Frequently asked questions
Health and drinking water
Water filters and water quality
- My water has contaminants detected above health guidelines. What does this mean? Do I need to use a filter?
- What kind of water filter should I buy?
- I’ve checked the database to see which chemicals were detected in my tap water and purchased an appropriate water filter. What else can I do to make my water better?
My water system
- Your database does not have any information about my water system. Where can I find this information?
- Where does my tap water come from?
- How does EWG’s Tap Water Database compare to my local water utility’s Consumer Confidence Report?
Drinking water contaminants
- Are some people more sensitive to water contaminants than others?
- Should I be concerned about lead in my tap water?
- My tap water has a strange smell, taste or color. Should I be concerned?
- My water smells like chlorine. What should I do?
- Where can I get my water tested?
- My community has issued a “boil water” alert. What does that mean?
The Tap Water Database
- What is the purpose of EWG’s National Tap Water Database?
- Where did the data in your database come from?
- Does the EPA have a similar database available online?
Health and drinking water
Is my tap water safe to drink?
Most community water systems get a passing grade from the federal government, because drinking water regulations allow contaminants in tap water at levels greater than what scientists deem to be safe. In addition, there are many unregulated contaminants that end up in drinking water.
If you want or need better drinking water than what comes from the tap, EWG suggests buying a home water filter certified to remove or reduce the contaminants found in your tap water. EWG has developed an extensive online guide to choosing a water filter, which will help you decide which one is right for you.
Is bottled water safer than tap water?
In most situations, bottled water is not the answer. The problem with bottled water is that you cannot be sure what you are getting. Reports show that some bottled water is just tap water, filtered in some cases and untreated in others. Unlike public water suppliers, bottled water manufacturers are not required by law to disclose the levels of any contaminants in their products.
In addition to water contaminants that could come from the source water, bottled water may also be contaminated with plastic additives that can migrate from plastic packaging. Many of these additives have not been fully assessed for safety by the Food and Drug Administration, the agency that oversees food and beverage packaging.
Bottled water may be the appropriate choice in an emergency – after major storms or earthquakes, or a large-scale infrastructure failure. In cases such as these, choose bottled water that carries a disclosure about its source and treatment, and the results of water quality testing.
Water filters and water quality
My water has contaminants detected above health guidelines. What does this mean? Do I need to use a filter?
Health guidelines are defined by scientists as the amount of a contaminant in drinking water that is not expected to pose any health risk. Tap water contaminants are not good for anyone, and they are especially a concern for vulnerable populations and during sensitive periods of development, such as pregnancy and early childhood. Even for healthy adults, water filtration is beneficial.
Certain contaminants can be removed only with advanced water filtration systems, but a simple countertop carbon filter is a great option for removing many types of contaminants.
What kind of water filter should I buy?
EWG has developed an extensive online guide for choosing a water filter that meets your needs. The guide can help you choose a filter on the basis of total cost, removal of specific contaminants, scale of water filtration or filter type.
I’ve checked the database to see which chemicals were detected in my tap water and purchased an appropriate water filter. What else can I do to make my water better?
One of the best things you can do to make your water better is to hold elected officials accountable. EWG has developed a list of questions you may use when you contact those with influence over your water quality – from your city council all the way to the Oval Office.
Make sure to urge leaders to invest in better water treatment technology, create sustainable funding for water system improvements, and protect source waters to keep pollution out of your water in the first place.
My water system
Your database does not have any information about my water system. Where can I find this information?
Although the database is very extensive, EWG was not able to obtain data for every water utility in every state. If you seek water quality information for a system that is not in the database, contact that water utility directly.
Start by requesting the annual Consumer Confidence Report to look at your system’s compliance with federal drinking water standards. The largest utilities are required to post their CCRs online; other systems will provide a copy upon request.
The annual reports tell only a part of the story. For more information, compare the levels detected by your utility to the EWG-identified health guidelines.
Where does my tap water come from?
Drinking water sources vary considerably across the country and even within communities. Water utilities may depend on surface water, including streams, rivers and lakes; or they may pump groundwater out of wells. They may use multiple sources that vary seasonally. In addition, many systems buy water from other companies or large-scale suppliers. For more information on where your tap water comes from, contact your local water utility.
How does EWG’s Tap Water Database compare to my local water utility’s Consumer Confidence Report?
The water quality reports that utilities are required to give their customers show only a partial picture of what people are actually drinking. These reports contain average levels and ranges detected for most contaminants, but they do not show spikes in contaminant levels that may have occurred during the year.
The reports typically contain information on federally regulated contaminants only, because water utilities are not required to include any additional monitoring data they might have collected. The Environmental Protection Agency requires only that utilities report regulated and unregulated chemicals that are included in special testing programs.
Most importantly, the annual utility reports do not list health guidelines or say whether some contaminants were found at levels that, though legal, may not be safe. Water utilities are only required to list violations of legal limits, which are often much higher than the health guidelines.
