How to Read Your Water Quality Report: Helpful Tips and Expert Advice

Today, many people are turning away from bottled water and making the move to tap water and other alternative modes. If you’ve already made the switch, it’s important to know what’s in your tap water.

The Environmental Protection Agency (EPA) requires most community water systems to notify the public once any regulated contaminants are detected and any breaches of water quality standards have occurred. This information is usually included in your annual water quality report.

A water quality report, also known as a consumer confidence report, provides information about your local drinking water quality. Essentially, it highlights what contaminants, if any, are present in your drinking water and how they may affect your health. It also includes a list of all the regulated pollutants that were detected in your water over the prior calendar year.

Although water quality reports are intended to help people make informed decisions about their drinking water, these reports can be confusing and full of complex words and expressions that are often difficult to understand.

In this guide, we will help you understand your water quality report, so you won’t go nuts trying to interpret it by yourself.

But What If I Don’t Get a Water Quality Report?

According to the EPA, if you don’t pay your own water bill, you won’t receive a report. Basically, a water quality report is not available for persons who live in apartments, condos, or rental properties, or those who get their water from private ground wells. However, if you are a tenant then you can contact your building manager or search online to see if your Community Water System (CWS) published its water quality report. You can always do a quick google search of your city + annual water quality report and go from there.

Understanding Your Water Quality Report

Summary of Water Source and Treatment Efforts

In general, every water quality report must contain information such as:

  • The sources of the drinking water, whether a lake, river, well, groundwater aquifer, or some other water sources;
  • What contaminants the municipality tests for, their treatment capacity and the standards they uphold to ensure safe and reliable water supply to your home;
  • EPA regulations and a list of all the regulated contaminants and their levels;
  • Potential health effects of any pollutant detect at a level that violates EPA’s health standards, and what you can do to prevent water-related illnesses;
  • Contact details for the water system and EPA’s Safe Water Drinking Hotline;
  • And other vital information.

Detailed Breakdown of the Contaminants Detected

Another important section of the report also is the chart breakdown of all the contaminants detected in the public water supply at the time of testing. You may also come across several codes and abbreviations that might seem technical at first. Don’t be intimated! Get familiar with the information so you can better understand what’s in your water.

Here are some of the key terms you may discover:

  • Contaminant name: The name of the substance being examined, such as sodium, fluoride, copper, lead, etc.
  • MCLG (Maximum Contaminant Level Goal): The lowest level of a particular contaminant allowed in drinking water for which there is no known or expected risk to your health. This is basically a safety boundary for each contaminated detected.
  • MCL (Maximum Contaminant Level): The highest level of a contaminant the EPA allows in your drinking water.
  • MRDL (Maximum Residual Disinfectant Level): The highest level of a disinfectant allowed in your tap water. When used in measured amounts, disinfectants can help control germs and microbes in the water. Disinfectants like chlorine are added to water to kill harmful microorganisms and make it safe to consume. The MRDLG represents the maximum level of disinfectant that should ideally be present in the water to minimize potential health risks. It is set below a level with no expected adverse health effects. 
  • Treatment Technique (TT): A required process that is undertaken to reduce the level of a contaminant in your drinking water.
  • Your Water: The maximum level of that contaminant found in your water during sampling.
  • Range detected: The levels – high and low – at which contaminants were detected in your drinking water.
  • Violation: Shows if a contaminant is present in your drinking water above the level allowed by the EPA.
  • Parts per million (ppm): One ppm represents one part of a particular contaminant per million parts of water. It is equivalent to milligrams per liter (mg/L).
  • Parts per billion (ppb): One ppb represents one part of a particular contaminant per billion parts of water. It is equivalent to micrograms per liter (µg/L).
  • Contaminant Source: the origin or the pathway through which a specific contaminant enters the water supply, such as industrial discharges, agricultural runoff, wastewater treatment plants, or natural geological formations.

The EPA has established the MCL as a protective guideline to safeguard the health of the consumers. However, many water treatment facilities try to set the MCLs within the parameters but very close to the MCLG. If the MCL goes beyond the contaminant’s MCLG, it could lead to possible side effects. If this happens, your municipality is obligated to disclose this as a violation in your water report.

