Even if your tap water looks crystal clear, it’s probably hiding a host of invisible contaminants — and the Environmental Working Group (EWG) has the data to prove it. Over 143 million people around the world are exposed to PFAS in their drinking water daily1.
To help reveal the omnipresence of these contaminants, the EWG just launched the newest edition of its Tap Water Database, which aggregates data on 50,000 water systems across the country from 2021 to 2023. This is the latest update of the EWG tap water database, which first began in 2005.
What Is the EWG Tap Water Database For?
The EWG water database reveals the widespread presence of chemicals, heavy metals, and other worrying substances in drinking water across the U.S. — only some of which are regulated by the Environmental Protection Agency (EPA).
“In short: Legal does not mean safe,” writes EWG. “Most community water systems get a passing grade from the federal government, even though contamination may be higher than what the latest science shows is safe. That’s because many drinking water regulations are out of date or based on outdated science. And there aren’t any regulations for many contaminants.” In other words, most of us are drinking contaminated water without realizing it.
While EPA is legally required to publish this data based on the 1996 Safe Drinking Water Act Amendments, its failure to do so nearly 30 years later has inspired EWG’s continued work in this arena2. The EPA “still has not made this data public in a readily accessible or easy to understand manner,” EWG writes3. “Until the federal government steps up, EWG’s Tap Water Database will continue to fill this important data gap.”
An Easy-to-Use Database for an Alphabet Soup of Contaminants
Drinking water across the country is pulled from a variety of sources, from rivers and lakes to groundwater. It can become contaminated in a number of ways, including local industry, agriculture, and improper disposal of medicines. Recent analyses found 324 different contaminants in drinking water across the country, with nearly all community water systems having detectable contaminants — many of which are potentially carcinogenic. A 2019 EWG analysis found that contaminated drinking water could cause more than 100,000 additional cancer cases in the U.S.4
To help consumers identify the contaminants most likely to affect their water, EWG requested water contaminant data from public and environmental health agencies in all 50 states and the District of Columbia. After receiving more than 34 million records, EWG compiled them with the water quality data collected as part of EPA’s Unregulated Contaminants Monitoring Rule into the easy-to-use database.
To use the database, all you need to do is enter your ZIP code to show the most likely contaminants in your tap water. From there, you can use EWG’s handy water filter guide to identify which filter is best suited to keep your water free of the likely contaminants in your area.
What Types of Contaminants Are in Drinking Water?
Depending on where you live, you’ll encounter different contaminants in your water. Here are some of the most common contaminants — and how you can reduce your risk of exposure depending on which contaminant you’re dealing with.
PFAS, or “Forever Chemicals”
After rising to prominence in the ‘40s following the release of Teflon nonstick cookware, PFAS (per- and polyfluoroalkyl substances) became widespread in our environment. Research has since shown that PFAS can contribute to increased risk of some cancers, reduced immunity, and altered metabolism5. And these days, studies show that these “forever chemicals” are present in the blood of nearly all Americans (including newborns!), as well as the drinking water of more than 143 million people.
EPA has recently taken steps to eradicate these dangerous chemicals from the environment6. For Tasha Stoiber, Ph.D., a senior scientist at EWG, says the finalization of new federal drinking water standards for six PFAS in 2024 was “one of the most notable events” of late in the fight for clean drinking water7.
“This was especially significant because there has not been a new regulation for an unregulated drinking water contaminant passed in nearly 25 years,” Stoiber adds. “This example demonstrates that progress can be made under the Safe Drinking Water Act, but we need to make safe drinking water a priority.”
A major source of forever chemicals today comes from the Department of Defense, which relies on a PFAS-containing firefighting foam. EWG has mapped at least 720 military sites nationwide known or suspected of discharging these forever chemicals.
Activated carbon filters for water may help reduce the presence of PFAS in your household8.
Heavy Metals Remain Pervasive
Heavy metals were also extremely present in drinking water — particularly arsenic, hexavalent chromium, and lead.
Arsenic enters waterways either when natural mineral deposits erode and dissolve, or by way of contamination with industrial and agricultural waste products9. It can cause bladder, lung, and skin cancer, and is found in drinking water in all 50 states.
Hexavalent chromium, also known as chromium-6, is the heavy metal carcinogen made famous by the Erin Brockovich case in the ‘90s. It has been linked to cancer and organ damage and is present in the drinking water of over 250 million Americans. Despite these well-researched ties to cancer, there is no federal limit for chromium-6.
