How to Test Water Quality At Home (Ultimate 2023 Guide)

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How To Test Water Quality At Home

The availability of clean and safe water is a necessity for everyday drinking, cooking, and cleaning. Unfortunately, the water we consume may not be as pure as we think, and it can harbor harmful contaminants that may cause severe health problems. This highlights the importance of regularly testing the quality of our water to safeguard our health and well-being.

In this article, I’ll explain why you should test your water, how to measure water quality, the different types of contaminants found in your water supply, and how to test water quality at home using a water test kit and professional testing.

Why Test Your Water?

It’s essential to be aware that the water we consume may contain harmful contaminants that can severely impact our health. Therefore, it’s necessary to regularly do water quality testing to ensure its safety. Here are some reasons why:

  1. To detect the presence of harmful contaminants. Contaminants such as lead, fluoride, chloramine, nitrates, and bacteria frequently enter the tap water supply. Drinking contaminated water can lead to severe health problems such as gastrointestinal illness, neurological disorders, and even cancer. Water quality testing is crucial, especially if you live in an area with a history of contamination.
  2. To assess the quality of the water. Using a water test kit can identify any potential problems with the tap water, treatment, or distribution systems. This information can be helpful for identifying any necessary improvements to ensure the water’s safety and quality.
  3. To comply with regulatory requirements. Public water systems are required by law to meet specific quality standards, and regular testing is necessary to ensure compliance. Private well owners are also advised to use a water test kit annually to ensure it’s safe for consumption.
  4. To address water system problems. If you notice any changes in your water’s taste, color, or odor, it’s crucial to test it to identify the problem and take appropriate measures to address it. Water testing can help identify the cause of the issue and ensure the water is safe for consumption.

When Should Water Testing Be Done?

Fluoride In Water Supply

Water testing must be done for several reasons. This can help identify any potential contaminants and ensure the tap water is safe for you and your family. Here are some instances when you should get a water sample for testing:

  1. Moving to a new home or property that has a private well or septic system
  2. After a flooding event, hurricane, or significant natural disaster
  3. Changes in the taste, color, or odor of your water
  4. Unexplained illnesses in your household.
  5. On a regular basis to ensure your tap water is safe, annually for private wells

How To Measure Water Quality

Different methods and measurement units are used to measure water quality, depending on the type of contaminants present. To better understand water quality testing at home, you need to know how contaminants are measured. When you use a water test kit, the results will be shown in these units. The following are standard measurement units used to assess water quality:

Parts Per Billion (PPB)

This unit measures the concentration of a contaminant in a billion parts of water. The ppb measurement is also equivalent to microgram/liter, so 1 ppb = 1 ug/L. It is commonly used to measure the concentration of contaminants that occur at very low levels, such as pesticides and herbicides.

For example, if a particular pesticide has a concentration of 10 ppb, it means that there are 10 parts of the pesticide in a billion parts of water.

Parts Per Million (PPM)

This unit measures the concentration of a contaminant in a million parts of water. For example, if a particular substance has a concentration of 10 ppm, it means that there are 10 parts of the substance in a million parts of water. A measurement in ppm is the equivalent of milligrams/liter, so 1 ppm = 1 mg/L.

PPM is commonly used to measure the concentration of minerals, such as calcium and magnesium, and metals, such as lead and copper.

Milligrams Per Liter (Mg/L)

This unit measures the concentration of a substance in milligrams per liter of water. It is commonly used to measure the concentration of chemicals and minerals in water.

For example, if the concentration of dissolved calcium in a water sample is 50 mg/L, there are 50 milligrams of calcium per liter of water.

Colony-forming Unit (CFU)

This unit measures the concentration of bacteria or other microorganisms in a water sample. It is commonly used to measure the level of harmful bacteria in the water supply.

For example, if a water sample has a 100 CFU/100 ml concentration, that means there are 100 colony-forming units per 100 milliliters of water.

Environmental Protection Agency Standards

The Environmental Protection Agency (EPA) is an agency of the United States federal government that sets and enforces regulations related to environmental protection, including water quality standards. These standards have been established to protect public health and ensure drinking water is safe. The EPA has set primary and secondary standards to regulate water quality.

