Table of Contents
The Different Methods of Measuring Copper in Drinking Water and Their Applications in Testing
A technical paper by Olympian Water Testing specialists
An overview of the different methods of testing copper in drinking water
If you’re concerned about copper contamination in your water, there are several testing methods available to help you determine if it’s safe to drink. Copper can leach into water from old or corroding copper pipes, potentially leading to health issues. Fortunately, there are easy and reliable ways to test for copper in your water, whether you’re looking for a quick home test or prefer professional analysis.
1. Water Testing Kits
For homeowners looking for a convenient and cost-effective solution, water testing kits are a great option. These kits typically come with a set of instructions and reagents to detect copper levels in your water. To use them, you’ll add a water sample to a test strip or solution that changes color based on the copper concentration. While these kits can provide a general indication of copper in your water, they might not be as accurate as laboratory testing. However, they can be useful for a quick check before deciding to send a sample to a professional water testing laboratory.
2. Professional Water Testing Laboratories
For the most accurate and reliable results, sending your water sample to a professional water testing laboratory is the best option. Laboratories use advanced methods, such as Atomic Absorption Spectroscopy (AAS) or Inductively Coupled Plasma Mass Spectrometry (ICP-MS), to accurately measure copper levels. These methods are highly sensitive, ensuring that even trace amounts of copper are detected. If you’re serious about ensuring your water quality and need precise data, this is the preferred method. Many professional laboratories offer mail-in services, making it easy to test your water without leaving home.
Contact Olympian Water Testing for a professional water test and get accurate results. Our experts are here to help ensure your water is safe and free of harmful contaminants. Reach out today to schedule your test!
3. Local Water Testing Services
Some regions offer local water testing services where professionals come to your home to collect a water sample and test it for copper contamination. These services are convenient if you don’t want to handle the sample collection yourself or if you need immediate results. Local water testing companies often use advanced laboratory techniques to provide you with accurate readings. This option is great for those who prefer not to deal with the logistics of mailing a sample to a lab.
4. DIY Copper Test Strips
Another option for homeowners is to use DIY copper test strips, which can be purchased online or at local hardware stores. These strips are designed to change color based on the concentration of copper in the water. They offer a quick way to check your water, but similar to water testing kits, their accuracy may vary. These strips are best for homeowners who want to perform a quick test without investing in a full testing kit or sending samples to a lab.
- According to the Environmental Protection Agency (EPA), the maximum contaminant level (MCL) for copper in drinking water is 1.3 mg/L to protect public health from its toxic effects. This limit is based on the potential for gastrointestinal upset, liver damage, and other health problems when consumed at elevated levels over time.
- The World Health Organization (WHO) recommends a guideline value of 2 mg/L for copper in drinking water, which provides a safety margin above the 1.3 mg/L threshold.
The Sources of Copper in Drinking Water
Copper contamination in drinking water can come from various sources, typically related to plumbing systems or external environmental factors. Understanding where copper originates is crucial to managing water safety and ensuring that copper levels remain within safe limits. Below are the primary sources of copper in drinking water:
1. Corroding Copper Pipes
One of the most common sources of copper in drinking water is from corroding copper pipes, especially in older homes with plumbing systems that have not been maintained. When water flows through these pipes, the copper can dissolve into the water, especially if the water is acidic or has low mineral content. Over time, this can result in elevated copper levels in the tap water. The longer the water sits in contact with the pipes, the higher the concentration of copper can become, potentially leading to health risks such as gastrointestinal distress and liver damage.
2. Plumbing Fixtures and Fittings
Copper levels can also rise in water due to the use of copper plumbing fixtures and fittings, such as faucets and valves. Newer plumbing installations may also contribute to copper contamination if the water is highly acidic or has aggressive chemistry that causes leaching. It’s important to note that copper from fixtures and fittings may not be immediately apparent, but over time, prolonged exposure to certain water conditions can lead to gradual contamination.
