10 States With The Dirtiest Tap Water

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Millions of Americans drink dangerous tap water every day. The crazy thing is notoriously tainted water sources here in America, like Flint Michigan’s, are a dime a dozen. That’s because water contamination that puts public health at risk extends far beyond publicized outbreaks, low income areas, and rural towns. Below we’ve dug into the data to highlight 10 of the worst water states in the U.S.

How We Determined These Rankings:

There’s no algorithm nor set standards for ranking statewide drinking water quality. Therefore, states are listed in no particular order. We reviewed the Environmental Protection Agency’s (EPA) Enforcement and Compliance History, the Environmental Working Group’s (EWG) Tap Water Database, years of test results, and a variety of reports and studies released by credible publications to compile this list. 

It is based on fact, not opinion nor politics. However, water quality is as fluid as water itself, and a new water crisis can emerge at any time. If your state isn’t on this list, that doesn’t mean your tap water is safe. Therefore, you should refer to our database to check your local tap water quality. Now let’s take a look at the states where water tends to be the dirtiest.

Who Has The Worst Tap Water In The United States?

Wisconsin has more than 150,000 lead service lines contaminating water at schools and in homes. While lead is a serious problem, the state is most known for widespread nitrate contamination. Nitrate is Wisconsin’s most prevalent groundwater contaminant due to agricultural activities. The scariest part is 70% of residents get their drinking water from groundwater. Plus, Trihalomethanes (TTHMs), bromodichloromethane, HAA5, and several others contaminants have been served to millions of people at levels exceeding EWG health guidelines

  • Widespread lead contamination affects children and adults. Wisconsin’s most populous city, Milwaukee, has approximately 70,000 lead pipes

  • Rampant nitrate contamination could impact as much as 70% of the state’s residents.

  • Millions of people have been served water with several contaminants above EWG health guidelines. Plus,150,000 residents have been served water with radium above legal limits.

Long considered some of the most dangerous water in the nation as evidenced by this 2017 report, Georgia faces a myriad of issues threatening its public water supplies. Several of them are outlined in the state’s annual ‘Dirty Dozen’ report. Common and consistent threats include everything from coal ash contamination to sewage overflows and landfill failures, while new reports and lawsuits seem to pop up regularly. Many of the state’s water supplies have been plagued by PFAS for years, tens of thousands of people are affected by Trihalomethanes (TTHMs), and uranium levels above legal limits, and millions are served water with a variety of contaminants above EWG’s health guidelines.

A 2016 EWG report revealed Phoenix’s public water supply, which serves more than 1.5 million Arizona residents, had the highest average levels of cancer-causing chromium-6 in the nation. Not only does Arizona’s most populous city have a track record of contamination, its second most populous city, Tucson, had to shut down one of the city’s water treatment facilities that serves more than 60,000 people due to a surge in cancer-linked “forever chemicals” known as PFAS. Beyond chromium-6 and PFAS, EWG data shows thousands of residents are served Nitrate, Trihalomethanes (TTHMs), and Arsenic above legal limits, while millions are served a plethora of contaminants above EWG health guidelines. 

  • Chromium-6 contamination has affected more than 1.5 million people in Phoenix. Chromium-6 is a carcinogen. In other words, it can cause cancer.

  • PFAS contamination affected tens of thousands in Tucson in 2021.

  • Widespread contamination affects millions of residents.

Waste in dozens of old coal mining towns pollute Pennsylvania’s air and water. Thousands of miles of polluted streams plague public water supplies too (in some cases, acid mine drainage leaves these streams in shades of orange and red). Plus, abandoned gas and oil wells can overflow during rainfall pouring pollution into groundwater and surface water. Remember, groundwater and surface water flow into public water supplies and are essential sources of well water.

Smaller towns have long lacked the resources to even perform mandatory water inspections in the state, leaving many wondering what’s in their water. While bigger towns, like Pittsburgh, have had their fair share of struggles keeping water clean, putting hundreds of thousands of residents at risk regularly. The Steel City even had to shut down schools due to contaminated water just a few years ago. Plus, EPA records show statewide public water systems have gone from bad to worse in recent years.

Key Findings:

  • Thousands of miles of polluted streams serve contaminated water to millions.

  • Water suppliers deemed “serious violators” by the EPA more than doubled from 141 in 2015 to 349 in 2020

  • 3788 public water suppliers received at least one federal violation last year. For comparison, just 1550 California public water suppliers received violations during the same timeframe.

Like California, Texas is often considered the poster child of dirty water. Nearly 12 million Texans were told to boil their water before drinking it after an unprecedented winter storm led to blackouts that disrupted and damaged water treatment facilities earlier this year. 

Beyond recent issues, Texas has long had trouble maintaining water quality. Aging infrastructure has caused dangerous lead and arsenic contamination. Rural communities lack the resources to properly filter contaminated groundwater. And in 2018, the state had the most radiated drinking water in the country with 80 percent of its 28 million residents at risk.

Key Findings:

Florida’s public water supplies are often victims of natural disasters. Hurricanes and heavy storms cause floods that pour contaminants into public waterways and systems. Algal blooms call for an abundance of fertilizer that can end up in drinking water. Plus, saltwater is making its way inland and contaminating underground water supplies that serve millions. Even big cities are at risk: Miami’s tap water had one of the highest concentrations of hormone-disrupting PFAS, also known as forever chemicals, in the nation according to test results released by the EWG last year.


