Some professional sources estimate that copper corrosion cost United States residents more than $1 billion every year. Many homes are affected by copper corrosion, and there are many possible causes. This can lead to pipe failure accompanied by the telltale blue stains or tubs, sinks and fixtures, caused by oxidized copper. In this article, we will take a closer look at copper corrosion, examine how it’s caused and offer some solutions.
What is Copper Corrosion?
The official definition of corrosion is “the deterioration of a substance or its properties due to a reaction with its environment.” Essentially, the metal (in this case copper) pipes are dissolved away into the water that passes through them. There are a number of possible causes, but they all end with a pipe failure and corrosion in your water using appliances, such as washing machines, dishwashers, and water heaters. Plumbing fixtures will also be affected because of this physical and chemical reaction that happens between the copper pipes and the water passing through it.
What are the Causes of Copper Corrosion?
There are nine common causes of copper corrosion in domestic plumbing; they are listed below in no particular order.
Alkaline water with a pH level of 8.5 or greater.
Acidic water with a pH level of 7.0 or less.
Excessive levels of dissolved oxygen.
Bacteria that causes corrosion, such as iron bacteria or sulfates.
Elevated level of dissolved salts in the water (also known as total dissolved solids or TDS).
High water velocity in relation to the plumbing pipe sizes that causes hydraulic wear and tear on the pipes.
Hydraulic wear caused by grit, sediment, and sand in the water.
Electrochemical issues, such as lightning strikes on nearby utility poles with grounding wires and/or electrical appliances in the home that are not grounded.
Shoddy copper pipe installation that has left burrs on pipe ends and/or excessive flux has been used to solder the pipes.
What are the Effects of Copper Corrosion
The effects of copper corrosion range from the annoying up to expensive and even dangerous. One of the first things that many people notice is that their laundry is covered with blue tinting and stains. These stains may also be seen in tubs, sinks, and showers and they can be hard to scrub away.
Over time the copper corrosion will only get worse, and the plumbing pipes will begin to fail. At first, this may be a tiny leak and then gradually cracks will appear throughout the plumbing system. This will result in water damage that you may not notice for some time and this will be expensive to fix.
Finally, drinking water with a copper content of over 1.0mg/L should not be used for drinking and cooking as it’s considered to be toxic. Copper toxicity is also known as copperiedus, and it can be responsible for a variety of health conditions, such as hypotension (low blood pressure), gastrointestinal distress, jaundice, melena, vomiting, hematemesis (vomiting blood), kidney damage, liver damage, and even psychological and/or neurological problems. These health issues typically manifest when copper is ingested at extremely elevated levels over a prolonged period.
Can Copper Corrosion be Stopped?
The short answer is yes, but some preparatory work will need to be done first, and a professional plumber will be required. Below, we will look at some steps that you can take to identify and prevent copper corrosion in your home.
Identify the severity of the problem and the source of the copper corrosion. This can be achieved with a professional inspection of your plumbing system and by carrying out a water analysis test. It’s especially important to test your water if you’re using well water.
Find out if there is any unnecessary electrical wiring or appliances that are connected to your plumbing pipes. The pipes need to be grounded to an earth ground to ensure that there is electrical continuity throughout your plumbing system. As an example: any copper piping shouldn’t be separated by sections made from other materials, such as plastic pipe sections, PVC water filters, and bypass valves. If these parts are present, a jumper cable should be connected to the copper piping before and after them.
Check the pH level of your water supply to establish its characteristics, such as acidity, alkalinity, temperature, hardness and the levels of TDS.
Carry out a Langelier Saturation Index (LSI) calculation to determine whether your water supply is aggressive or corrosive.
Remove some small section of your copper piping, cut them in half lengthways and inspect it for corrosion and damage. Then replace the copper piping as required to maintain a water connection.
Consider installing a soda ash feeder or a calcite neutralizer tank to correct for a low pH level by raising it to 8.0 or 7.2 respectively.
Use a phosphate feeder, install it before the start of your copper piping and the phosphate will reduce the corrosion. The phosphate is food grade, it will coat the internal surfaces of the copper pipes, and over time an insulation surface will build up.
If you have a high TDS at a level of over 1,000ppm, install a whole house reverse osmosis (RO) system and follow up with a calcite neutralizer.
If your water supply has iron bacteria and/or “rotten egg” sulfur odors install a chlorinator to disinfect the water.
If you receive your water from a municipal utility make sure to call them and report that you have a problem. Your water issues could be an isolated problem, and one of the causes listed earlier is the cause.
There are many steps that a
plumbing professional can take to help you combat a copper pipe corrosion problem. Some simple adjustments may be needed to lower water velocity, and temperature or additional measures may be necessary to make the water less corrosive. Any corroded pipes will need to be replaced, and it’s a good idea to make a switch to a non copper alternative, such as; stainless steel or PEX, to prevent a recurrence later on.
By Giovanni Longo President Flood Brothers Plumbing
Giovanni Longo is a 3rd generation master plumber who has been practicing his craft and trade in the greater Los Angeles area for well over a decade and a half. A plumbing and hydraulics-engineering innovator, Giovanni’s particular world-class expertise focuses on dealing with challenging sewer system designs as well as resolving complex commercial and residential draining issues. As a certified Flood Mitigation expert, he is also well versed in a wide variety of water damage and remediation solution.