Contaminants Typically Included in Water Quality Reports

    • Physical: These include contaminants you can see or feel in the water. They can be anything from tiny particles to sediment or visible materials that alter the water’s appearance or texture (Think grains of sand, fine silt, rusty fragments, debris floating around, or even small organic matter). These physical contaminants can directly impact the water’s quality and overall aesthetics.
  • Chemical: Chemical contaminants are organic and inorganic substances with a distinct chemical composition in water. They can occur naturally or find their way into water through various human activities. Chemical contaminants cover many substances, including heavy metals like lead, mercury, and arsenic, pesticides, herbicides, fertilizers, chlorine, solvents, pharmaceuticals, and industrial pollutants like PFAS.
  • Biological: As biological suggests, these contaminants are or were living organisms or the substance they produce. They typically enter drinking water through fecal matter, animal waste, or organic materials. Biological contaminants include bacteria such as E. coli, viruses like norovirus and hepatitis A, and protozoa such as Giardia and Cryptosporidium. Consuming water contaminated with these organisms can lead to potentially deadly waterborne diseases and infections.
  • Radiological: Radiological contaminants, or radionuclides, are materials with atoms inside them that give off a special energy called ionizing radiation. They do this as they break down or decay. These contaminants include radium, uranium, cesium, and plutonium. Long-term exposure to high levels of these contaminants in drinking water can increase the risk of cancer and other health problems.

Each category of contaminants—physical, chemical, biological, and radiological—can be hazardous to health. However, some within each category are more toxic than others. Keep scrolling as we delve into the most common and hazardous ones you’re likely to find in your water quality report. 

Most Common Hazardous Contaminants Listed in Water Quality Reports


Lead is one of the most dangerous heavy metals detected in drinking water. It often finds its way into drinking water through older plumbing systems and pipes, usually those containing lead or lead solder. This is a significant concern because, even at low doses, this toxic metal can have devastating health effects.

When ingested over time, lead can accumulate in the body, damaging bones, brain, kidneys, and liver. It can also cause anemia, reproductive issues, and renal impairment. Children are especially vulnerable to the harmful effects of lead poisoning. Early childhood lead exposure can lower a child’s IQ, negatively impact their behavior, and result in lifelong disabilities. 

In response, the EPA established the Lead and Copper Rule or LCR in 1991, requiring water systems to monitor the water quality at customers’ taps. If the lead concentration exceeds 15 parts per billion (ppb) or the copper concentration surpasses 1.3 parts per million (ppm) in more than 10% of customer taps sampled, water systems must take additional measures to reduce corrosion, monitor water quality parameters, and replace lead service lines. Otherwise, they must inform the public about preventive measures they can take to safeguard their health. The current action level for lead in drinking water is 15 parts per billion (ppb), but the goal is no detectable levels (MCLG of 0 ppb).

Learn more: How Lead in Water Affects Children and Adults | How to Remove Lead from Your Drinking Water


Arsenic is a naturally occurring element that can seep into groundwater from rocks and minerals. Having high levels of arsenic in drinking water poses significant health risks. Long-term exposure to arsenic has been linked to various health complications, including lung and skin cancer, decreased IQ, nervous system issues, breathing problems, and even death in high doses. The EPA has set the MCL for arsenic at 10 ppb, with an MCLG of 0 ppb. Regular testing and appropriate treatment methods, such as activated alumina or reverse osmosis, should be considered to reduce arsenic levels in affected water sources and safeguard public health.

Learn more: Effects of Arsenic in Drinking Water During Pregnancy | The Best Water Filtration System to Remove Arsenic from Water


Nitrates are essential nutrients for plants. They occur naturally in soil, groundwater, and surface water and can sneak into drinking water through agricultural fertilizers and septic systems. While nitrates aren’t usually harmful to adults, they can pose a risk to infants. Babies exposed to high nitrate levels can develop methemoglobinemia, often called “blue baby syndrome,” as it causes their skin to turn bluish. It also affects how their blood carries oxygen. The EPA has set an MCL of 10 ppm for nitrates in drinking water to keep things safe and an MCLG of 0 mg/L.

Learn more: 5 Reasons to Avoid Nitrates in Drinking Water


Nitrites are created when nitrates break down or from other nitrogen-containing sources. They’re not as common as nitrates but can still be found in groundwater and surface water. Nitrites enter our drinking water through natural processes and human activities, including septic systems and certain agricultural practices. If nitrite levels get too high, they can convert the hemoglobin in our blood into methemoglobin, causing methemoglobinemia. Symptoms of this condition include bluish skin, fatigue, dizziness, and shortness of breath. As a safety measure, the EPA has set an MCL of 1 ppm for nitrites, with an MCLG of 0.1 ppm, indicating a safe level.


Fluoride is a naturally-occurring mineral in soil, water, foods, and the human body in bones and teeth. It has proven benefits for dental health, including strengthening teeth and fighting tooth decay. Because of this, it is added to many over-the-counter dental products (like toothpaste, mouthwash, and dental supplements) and even to public drinking water supplies.