Primary Standards

Primary standards are legally enforceable standards that limit the levels of contaminants in drinking water to protect public health. The primary standards include maximum contaminant levels for microorganisms, disinfectants, disinfection byproducts, and inorganic and organic chemicals.

The EPA sets primary standards for contaminants known or anticipated to cause health problems. Maximum contaminant levels are based on the best available science and include an adequate margin of safety.

Secondary Standards

Secondary standards are non-enforceable guidelines that limit the levels of contaminants that may cause aesthetic problems such as taste, odor, or staining of clothes and fixtures.

The EPA recommends secondary standards for water suppliers but does not require them to comply. Examples of secondary contaminants include aluminum, copper, iron, manganese, and zinc.

Which Water Contaminants Should Be Tested For?

Not all water test kits are created equal. Knowing which water test kit is best for your specific water quality is critical. Here is a list of common contaminants that can be found in city and well water sources so you know the acceptable levels and which test to use.

Biological Contaminants

Bacteria In Water

Biological contaminants, also known as microbes or microbiological contaminants, are living organisms present in the water that can cause illness when consumed. Properly maintaining water treatment and filtration systems can help protect against these contaminants. Here are some of the most common biological contaminants and the EPA limits for them:


A single-celled parasite that causes diarrheal illness and is transmitted through contaminated water or food. The EPA has set a limit of zero for Giardia in drinking water.


A parasite that causes gastrointestinal illness and is transmitted through contaminated water or food. The EPA has set a maximum contaminant level goal (MCLG) of zero for Cryptosporidium in drinking water.

E. coli

a type of bacteria that causes foodborne illnesses transmitted through contaminated food or water, with symptoms including diarrhea, abdominal cramps, and vomiting. The World Health Organization has set a limit of zero counts of E. coli bacteria per 100 ml of drinking water.


A bacteria that causes a severe respiratory illness known as Legionnaires’ disease is commonly found in water systems. The EPA has established a Maximum Contaminant Level Goal (MCLG) of zero Legionella organisms in drinking water.

Coliform bacteria

A group of natural bacteria is used as an indicator of water quality, the presence of which can indicate fecal contamination and the potential presence of harmful pathogens. The EPA has set zero total coliform bacteria limit per 100 ml of drinking water.

Chemical Contaminants

Chemical Contaminants

Chemical contaminants can enter the water through various sources, including human activities and natural processes. There are two main types of chemical contaminants: organic and inorganic.


Organic contaminants come from living organisms or their byproducts and can include chemicals such as pesticides, herbicides, and solvents. The EPA limits the levels of some organic contaminants in drinking water, including:

Volatile Organic Compounds (VOCs)

VOCs are a group of chemicals that evaporate quickly at room temperature and can be found in both natural and synthetic sources. They can be harmful to human health and the environment. Some examples of VOCs include vinyl chloride, benzene, and carbon tetrachloride.

  • Vinyl Chloride. Vinyl chloride is a highly flammable man-made chemical commonly used to create PVC plumbing and packaging materials. It is a known carcinogen with an MCL of 2 ppb in drinking water.
  • Benzene. A colorless, flammable liquid used in the production of many products, including plastics, rubber, resins, synthetic fibers, and detergents. Exposure to benzene can cause cancer, anemia, and other health problems. The EPA limits the allowable level of benzene in drinking water to 0.005 ppm (0.005 mg/l)
  • Carbon Tetrachloride. A colorless liquid that was once widely used as a solvent, refrigerant, and in fire extinguishers. However, it is now recognized as a dangerous carcinogen and is no longer produced in the United States. The EPA has set the allowable level of carbon tetrachloride in drinking water at 0 ppm (0 mg/l).
Synthetic Organic Compounds (SOCs)

SOCs are man-made chemicals found in pesticides, pharmaceuticals, and other products. Some examples of SOCs include glyphosate and atrazine.