Lead is also present in some water systems due to lead service lines, though Stoiber notes that the EPA has taken steps to eradicate these with “updates to lead and copper regulations that required all lead pipes to be removed in 10 years.” Nevertheless, she says, “the fate of these new regulations is uncertain.”
If you live in an area served by lead-based lines, EWG suggests reducing the likelihood of contamination by flushing the pipes with cold water each morning and using only cold water for cooking.
Industrial Pollutants Persist at “Concerning Levels”
Volatile organic compounds (VOCs) like benzene and trichloroethylene are widespread industrial pollutants that have been found to contribute to increased cancer risk, liver damage, and neurological issues, even in small amounts. And according to EWG, they “persist in drinking water at concerning levels.”
In 2022, 198 million pounds of chemicals were discharged into rivers and streams by industrial businesses, according to the EPA’s Toxics Release Inventory reporting program. Activated carbon filtration is a good way to remove these contaminants from your drinking water.
Chlorine Contributes to Carcinogenic Disinfection Byproducts
Chlorine is a common disinfectant used to kill off dangerous pathogens and make drinking water safe. But when used in excess, chlorine may combine with organic matter to create dangerous “disinfection byproducts” in tap water, which EWG notes can contribute to reproductive health issues and increased risk of cancer. A new meta study in Environmental Health Perspective showed that chlorinating drinking water increases risk of bladder cancer by 33%9.
Even water systems with relatively low levels of contaminants could contain disinfection byproducts, Stoiber says. Luckily, she adds, “a simple table top carbon filter can remove these contaminants.”
Nitrogen and Phosphorus
Nitrogen and phosphorus are common contaminants, especially in agricultural communities. “Pollution from farms and factory farms is almost completely exempt from water pollution laws, including the Clean Water Act that was enacted more than 50 years ago,” writes EWG.
Every year, farmers across the country apply more than 12 million tons of nitrogen fertilizer and 4 million tons of phosphorus fertilizer to cropland, which can run off into water sources. Resulting nitrates have been found to contribute to increased risk of cancer and thyroid issues. Nitrate contamination is particularly dangerous for infants, EWG cautions.
A reverse osmosis filter is the only way to remove nitrates from water. For anyone preparing baby formula with potentially contaminated tap water, one of these filters is essential.
Why Bottled Water Isn’t Necessarily the Answer
Some people are more sensitive to contaminants than others and should exercise extra caution whenever possible. These include infants, children, the elderly, and people with compromised immunity due to chemotherapy or HIV/AIDS.
But EWG notes that in most cases, bottled water is not the answer. Not only are bottled water manufacturers not required to disclose the levels of contaminants in their products10, but bottled water may also be contaminated with nanoplastics11. Experts today posit that these bottled water nanoplastics are omnipresent potential carcinogens, so you may just be replacing one dangerous contaminant with another12.
Hold Officials Accountable for Providing Clean Drinking Water
While purchasing a water filter is one way to keep yourself safe from these contaminants, EWG also urges Americans to hold their elected officials accountable — the burden shouldn’t be on us to find clean drinking water.
“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,” writes EWG.
This is especially important if you live in an area where your water system serves only a handful of people. “These systems tend not to have as many resources for upgrades for treatment or as many options for water sources,” says Stoiber.
Sources:
- https://www.ewg.org/news-insights/news-release/2024/11/new-epa-data-show-millions-more-exposed-forever-chemicals
- https://www.congress.gov/104/plaws/publ182/PLAW-104publ182.pdf
- https://staging.ewg.org/tapwater/FAQ.php
- https://www.ewg.org/news-insights/news-release/ewg-study-estimates-more-100000-cancer-cases-could-stem-contaminants-tap
- https://www.niehs.nih.gov/health/topics/agents/pfc
- https://www.epa.gov/pfas/pfas-strategic-roadmap-epas-commitments-action-2021-2024
- https://www.ewg.org/news-insights/news/2024/04/what-do-new-federal-pfas-drinking-water-standards-mean
- https://www.ewg.org/tapwater/water-filter-ins-and-outs.php
- http://publichealth.lacounty.gov/eh/docs/safety/faq-arsenic-drinking-water.pdf
- https://pubmed.ncbi.nlm.nih.gov/39837568/
- https://www.nih.gov/news-events/nih-research-matters/plastic-particles-bottled-water
- https://pubmed.ncbi.nlm.nih.gov/36739075/
