (in our opinion) should not be installed for water piping systems having acidic water conditions with a pH of 6.8 or less. Private wells and mountain communities can have a pH of less than 6.5. If you use copper for potable water, we recommend that you test the pH of your water.
Generally an acid neutralizer can raise the pH to acceptable levels. It is generally accepted today that copper piping and fittings can be used safely for the transportation of potable water if the water is non aggressive.
We highly recommend that you ream all copper pipes after you cut them (to lessen turbulence and potential velocity problems). We also highly recommend that you size your copper pipes correctly and when in doubt, "over" size.
Make sure the velocity of the water inside the copper piping does not travel over 8 feet per second on the cold side, nor faster than 6 feet per second on the hot side. In our humble opinion, it's best to slow down the speed of the water traveling in copper piping even slower than recommended to possibly as slow as a maximum of 4 feet per second. To do so, simply "over-size" your copper pipe sizes. It will cost more initially to "over-size" but the piping will be much quieter and also the chances for water hammer will be greatly diminished.
Think you have defective copper pipe?
The Copper Development Association is the trade association that represents all the copper tubing manufacturers. They can determine the cause of failures. You can send pipe to them for laboratory analysis.
If a manufacturing defect occurs, a claim can be made to the manufacturer by contacting Jim Weflen, Western Region Manager for Copper Development Association at: 760-944-7420. Other copper pipe manufacturer's contact information listed below:
|Residential Copper Plumbing Products Warranties Questions?
|Cambridge-Lee Industries Inc
|Cerro Copper Products
||St. Louis, MO
|Elkhart Products Corporation
|Halstead Industries, Inc.
|Howell Metals Company
||New Market, VA
|Mueller Manufacturing Entities
c/o Mueller Industries, Inc.
|Wolverine Tube, Inc.
Some say that the velocity of water inside copper pipe should not exceed the following:
Cold water systems with a flow duration of over 15 minutes = 6 feet per second or less
Hot water systems with a flow duration of over 15 minutes = 5fps or less
Hot and cold water systems with a flow duration less than 15 minutes = 8fps or less
Smallest tube sizes = 1.5 to 3fps
Hot recirculating systems = 1.5fps or less
Regarding hard water and acidity:
It is our understanding that calcium and magnesium, which creates the hardness in water, do not contribute to the corrosiveness of water. Hardness can cause many other problems but corrosiveness is not one of them. The cause of pinhole leaks in copper pipe is normally the water's pH. Below a pH of 7.0 the water is considered acidic and can eat copper pipes (the lower the pH the faster it generally can eat the copper). Also if the pH gets too far above 8.0 it can become aggressive. There are many things that contribute to corrosion - electrolysis, high temperature, extremely low dissolved solids, pH, but not hardness.
Most city water has to meet EPA's list of maximum containment levels for contaminants, pH included. Type M copper is capable of lasting a lifetime under these guidelines. If there is something eating the copper pipe from well water or another source, the problem should be fixed rather than postponing the inevitable with a thicker walled pipe. We do not believe that installing thicker pipe (i.e. going from type M to type L or to type K) is the solution to problems associated with using copper. We believe that the cause of the eating of the copper should be solved rather than allowing the copper to leach into the drinking water. If the cause cannot be fixed or determined, then possibly using an alternative-piping product should be considered.
Pinholes on only the cold side in copper piping?
Pinholes can be caused by localized corrosion cells established next to pipe wall due to excessive oxygen. If you have more leaks in the cold side compared to the hot side then possibly it is dissolved oxygen in your water. When the water is heated, the oxygen is released and vented through the pressure release on the tank. When this happens, less corrosion. The solution is to release the excess oxygen prior to entering all the plumbing.
Blue staining problems found in some water systems with copper piping is sometimes a matter of inappropriate grounding of electrical systems and the resulting electro-chemical corrosion of copper pipes. If it is, that is generally a correctable situation with a solution.
Pinholes in all of your copper piping?