  • Glyphosate. It is a widely used herbicide that is used to control weeds and grasses. It has been linked to a variety of health problems, including cancer and birth defects. The EPA has set the allowable level of glyphosate in drinking water at 0.7 ppm (0.7 mg/l).
  • Atrazine. It is a herbicide that is used to control weeds in corn and other crops. Exposure to atrazine has been linked to hormonal disruptions and other health problems. The EPA has set the allowable level of atrazine in drinking water at 0.003 ppm (0.003 mg/l).


Inorganic contaminants, which are mainly comprised of heavy metals, do not contain carbon atoms and may include substances like lead, arsenic, and fluoride. The EPA has established limits for the levels of some inorganic contaminants in drinking water, which are as follows:


Iron levels in drinking water should be less than 0.3 ppm (0.3 mg/L). High levels of iron can cause discoloration and a metallic taste in the water.


The EPA has set a limit of less than 0.05 ppm (0.05 mg/L) for manganese levels in drinking water. High levels of manganese can cause discoloration and an unpleasant taste in the water.


Arsenic levels in drinking water should be at 0 ppm (0 mg/L). Arsenic is a toxic substance that can cause cancer and other health risks.


The EPA has set a limit of less than 1.3 ppm (1.3 mg/L) for copper levels in drinking water. High levels of copper can cause gastrointestinal problems and liver or kidney damage.


Lead levels in drinking water should be at 0 ppm (0 mg/L). Lead can cause developmental delays, behavioral problems, and other health issues, particularly in young children.


Mercury levels in drinking water should be less than 0.002 ppm (0.002 mg/L). High levels of mercury can cause neurological damage and other health problems.


The EPA limit for fluoride levels in drinking water is less than 2 ppm (2 mg/L). Fluoride can help prevent tooth decay, but excessive levels can cause dental fluorosis and other health problems.


The EPA has set a limit of less than 10 ppm (10 mg/L) for nitrate levels in drinking water. High levels of nitrates can cause methemoglobinemia, a blood disorder that can be especially dangerous for infants.


The EPA limit for nitrite levels in drinking water is less than 1 ppm (1 mg/L). High levels of nitrites can cause methemoglobinemia, a blood disorder that can be especially dangerous for infants.


Water Disinfectant

Disinfectants are added to the municipal water supply to kill microorganisms and bacteria.


Chlorine is the primary disinfectant used by public water systems to treat unwanted microbes. The current EPA enforceable limit on chlorine in drinking water is 4 ppm. Many municipal water suppliers have switched to chloramine to meet the disinfection byproduct standards. Chlorine can also be used as a private well disinfectant solution.


Chloramine is a chlorine and ammonia mixture added to water supplies to control microbes.

Disinfection Byproducts (DBP) & Total Trihalomethanes (TTHM)

Disinfection byproducts occur when disinfectants react with organic material in the water supply. The EPA set enforceable limits on several total trihalomethanes and haloacetic acids (HAA), including chloroform, bromodichloromethane, and trichloroacetic acid.


Radionuclides are a group of contaminants including radon, uranium, alpha, and beta particles. The EPA has a maximum contaminant level goal of zero mg/L in drinking water. Radionuclides generally come from the natural erosion of deposits in the earth and can lead to an increased risk of cancer and kidney toxicity. Testing for uranium and radon requires specialized testing kits.

Physical Contaminants

Home Water Contaminants

Physical contaminants in water refer to any materials or substances that can be seen, felt, or tasted, including suspended particles, sediments, organic matter, and inorganic matter. The presence of physical contaminants in water can affect its clarity, taste, and odor and may pose health risks to humans and aquatic life.

The Environmental Protection Agency (EPA) has established limits or standards for physical contaminants in private water systems under the Safe Drinking Water Act (SDWA). These standards set the maximum allowable levels of physical contaminants in public water systems to ensure the water is safe for consumption. Some of the physical contaminants and their EPA limits include:


Turbidity is a measure of the cloudiness or haziness of water caused by the presence of suspended particles. The EPA has set a maximum contaminant level (MCL) of 0.3 NTU (nephelometric turbidity units) for public water systems.

