Copper
What you need to know.
Source
A pipe shaped problem.
Copper is a metal frequently found within nature, however it rarely contaminates raw water at high or unsafe levels. In some cases, copper can be synthetically introduced into the local environment through means such as agricultural work or industrial pollution, consequently increasing the potential for copper contamination at the water source.
In most cases though, copper contamination in drinking water is caused by the presence of copper pipes and fittings within the water distribution system. In a process known as copper leaching, the water (typically water with higher acidity) corrodes the copper elements over time, slowly dissolving the copper into the water stream and increasing the probability of pinhole leaks appearing in the pipework.
Key indicators
Bathtub turning blue?
A key visual indicator of copper contamination (even at low levels) is blue/green staining on taps, bathroom appliances and pipes. Copper can even stain bleached hair green and create discolouration on the skin. At very high concentrations, copper can give the water itself a blue tint, while at unsafe levels it can acquire a metallic, bitter taste.
Regulatory limit
Maximum level = 2mg/l
The regulatory limit for copper in drinking water is 2 milligrams per litre (2mg/l).
This limit exists to protect against overconsumption of copper, as despite its classification as an essential nutrient, excessive copper intake can negatively impact health, particularly digestive health, with stomach pain being a key symptom of excess copper consumption.
In relation to the regulatory limit, blue/green staining can occur when copper concentrations are above 1mg/l and the bitter, metallic taste can occur when levels reach and exceed 2.5mg/l.
Testing
A metallic taste means you need to test.
As staining to sanitary wear, laundry and even hair can occur at copper concentrations below the regulatory limit, it is likely that you will be aware of the issue before it becomes a health or regulatory compliance concern.
However, if a metallic, bitter taste is present alongside staining, it is highly likely that the copper concentration has exceeded the maximum limit.
As other chemical contaminants can also cause a metallic taste, water testing is crucial to correctly diagnosing the problem.
Next steps
What to do if you suspect copper contamination.
Get to know your system
If you suspect that your water might be contaminated with copper, it’s a good idea to map out your system from source to tap in order to identify where any copper elements exist and how much is present. Usually copper pipes are the main culprit, however copper fittings, valves, alloys and coatings should not be overlooked.
Schedule a water sample
In the first instance, we would recommend discussing your concerns with your local Environmental Health Officer (EHO). Not only will they be able to schedule sampling, but they can offer guidance on risk assessments, regulatory compliance, common private water supply issues in your area, and your eligibility for government grants to help cover the costs of getting your water up to safe standards.
Alternatively, if you have questions or concerns, get in contact with us. We can advise on next steps or arrange your sampling for you.
Flush your pipes
In order to reduce the risk of excessive copper consumption, you should flush your water through your pipes before use, especially before drinking, cooking or brushing your teeth.
By opening the cold tap and letting the water run, you will be able to minimise your use of water that has had prolonged exposure to any copper within the system. The time required to fully flush your pipes will vary depending on how much copper is present in your system and where it is located, however 2 minutes is the usual recommended duration. You should flush your pipes for longer when your water has been standing in the pipes for extended durations, for example, overnight.
Do not boil your water
Copper cannot be removed by boiling your water. In fact, boiling your water to remedy the problem is both ineffective and unsafe as it will only increase the concentration of copper in your water.
Water from the hot tap may also have a higher copper concentration than water from the cold tap, as higher temperatures can increase how quickly the copper dissolves into the water stream. It is advised that water from the hot tap is not used for the purposes of drinking, cooking or brushing your teeth.
If in any doubt, we would recommend that you drink, cook and brush your teeth with bottled water while the problem is being investigated.