A common problem is low pH or aggressive water.
Copper Pipe, Aggressive Water Linked To Illnesses
From Supply House Times, April 1998, pg 7, "NEWS" column
The ingestion of copper-contaminated drinking water resulted in numerous reports of nausea, vomiting and abdominal discomfort in two separate cases in Wisconsin. In both instances, new copper piping systems and very aggressive water combined to cause the outbreak.
Health problems associated with the ingestion of copper-contaminated drinking water are not new, said Dick Church, president of the Plumbing Manufacturer's Institute. "We've heard of situations like this before," said Church. "It's known that northern Wisconsin's water has had low pH levels and is very aggressive. As long as the plumbing products meet NSF 61 requirements, this should be a non-issue from the manufacturer's point of view."
No perfect method of piping water exists, said Catherine Bolton, director of communications for the International Copper Association. "Everything needs breaking in. Copper pipes need to build up a coating, and the time that takes depends on the water quality. Once that's set up, it deletes the possibility of leaching problems.
"Situations like those in Wisconsin are not broad-based," added Bolton. "It all depends on the water quality in a particular area. This is a water problem, not a pipe problem. Sellers need to be aware of aggressive water in their area."
An article published in the January issue of the Wisconsin Medical Journal detailed the two outbreaks and outlined the solutions implemented in both situations. In both cases "first-draw" tap water samples were collected in accordance with procedures described in the National Primary Drinking Water Regulations for Lead and Copper. Analysis of the samples found copper levels exceeding acceptable federal levels.
Once it was discovered that high copper levels caused the patients' health problems, the source of the high copper levels was determined. Aggressive water with low pH levels was being run through newly installed copper pipe. The aggressive water caused the pipe to leach copper into the drinking water supply.
Solutions to lower the copper levels in both situations were successfully implemented. The first situation involved a newly installed copper plumbing system in a trailer park. The owner had replumbed the entire trailer park. Some of the buried sections of copper pipe extended 100 ft., said Chuck Fitzgerald, drinking and ground water specialist with the Wisconsin Department of Natural Resources. The long distances made it almost impossible for people to successfully flush their systems before drinking.
"The main problem was that the owner never got the proper permission to install the system," Fitzgerald said. "If he had, we could have predicted his problem and warned him not to do what he did.
"The owner was in violation of federal copper and lead laws, so we had to take official action. We made him install a neutralizing system, which raised the pH levels to 8.5 and increased the hardness from 40 to 120 ppm."
The neutralizing system stopped the trailer park's water from being corrosive. The system wasn't cheap, Fitzgerald noted, but the $10,000 expense could have been avoided if the owner had checked with the proper authorities before beginning work.
"The contractor should have known better, too," Fitzgerald said. "He should have known about the water quality. He got a firm slap on the wrist."
The second situation centered around a condominium development. A 55-year-old woman complained to her physician of nausea, abdominal pain, diarrhea and weight loss. She also noticed her water appeared blue and left a bluish residue in her dog's bowl.
An investigation determined that her water contained a copper concentration of 2.6 mg./l., twice the federal action level. The patient's symptoms disappeared within a week after she began drinking bottled water, the Wisconsin Medical Journal reports.
In the following weeks, 251 families in the complex submitted First-draw samples. Forty-eight of the homes' copper levels exceeded federal limits. Homes built within the past 10 years had the highest levels of copper in their water supplies.
Prior to the reported health problems, the water supplier began adding phosphate to the wells in order to eliminate iron that had found its way into the water supply. An engineering firm hired to investigate the copper contamination concluded that the phosphate kept calcium and magnesium in suspension, preventing carbonates of these minerals from depositing on the inner surface of the copper pipes.
The lack of protective mineral coating caused copper pipes installed after 1991 to be more susceptible to leaching and increased the risk of copper-contaminated drinking water.
"The water supplier stopped adding phosphates to the well and the level of copper is dropping," said Mark Nelson, water supply specialist with the state natural resources department.