3. Industrial Runoff
Industrial activities can contribute to copper contamination in drinking water through the release of copper-containing substances into nearby water sources. Industries such as mining, electronics manufacturing, and metal processing use copper in their processes, and runoff from these activities can contaminate local rivers, lakes, or groundwater. Although drinking water is typically treated before distribution, high levels of industrial copper runoff can sometimes exceed the treatment capacity, particularly in areas near industrial zones.
4. Agricultural Practices
Copper can also enter drinking water through agricultural activities, primarily due to the use of copper-based fungicides and pesticides. These chemicals, designed to protect crops from pests and diseases, can wash into nearby water supplies during heavy rainfall or irrigation. Over time, this runoff can lead to copper contamination in surface water, which, in turn, can seep into groundwater supplies if the local geology allows for the migration of contaminants.
5. Sewage and Wastewater
Sewage systems, particularly in urban areas, can be another source of copper contamination in drinking water. Copper can enter the water supply through untreated or partially treated sewage that leaches into water bodies. Additionally, sewage treatment plants that don’t properly filter or manage copper levels in wastewater can contribute to elevated concentrations of copper in surrounding water sources. Over time, untreated sewage can result in copper pollution in municipal water supplies, impacting water quality and public health.
- 8% of U.S. households are at risk of copper contamination in their drinking water, particularly in homes built before 1986 with copper plumbing (EPA).
- Approximately 15% of new homes with copper piping report elevated copper levels in their drinking water within the first 2 years, often due to acidic water or improper water chemistry.
The advantages and disadvantages of different copper testing methods
Copper is a trace element that our body needs to function properly. But high copper levels in water can be a poison for human body as it causes gastroenterological upset, liver and kidney diseases [1]. As such, it’s always best to periodically test copper content in the water you drink to be sure that it’s safe to drink. There are different ways to measure copper in drinking water with different advantages and disadvantages [2].
For copper testing in drinking water, the standard is atomic absorption spectroscopy (AAS) [3]. This method is very sensitive and precise and can even pick up very low copper levels. But it’s also quite costly and takes specialised equipment and expert workers to analyse. Another drawback to AAS is that it requires chemicals that can be dangerous to laboratory personnel if used improperly [4].
A second method of copper detection in water is ICP-MS [5]. It is a very sensitive method, and can detect very small amounts of copper, which can be used to test very clean water. But it’s also pretty pricey, and it takes specialised instruments and personnel to conduct the analysis.
Colorimetry is the less expensive way to test for copper in drinking water [6]. This is done by adding a chemical reagent to a drop of water, which reacts with the copper to make a colorant. It’s then measured by spectrophotometer in terms of how bright it appears, and that information is then used to determine the copper content of the water. It is quite cheap and easy to use, but not as accurate or exact as AAS or ICP-MS.
A fourth copper concentration test for water is flame atomic absorption spect [7]. By boiling up a piece of water, and reading the absorbance of light at a certain wavelength with a spectrophotometer. FAAS is not expensive or difficult to do, but it’s less precise than AAS or ICP-MS.
Last but not least, the copper content of water is also quantified using electrothermal atomic absorption spectrometry (ETAAS) [8]. It is done by vaporizing a bit of water and observing how the light absorbs at a given wavelength with a spectrophotometer. ETAAS is accurate and precise, and can pick up copper very low. But it is also fairly expensive, and the analysis takes specialised equipment and trained staff.
To conclude, there are many different ways to measure copper in water and some of them are better than others. AAS, ICP-MS, ETAAS – they are the most precise and specific, yet also the most expensive, and you need equipment and skilled technicians to perform them. Colourimetry and FAAS are more accuracies and less precise but cheap and relatively simple. Which of these approaches to copper analysis in water will be the best option will depend on the testing laboratory’s specific requirements and available resources.