Consumer Confidence Reports compaired to EWG’s Tap Water Database
|Consumer Confidence Reports||EWG’s Tap Water Database|
|Testing details||Typically show yearly averages for contaminants detected and do not mention seasonal spikes in pollution.||Gives a precise picture of water quality throughout the year, listing full test results for each pollutant.|
|Safety levels||Compare pollution to regulatory limits, which are often based on political and economic compromise and do not fully protect public health.||Focuses solely on health, comparing pollutants to levels scientists say are safe for everyone, including babies and pregnant women.|
|Number of contaminants||Typically show the detections of federally regulated contaminants, yet more than half of the contaminants present in tap water have no regulatory limit.||Shows all test results for all monitored contaminants, not just those with legal limits.|
|How your water compares||Does not show how your water quality compares to that of other communities across the state and country.||Compares test results for all pollutants to state and national averages.|
Drinking water contaminants
Are some people more sensitive to water contaminants than others?
Yes. People with severely compromised immune systems, such as people with cancer who are undergoing chemotherapy, people with organ transplants, people with HIV/AIDS or other immune system disorders, some elderly people, and infants can be particularly at risk.
People in this category should take special precautions with the water they drink and seek advice from their health care providers about drinking water.
The EPA, together with the Centers for Disease Control and Prevention, publishes recommendations to help people with compromised immune systems take extra precautions when it comes to their drinking water.
Should I be concerned about lead in my tap water?
First, ask your water provider whether tap water enters your home through a lead service line. Even if the pipes leading toward the house are not lead-based, there might be lead in the household plumbing fixtures, so consider getting your tap water tested for lead.
Testing is particularly important if you live in an area served by lead-based water lines; if your local water company has detected lead in your neighborhood; or if you are a private well owner and lead has been detected in well water in your area.
If there is lead in your water, you can reduce it by flushing pipes with cold water each morning, using only cold water for cooking, and installing a home water filter. But these are just temporary solutions. The only permanent fix to chronic lead contamination is to replace lead-based water pipes.
For more information about lead in drinking water and tips to decrease your family’s exposure, read the “What About Lead?” section in the Tap Water Database.
My tap water has a strange smell, taste or color. Should I be concerned?
Unpleasant smells, colors and tastes do not necessarily mean your water is unsafe to drink. But these can be important indicators of potential safety problems. EWG recommends that you contact your local water supplier to investigate these conditions.
If the smell, color or taste is related to excessive minerals in your water, a home water filter can help solve the issue. EWG has developed an extensive online guide to help you choose a filter that might help solve your problem.
Another source of an unusual water smell could be the growth of algae in the source water used by the water utility. Algae toxins cannot be removed by ordinary water filtration methods. If your water utility reports algae contamination, you may need to use bottled water temporarily.
My water smells like chlorine. What should I do?
Each water system determines its own practices for chlorine disinfection. Especially after big rainstorms – when large amounts of plant and animal waste, sewer discharge and urban runoff can end up in the water – your water system may add more chlorine or other disinfectants to combat the influx of disease-causing microorganisms.
Although essential to protect public health from waterborne diseases, these disinfectants also leave behind carcinogenic disinfection byproducts. To deal with excess chlorine and disinfection byproducts, you may want to install a home water filter designed to remove these chemicals from drinking water. EWG has developed an extensive online guide to help you find the right one.
Where can I get my water tested?
Many labs around the country test water for common contaminants. We recommend that you choose one that has been certified by the state to test drinking water. The EPA’s website has additional information and resources to help you choose an appropriate lab.
My community has issued a “boil water” alert. What does that mean?
If a water system has issued a boil water alert, it is likely that one or more microbiological contaminants were discovered at levels exceeding those allowed by the EPA. The water system must then take appropriate corrective action, continue to monitor its water supply and notify customers when it has remedied the problem. Until then, make sure to follow guidance issued by your water system.
Under the provisions of the Safe Drinking Water Act, water systems that serve more than 25 people are required to test their water regularly for a wide variety of contaminants, including microorganisms.
The Tap Water Database
What is the purpose of EWG’s national Tap Water Database?
EWG developed the national Tap Water Database because we believe everyone has the right to know what’s in their tap water. Although the government requires utilities to make some information public, utility reports often don’t tell the full story.
EWG’s database is currently the only free online consumer resource that analyzes tap water quality purely with respect to human health. Users can search by ZIP code to find their water utility, see the detected contaminants in their water, and learn how the levels of contaminants in their water compare to state and national averages and health guidelines.
Through user-friendly displays, EWG’s database educates consumers about chemicals detected in their tap water, highlighting whether these chemicals were found above levels that scientists deem safe and describing the associated health effects. The database also makes it easier for consumers to avoid many of these contaminants by helping them find filtration devices and systems that have been certified to remove specific contaminants.
Where did the data in your database come from?
EWG requested water contaminant data from public and environmental health agencies in all 50 states and the District of Columbia. We then compiled the over 31 million records we received. The database also includes water quality data collected as part of the EPA’s Unregulated Contaminants Monitoring Rule.
EWG released the first version of the database in 2005 and updated it in 2009, 2017, 2019 and 2021.
Does the EPA have a similar database available online?
No, but it should. In fact, the 1996 Safe Drinking Water Act Amendments require the EPA to produce such a public service, stating: “Not later than 3 years after the date of enactment of the Safe Drinking Water Act Amendments of 1996, the Administrator shall assemble and maintain a national drinking water contaminant occurrence data base, using information on the occurrence of both regulated and unregulated contaminants in public water systems.”
More than 20 years later, the EPA still has not made this data public in a readily accessible or easy to understand manner. Until the federal government steps up to protect Americans from drinking water pollution, EWG’s Tap Water Database will continue to fill this important gap.