The EPA has set the MCL for fluoride at 4.0 mg/L, with an optimal level of 0.7-1.2 mg/L. While fluoride is generally safe, excessive levels can lead to dental fluorosis, which affects tooth enamel. 

Learn more: Fluoride in Drinking Water and Its Potential Effects


In drinking water, microbes, including bacteria, viruses, and parasites, are notorious for causing various potentially deadly waterborne illnesses and other adverse health problems. If you’re wondering how these tiny organisms can get into drinking water, it’s through sewage leaks, animal waste, and poor water treatment. And if you ingest them? You’ll likely develop one of many waterborne diseases, which typically carry symptoms like diarrhea, nausea, stomach cramps, and fever. In some cases, these diseases can even cause death. 

The EPA has established regulations for various microbes in drinking water, including total coliform bacteria and E. coli. To ensure microbial safety, it’s essential to regularly test water quality and implement appropriate disinfection or filtration methods, such as chlorination or UV treatment, to prevent microbial contamination and protect public health.

Learn more: The Dangers of Sewage In Drinking Water | How to Remove Coliform Bacteria from Drinking Water

What Contaminants Aren’t Listed in Water Quality Reports and Why?

Usually, water quality reports focus on the most common or regulated contaminants that concern public health. There are various reasons for this: 

Limited Testing: Water quality reports may not include contaminants that are not regularly tested for or not required by regulations. Testing for every possible contaminant can be impractical and expensive, so reports typically prioritize the most prevalent or concerning contaminants. 

Examples of contaminants with limited testing include Perfluorinated compounds (PFCs) and Pharmaceuticals and personal care products (PPCPs). PCFs are synthetic chemicals found in firefighting foam, non-stick cookware, and waterproofing materials. However, due to their specialized analysis requirements, PFCs are only sometimes included in routine water testing. Similarly, testing for the presence of PPCPs, which include prescription and over-the-counter medications and personal care products like lotions and cosmetics, is not typically conducted as a standard practice.

Secondary Contaminants: Secondary contaminants are substances that may not directly harm our health but can affect the appearance, smell, taste, or other properties of water. Unlike primary contaminants, the maximum contamination levels (MCLs) for secondary contaminants, also known as secondary maximum contamination levels (SMCLs), are not strictly enforced. Instead, SMCLs serve as guidelines to maintain water quality. Some of the most common secondary contaminants in drinking water include calcium, magnesium, and aluminum. 

Emerging Contaminants: New contaminants that have recently been identified or become a concern may not be included in water quality reports—or at least not immediately. It takes time to establish testing methods and regulations for emerging contaminants. Examples include microplastics, Per- and polyfluoroalkyl substances (PFAS), certain pharmaceuticals, personal care products, and endocrine-disrupting chemicals.

Localized Contaminants: Chances are you won’t find contaminants that are specific to certain geographical areas or sources in your water quality report. That’s because pollutants vary based on local conditions and activities and may not be universally reported. 

For instance, water quality reports may test for specific agricultural contaminants, such as pesticides and fertilizers. Still, they may not comprehensively analyze all possible agricultural runoff contaminants, such as specific herbicides or veterinary drugs. They may also include all potential pollutants associated with localized industries, such as specific heavy metals or chemical compounds, that may be present due to nearby manufacturing or industrial processes.

Individual Water Sources: Generally, water quality reports provide information on community water systems. However, if you rely on a private well or other individual water source, the specific contaminants in your water may be excluded from the public water quality reports. This is one reason private well owners are encouraged to conduct independent testing to identify contaminants that may be specific to their water source. 

What More Can I Do to Make My Drinking Water Safer?

Water treatment facilities aim to make your water safe to drink. However, if you still have doubts about the quality of your water, you can purchase a water testing kit and check for yourself or you can have it professionally tested.

In reality, some dangerous contaminants may still be present in your drinking water when it reaches your home. These contaminants can negatively affect the taste and smell of your drinking water and can be toxic to your health. Not only that. Certain contaminants can leave stains and scum in your pipes and on your fixtures and can damage your appliances over time.

Now, these situations are often difficult to deal with, especially if you attempt to apply manual labor. If you want safer and better-tasting water flowing through your pipes, you can install a whole house water filtration system to block out contaminants before they enter your home.

Water softeners also work to remove high concentrations of calcium and magnesium that make your water “hard.” Soft water prolongs the life of your appliances, makes your hair and skin softer and healthier and makes your dishes and laundry look and feel cleaner than ever before.


A water quality report can reveal important information about the quality of your drinking water. That’s why it’s crucial that you know how to interpret what it’s telling you. If the report leaves you feeling doubtful about your water quality, you can take the necessary steps above to make your water safer for you and your family.