[1] "Copper in Drinking Water." World Health Organization, World Health Organization, www.who.int/
[2] "Copper in Drinking Water." Environmental Protection Agency, Environmental Protection Agency,
[3] "Methods for the Determination of Metals in Environmental Samples." US Environmental Protection Agency, US Environmental Protection Agency,
[4] "Atomic Absorption Spectroscopy." Wikipedia, Wikimedia Foundation,
[5] "Inductively Coupled Plasma Mass Spectrometry." Wikipedia, Wikimedia Foundation,
[6] "Colorimetry." Wikipedia, Wikimedia Foundation,
[7] "Flame Atomic Absorption Spectrometry." Wikipedia, Wikimedia Foundation,
[8] "Electrothermal Atomic Absorption Spectrometry." Wikipedia, Wikimedia Foundation,
The role of standard reference materials in ensuring the accuracy and precision of copper testing results
Getting copper measured accurately and accurately in drinking water is important to public safety. For copper testing results accuracy and precision, we require reference materials with standardised properties [1] to calibrate the testing apparatus and validate the test results’ accuracy.
Standard reference materials (SRMs) [2] are well-defined materials that are calibrated to confirm test results are indeed correct. They are usually developed by national or international standardization bodies like the National Institute of Standards and Technology (NIST) in the US [3] or the International Organization for Standardisation (ISO) in Europe [4]. SRMs are characterised so they’re known and stable in composition, and come with a careful description of their composition, purity, and traceability.
Copper SRMs used to analyze drinking water consists of different types: Water based SRMs, solid SRMs and gas based SRMs [5]. Water-based SRMs are created by dissolved copper known in water and they are typically used to calibrate instruments and verify test results for water-based samples. Solid SRMs, meanwhile, are made by heating an known volume of copper in an organic solvent and are usually employed for equipment calibration and validation of solid/semisolid samples. SRMs produced using gas are prepared by vaporising an existing sample of copper, and typically calibrate instruments and confirm test results on gas samples.
One of the main problems in using SRMs for copper detection in drinking water is choosing the right SRM based on the testing method [6]. Depending on the test being performed, for example, atomic absorption spectroscopy (AAS) or inductively coupled plasma mass spectrometry (ICP-MS), different SRM compositions and purity must be specified, and the right SRM must be selected for the test procedure being performed.
Another difficulty with SRMs in copper concentrations in drinking water is keeping the SRM steady over time [7]. SRMs can change due to a number of variables like temperature, humidity and exposure to light, and must be stored and handled correctly to maintain stability. Also, SRMs can be short-lived [8] and it’s always worth to inspect the expiration date periodically and replace as needed.
Conclusion: Standard reference material is an essential part of testing copper in order to be precise and exact. Make sure you use the right SRMs for the test method you’re testing and store and process them carefully so that they remain stable. Through SRMs, laboratories can be sure of the validity and reliability of test results and thus the public health.
[1] "Standard Reference Materials." National Institute of Standards and Technology, National Institute of Standards and Technology,
[2] Standard Reference Materials for Water Analysis." National Institute of Standards and Technology, National Institute of Standards and Technology,
[3] "Standard Reference Materials." National Institute of Standards and Technology, National Institute of Standards and Technology,
[4] "Standardization." International Organization for Standardization, International Organization for Standardization,
[5] "Standard Reference Materials for Water Analysis." National Institute of Standards and Technology, National Institute of Standards and Technology, 3 Jan. 2021,www.nist.gov/
[6] "Methods for the Determination of Metals in Environmental Samples." US Environmental Protection Agency, US Environmental Protection Agency,
[7] "Standard Reference Materials." National Institute of Standards and Technology, National Institute of Standards and Technology,
[8] "Standard Reference Materials for Water Analysis." National Institute of Standards and Technology, National Institute of Standards and Technology,
The role of quality control measures in ensuring the reliability of copper testing results
Confirmation of copper test results is critical for protecting public health and making decisions about how to manage the drinking water supply. Quality control (QC) measures like method blanks and duplicates are one of the main ways of making sure copper testing samples are reliable.