Total Dissolved Solids (TDS)

Total dissolved solids (TDS) are a measure of the total concentration of dissolved inorganic and organic substances in water. It includes minerals, salts, and other substances that can affect the taste and appearance of water. The EPA has set a secondary maximum contaminant level (SMCL) of 500 milligrams per liter (mg/L) for TDS in public water systems to ensure that the water is aesthetically pleasing and does not have a noticeable taste or odor.

Total suspended solids (TSS)

TSS refers to the amount of suspended particles in water, such as sediment, organic matter, and inorganic matter. The EPA has set an MCL of 500 mg/L for TSS in public water systems.


Color in water is usually caused by the presence of organic matter or other contaminants. The EPA has set a non-enforceable secondary standard for color in public water systems, with a recommended limit of 15 color units. For example, tannins are a common issue with well water where the color turns a brownish-yellow color. Iron and manganese are also notorious for causing discoloration.

Potential Hydrogen (pH Level).

pH levels refer to the acidity or alkalinity of water. The EPA has set a secondary maximum contaminant level (SMCL) of 6.5 to 8.5 for pH in public water systems to ensure that water is not corrosive to copper or lead pipes and does not contain harmful levels of metals. The pH levels scale ranges from 0 to 14, with 7 being neutral. Water with a pH lower than 7 is acidic, and water with a pH higher than 7 is alkaline.

Water Hardness

Water Hardness

Water hardness refers to the concentration of dissolved minerals in water, mainly calcium and magnesium. Hard water is generally safe to drink but can cause scaling in pipes, plumbing fixtures, and appliances, decrease the effectiveness of cleaning products, and affect the taste of food and beverages. The EPA has not set any regulatory standards for water hardness.

Home Test Collection Precautions

When collecting a water sample for testing, it’s essential to take the necessary precautions to ensure the sample comes back with accurate results. Water samples can be contaminated which may lead to false positives. Here are steps to follow for accurate results with your test samples:

  1. Use a clean, sterile container provided in the test kits to collect the sample.
  2. Collect the sample from tap water that’s been running for at least two minutes.
  3. Don’t touch the inside of the container or the tap with your hands.
  4. Fill the container to the required level without splashing or overflowing.
  5. Keep the container sealed until you’re ready to test the sample.

Laboratory Water Test Kit

Tests for dozens of well water and city water contaminants
Analyzed in a certified laboratory
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How to Test Water Quality at Home

Doing water quality testing at home is an essential step to ensuring the safety and health of your household. There are different methods available, and each has its own advantages and disadvantages. The two most common ways are using certified lab testing or an at-home water quality test kit.

Certified Lab Testing Kit

Certified lab testing kits are the most accurate and extensive testing method for water quality. They are the best option for the analysis of water quality and can detect the exact concentration of various contaminants.

1. Collect A Water Sample

The first step is to collect a sample of the water you want to test in the provided collection bottles. Follow the specific instructions provided with the testing kit to ensure the sample is collected correctly.

2. Prepare The Sample For Shipping

Once the water sample is collected, it needs to be properly prepared for transport to the lab. This may involve adding preservatives or storing the sample in a specific type of container.

3. Send The Sample To The Lab

The next step is to send the sample to the lab for analysis. The lab will typically provide a pre-addressed and pre-paid shipping label to make this process as easy as possible.

4. Wait For The Test Results

After the lab receives the sample, it will take a few days to process and analyze the sample. The lab will then provide a detailed report of the water quality results, including information on any contaminants that were detected and at what levels.

5. Interpret The Results

Once you receive the results, it’s important to interpret them correctly. If any contaminants were detected, the report will provide guidance on what steps to take to treat the issue. If the results indicate the water is safe, you can rest assured you’re drinking clean, high-quality water.

DIY At-Home Water Testing Kits

At-home tests are water testing kits designed to allow homeowners to test their water quality without sending a sample to a laboratory. This type of home testing kit will typically come with simple instructions and all the necessary materials to conduct tests for specific contaminants. The at-home water quality test kits can be purchased online or in stores and are generally more affordable than certified lab testing.