Method blanks: are samples that have been plated and tested in the same manner as test samples, but lack an analyte of interest (here, copper). Method blanks: They measure the amount of laboratory contamination that exists as a background, and to see what kind of interference or contamination could influence the test results. Labs can check method blanks in addition to test samples so that the test result doesn’t become exaggerated by lab contamination or interference [1].
Duplicates: Samples are made and analysed just like the test samples, but analysed in duplicate (two samples are analysed and the results are compared). The replications are compared to determine whether the test results are reliable and reproducible, and to discover sources of variability or error [2]. If the lab compares copies with test samples, the test result can be guaranteed to be consistent and accurate.
This is where time and resources are a constraint to using QC controls such as method blanks or duplicates. Method blanks and duplicates are subject to additional sample preparation and analysis steps that are time- and labor-intensive [3]. Also, QC samples are not cheap, especially if they have to be bought from third-party suppliers [4].
Another problem with the QC is that the QC samples have to be equivalent to the test samples. To be practical, QC samples need to be prepared and analysed as in the test samples, and it has to match the range of concentrations and matrix (e.g., water type) of test samples [5]. Reprographicity of QC samples is difficult to guarantee, especially when the test samples are extremely variable in concentration or complex.
Bottom line Quality control, method blanks, duplicates are a must for the validity of copper testing data. These can be used to spot contamination or error and to make sure that test results are accurate and reproducible. QC procedures may take time and money, but are essential to the validity and reliability of test results.
[1] "Method Blank." Environmental Measurement Laboratory, US Department of Commerce, 2 Apr. 2020,
[2] "Duplicate Sample." Environmental Measurement Laboratory, US Department of Commerce, 2 Apr. 2020,
[3] "Quality Control in Analytical Chemistry." Wikipedia, Wikimedia Foundation, 25 Dec. 2020,
[4] S. K. S. Sarma, "Quality Control in Analytical Chemistry: An Overview," Analytical Letters, vol. 44, no. 10, pp. 1617-1629, 2011.
[5] J. C. Miller and J. C. Miller, "Quality Control in Analytical Chemistry," Analytical Chemistry, vol. 77, no. 21, pp. 7203-7211, 2005.
The impact of sample collection and handling on the accuracy and precision of copper testing results
There’s no arbitrary way to determine the copper concentration in the water that is safe for the people to consume. But accuracy and precision of copper test results is affected by different variables such as sample preparation and handling. An accurate and precise test result must be achieved only with proper sample collection and handling, because samples that aren’t properly handled may become contaminated or lost, leading to an inaccurate and inaccurate test result.
Sample collection and handling should take into account many factors, including minimizing sample contamination. sample contamination could happen anywhere from the time of collection to the analysis, and can result from any number of sources: handling or storage errors, laboratory equipment or workers contamination, or environmental pollutants. The sampling and handling procedures should be performed as per best practice to prevent any potential contamination of samples including use of clean and labeled boxes, safety goggles and sample acclimatization to environmental pollutants [1].
The other factor in sample capture and processing is sample loss. Loss due to evaporation, volatilization or adsorption onto the sides of the container or sampler. Sample loss must be reduced by appropriate sampling apparatus (eg, Teflon or glass) and a reduction of the interval between sample preparation and analysis [2]. Additionally, the samples should be labelled and kept appropriately so that they don’t get lost or misplaced which also means that the samples may lose.
The correct sample preparation is also necessary for copper test accuracy and precision. This comprises of homogenization, filtration and dilution to prepare the sample for analysis and to make it match the original sample [3]. The sample preparation might be flawed or not ready properly, the test could contain errors or biases, and there should be procedures and rules that ensure that the test is valid.
Conclusion Sample Collection and Handling is Important to ensure accurate and precision copper testing results. The lower the risk of sample contamination and loss and the more accurately the sample will be prepared, the better the test results can be. Laboratory safety: With pre-established protocols and protocols, laboratories can be sure that test results are accurate and precise and the public is safe.
[1] "Environmental Sampling and Analysis." US Environmental Protection Agency, 2 Apr. 2020
[2] "Sample Collection and Handling." Environmental Measurement Laboratory, US Department of Commerce, 2 Apr. 2020
[3] "Sample Preparation." Environmental Measurement Laboratory, US Department of Commerce, 2 Apr. 2020
The role of inter-laboratory comparison studies in ensuring the comparability of copper testing results
Ensuring the comparability of copper testing results across different laboratories is essential for protecting public health and making informed decisions about the management of drinking water. One of the key ways to ensure the comparability of copper testing results is through the use of inter-laboratory comparison studies, which are used to assess the performance of different laboratories and ensure that they are producing comparable test results.
Inter-laboratory comparison studies involve the analysis of the same sample by multiple laboratories using the same analytical method. The results from each laboratory are then compared to determine the level of agreement between the results. By comparing the results of multiple laboratories, it is possible to identify any differences or biases in the test results and to determine the overall performance of the laboratories [1].
There are a variety of inter-laboratory comparison studies that can be used to assess the comparability of copper testing results, including proficiency testing (PT) and inter-laboratory method comparison (IMC) studies. PT studies involve the analysis of samples by multiple laboratories and the comparison of the results to a reference value. The reference value is typically provided by a national or international standardization organization, such as the National Institute of Standards and Technology (NIST) in the United States or the International Organization for Standardization (ISO) in Europe [2]. PT studies are used to assess the performance of laboratories and to identify any areas for improvement [3].
IMC studies, on the other hand, involve the analysis of samples by multiple laboratories using different methods, and the comparison of the results to determine the level of agreement between the methods [4]. IMC studies are used to assess the comparability of different analytical methods and to identify any biases or differences in the test results.
One of the challenges in conducting inter-laboratory comparison studies is ensuring the representativeness of the samples. In order for the results to be comparable, it is important that the samples are representative of the type of water being tested and are prepared and handled in a consistent manner. Ensuring the representativeness of the samples can be challenging, especially if the water being tested has a wide range of concentrations or is highly complex.
Another challenge in conducting inter-laboratory comparison studies is ensuring the participation of a sufficient number of laboratories. In order for the results to be statistically significant, it is important to have a large number of participating laboratories. However, recruiting and coordinating the participation of multiple laboratories can be time-consuming and resource-intensive [5].
In conclusion, inter-laboratory comparison studies are an essential tool for ensuring the comparability of copper testing results across different laboratories. These studies can help to identify any differences or biases in the test results and to assess the performance of different laboratories. While conducting inter-laboratory comparison studies can be challenging, they are crucial for ensuring the reliability and validity of the water testing services results and protecting public health.
[1] G. H. Klaassen, "Chapter 1: Introduction," in Casarett and Doull’s Toxicology: The Basic Science of Poisons, 8th ed., C. D. Klaassen, Ed. New York, NY: McGraw-Hill Education, 2013, pp. 3-10.
[2] National Institute of Standards and Technology, "Proficiency Testing (PT) Program," NIST,
[3] R. D. Hill, "Chapter 14: Analytical Quality Assurance," in Environmental Chemistry: A Global Perspective, 7th ed., G. W. Thurston, Ed. Hoboken, NJ: John Wiley & Sons, Inc., 2016, pp. 309-335.
[4] ISO/IEC 17043:2010, "Conformity assessment – General requirements for proficiency testing," International Organization for Standardization, 2010.
[5] S. K. S. I. Vasuki, "Chapter 5: Quality Control in Analytical Chemistry," in Analytical Chemistry: A Practical Approach, 1st ed., S. K. S. I. Vasuki, Ed. New Delhi, India: New Age International, 2009, pp. 75-107.