  • Affordable and readily available in stores or online
  • Easy to use with simple instructions
  • Can provide a quick snapshot of water quality.
  • Can test for specific contaminants, such as lead or chlorine.
  • Less accurate than lab tests.
  • User error can affect results, including improper use or interpretation of results.
  • Limited range of contaminants that can be tested.
  • It may not detect low levels of common contaminants that can still pose health risks.

Water Quality Test Strips

Chlorine Test Strips

Water quality test strips are a convenient and affordable way to test for a range of contaminants in your water supply. These test strips are simple to use and can provide results within minutes, making them an excellent option for quick and easy water testing. Here are the steps involved in using a water quality test strip:

  1. Collect a cold water sample in a clean container.
  2. Dip the test strip into the water for a few seconds.
  3. Remove the strip and shake off any excess water.
  4. Wait for the recommended time (usually a few minutes) for the strip to change color.
  5. Compare the color of the strip to the chart provided to determine the level of contaminants in your water supply.

The colors on the test strips can be compared to a color chart that will reveal the level of contamination in milligrams per liter (mg/L) or parts per million (ppm). The color chart will typically include a range of colors that correspond to different levels of contamination, allowing you to easily determine if the water supply is safe for consumption or if further testing is needed.

Bacteria Testing Kit

Home Water Test For Bacteria

Bacteria testing kits are designed to test for the presence of harmful bacteria in your water supply, such as E. coli and coliform bacteria. These kits test typically come with test tubes and reagents that react with bacteria to produce a color change or other visible result. Here’s how to generally use a bacteria testing kit:
Collect a water sample in a sterile container provided in the home test kit.

  1. As per the instructions, add a specified amount of nutrient broth or solution to the container.
  2. Mix the solution well and incubate it at a specified temperature for a specified amount of time.
  3. Check the sample for the presence of bacteria by looking for the presence of growth or a change in the color of the broth or solution.
  4. Compare the results with the instructions provided in the kit to determine if harmful bacteria such as E. coli or coliform bacteria are present in the water supply.

Additional Factors to Consider

Additional factors should be considered when testing water quality at home beyond the testing methods and frequency. These factors can impact the test results and the steps you should take to address water quality issues. Here are some of the most important factors to keep in mind

Water Source

The source of your water can affect its quality, and different contaminants may be present depending on whether your water comes from a well or a municipal source.

If you have well water, you may need to test more frequently for certain contaminants, such as bacteria or nitrates.

If you have municipal water, you can check with your local water utility for their most recent water quality report or Consumer Confidence Report (CCR). If you choose to get your own test, make sure it is a city water test kit.

Testing Frequency

The frequency of water testing depends on a few factors, including the type of water source, the presence of contaminants, and any potential changes in the water source.

Experts recommend testing well water at least once a year and municipal water at least once every three years. However, you may need to test more frequently if there are changes in your water source or if you suspect contamination.

Regulatory Guidance

Regulatory guidelines for water quality testing include the Safe Drinking Water Act and the Clean Water Act. These guidelines set standards for acceptable levels of contaminants in drinking water.

It’s important to check these guidelines when interpreting water quality test results and determining the appropriate action. Sometimes, you may need to report water quality issues to your local health department or take steps to address the issue, such as installing a treatment system.

Frequently Asked Questions

How do you know if water is safe to drink at home?

The only way to know if your tap water is safe to drink is to test your home’s water. You can conduct a test using DIY home test kits, or if you want more accurate results, a laboratory test kit.

What is the best DIY home water quality test kit?

The best home water test is to use a certified lab test kit. These kits will analyze dozens of contaminants and provide the specific amount detected in your water. Other DIY kits are useful for spot-checking certain contaminants like chlorine or bacteria but are less accurate and prone to errors.

Are home water testers accurate?

Yes, using a certified lab testing kit is extremely accurate. Other test methods like testing strips or color-changing drops are less accurate and do not provide the specific concentration of the contaminant.

How to test water quality at home without a kit?

You can check the EPA Water Quality Reports that are required by municipal water suppliers to test the water quality once per year. These reports will break down any contaminants found in your water supply system. There are also certain contaminants that can be tested in a DIY manner like water hardness, or pH levels. However, most contaminants require specialized testing to analyze.

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