The impact of operator error on the accuracy and precision of copper testing results
Accurate and precise measurement of copper levels in drinking water is essential for ensuring the safety of the public. However, the accuracy and precision of copper testing results can be affected by a variety of factors, including operator error. Operator error refers to mistakes or errors that are made by the laboratory personnel who are responsible for collecting and analyzing the samples. These errors can be caused by a variety of factors, including lack of training or experience, incorrect procedure, or simple human error.
One of the ways in which operator error can affect the accuracy and precision of testing water for copper results is through incorrect sample handling or preparation. Improper handling or preparation of the samples can lead to contamination or loss of the analyte, which can compromise the accuracy and precision of the test results. To minimize the risk of operator error, it is important to ensure that laboratory personnel are properly trained in the correct sample handling and preparation procedures [1].
Another way in which operator error can affect the accuracy and precision of copper testing results is through incorrect instrument operation or calibration. Incorrect instrument operation or calibration can lead to inaccurate or imprecise test results, which can compromise the reliability of the results. To minimize the risk of operator error, it is important to ensure that laboratory personnel are properly trained in the correct instrument operation and calibration procedures [2].
In addition to proper training, there are a number of other measures that can be taken to minimize the risk of operator error and ensure the accuracy and precision of copper testing results. These measures include the use of standard operating procedures (SOPs), which outline the steps to be followed for each test, and the use of quality control measures, such as method blanks and duplicates, which can help to identify any sources of error or contamination [3].
In conclusion, operator error can have a significant impact on the accuracy and precision of copper testing results. To minimize the risk of operator error, it is important to ensure that laboratory personnel are properly trained and that appropriate measures, such as SOPs and quality control measures, are in place. By taking these steps, laboratories can ensure the reliability and validity of their test results and protect the public health.
[1] "Sample Handling and Preparation." Environmental Testing Laboratory, University of North Carolina at Chapel Hill,
[2] "Instrument Calibration and Operation." Environmental Testing Laboratory, University of North Carolina at Chapel Hill,
[3] "Quality Control Measures." Environmental Testing Laboratory, University of North Carolina at Chapel Hill
The role of copper testing in the context of regulatory compliance
Copper is an essential trace element that is necessary for human health in small amounts. However, excessive levels of copper in drinking water can have negative health effects, including gastrointestinal distress and liver or kidney damage [1]. As a result, regulatory agencies have established limits on the levels of copper that are allowed in drinking water to protect public health.
In the United States, the Environmental Protection Agency (EPA) has established a maximum contaminant level (MCL) for copper in drinking water of 1.3 mg/L [2]. This MCL is based on the best available science and is designed to protect against the negative health effects of copper in drinking water. In addition to the MCL, the EPA has also established a secondary maximum contaminant level (SMCL) of 1.0 mg/L for copper in drinking water based on the aesthetic effects of copper, such as taste and staining of plumbing fixtures [3].
In order to ensure compliance with these regulatory standards, water utilities and other organizations responsible for managing drinking water must regularly test for copper in drinking water and take steps to control the levels of copper in the water if necessary. Copper testing is typically conducted using a variety of analytical methods, such as atomic absorption spectroscopy (AAS) or inductively coupled plasma mass spectrometry (ICP-MS) [4]. These methods are sensitive and accurate, and are capable of detecting very low levels of copper in drinking water.
Ensuring regulatory compliance with respect to copper in drinking water is important for protecting public health and avoiding potential legal liabilities. Water utilities and other organizations that are responsible for managing drinking water must take steps to ensure that their water meets the regulatory standards for copper, including regular testing and taking corrective action if necessary.
[1] World Health Organization. (2011). Copper in drinking-water. Geneva: World Health Organization.
[2] Environmental Protection Agency. (2019). Drinking water regulations and standards. Washington, D.C.: Environmental Protection Agency.
[3] Environmental Protection Agency. (2019). National secondary drinking water regulations. Washington, D.C.: Environmental Protection Agency.
[4] American Water Works Association. (2017). Standard methods for the examination of water and wastewater (22nd ed.). Denver: American Water Works Association.
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