New Jersey’s largest city, Newark, was the Flint Michigan of 2019. Testing from January to June ‘19 revealed lead levels in drinking water were more than 3x legal limits. Unfortunately, lead wasn’t the only issue: Nine of the city’s 12 testing sites also had high levels of Haloacetic acids (HAAs). Long-term exposure to HAAs has been associated with various types of cancer, as well as liver and kidney issues. Plus, more than 5 million New Jersey residents were exposed to drinking water that tested positive for chloroform around the same time. As of late, several New Jersey towns have been issued boil water advisories due to damaged and aging infrastructure, proving a litany of issues continue to affect the state’s water sources.

Key Findings:

A 2019 report by Environment Washington revealed more than 60% of taps tested at schools and preschools had detectable levels of lead in their water, 97% of schools had at least one faucet with lead concentration exceeding levels recommended by The American Academy of Pediatrics, and the state received an ‘F’ grade for its lack of effort to remove lead from school drinking water. 

While recent legislation requires Washington schools to test water outlets for lead, EPA data shows serious tap water violators continued to rise in 2020. Meanwhile, a decommissioned nuclear facility, referred to as an “underground Chernobyl,” looms as perhaps the largest threat to the state’s water supplies as 56 million gallons of radioactive waste buried underground contaminante groundwater that flows into public water supplies. 

Key Findings:

It’s no secret The Golden State struggles with water quality as residents have long dreamed of clean water. Lead issues have been prevalent for decades. Arsenic, uranium, and nitrate are common in the state’s sprawling Central Valley, as well as its other massive farming zones where herbicides and pesticides are all but guaranteed. To top it off, several other California communities have a history atop lists like these. 

Meanwhile, droughts can actually increase concentration of contaminants in drinking water systems. Wildfires torch infrastructure and leave ash, chemicals, and debris in their tracks. Plus, the chemicals used to fight fires can actually sneak into water supplies and accelerate water contamination (or introduce new contaminants). These issues affect millions as California is our nation’s most populous state. 

Key Findings:

  • Contaminants found above legal limits are served to hundreds of thousands of residents annually and contaminants found above health guidelines are served to tens of millions. 

  • California has a long history of consistently contaminated water.

  • Perennial wildfires and ongoing agricultural issues exacerbate the problem throughout the state.

In the past, Ohio has been a staple on lists like these. However, Ohio has been cleaning up its act as of late, while another midwest state, Illinois, has gone in the opposite direction. Widespread lead contamination and an exponential increase in EPA violations the past few years put the Land of Lincoln on this list. As you can see here, public water suppliers designated as “serious violators” by the EPA skyrocketed from 68 in 2018 to 553 in 2019. That’s an alarming 8x increase in just one year. Meanwhile, the number of public water suppliers that received any EPA violation also multiplied from 2015 to 2020.

The Chicago Tribune recently found more than 8 out of every 10 Illinois residents live in a community where lead has been detected in tap water. It’s unlikely things get better anytime soon, as the state has the most lead service pipes in the country. In other words, until those pipes are replaced, lead will continue to leach into public water supplies at ease. The good news is Illinois passed a bill that requires the removal of its remaining lead services lines. The bad news is the project will take decades to complete, and lead isn’t the only problem plaguing Illinois’ water supplies. The EWG has detected more than 80 other contaminants floating around.

Key Findings:

  • Municipalities with at least one EPA violation jumped from 493 to 1840 from 2015 to 2020

  • Water suppliers designated as “serious violators” by the EPA increased 8x from 2018 to 2019.

  • At time of publication, a water crisis was brought to light as toxic lead contamination was detected in several of the most populous areas of the state.

Honorable Mention: Puerto Rico

Perhaps you expected to see New Mexico, New York, Nevada, or Nebraska here. The truth is you can find widespread water pollution in almost every state. To avoid this list being 50 states long, Puerto Rico—a territory, not a state—gets its own shoutout. In 2015, 99.5% of Puerto Rico’s population was served tap water that violated the Safe Water Drinking Act according to the National Resources Defense Council (NRDC). Then in 2017, Hurricanes Irma and Maria devastated the island, leading to more violations. As of late, EPA data shows little improvement in water quality.

Key Findings:

  • More than 2 million people were served water that violated federal standards in 2015.

  • 97% of the population got its water from public water systems cited for at least one violation of lead and copper testing requirements between 2015 and 2018.

How Does Contamination Happen?

Here are some of the ways public water supplies are contaminated: 

Damaged, aging, and neglected infrastructure. Lead service lines, leaky pipes, and old infrastructure can lead to chemical leaching. Related contamination goes far beyond the sediment typically found in older systems.

Runoff. Chemicals from manufacturing and industrial processes, as well as farming and agriculture can find their way into public water supplies due to runoff caused by rain, flooding, melted snow, and other environmental factors.

Lack of funding. Many municipalities are aware of problems, but lack the funds to fix them. Federal investment in water infrastructure peaked in 1977.

Natural disasters and disruption. Wildfires, floods, blackouts, and more can disrupt water treatment facilities, almost instantly making water unsafe to drink. Plants can even get struck by lightning.

Mismanaged water treatment. Water treatment is a delicate balancing act. New contaminants emerge by treatment and by accident all the time. 

Unregulated chemicals. Hundreds of chemicals are unregulated by federal drinking water standards. Therefore, there are no laws preventing them from polluting public water supplies.  

A Note on Bottled Water

When clean water isn’t a given, many turn to bottled water. The unfortunate truth is bottled water can be just as dirty as your local water supply. Unlike tap water, which is regulated by the EPA and held to the standards set in the Safe Drinking Water Act (SDWA), bottled water is regulated by the U.S. Food and Drug Administration (FDA). The two organizations share nearly identical standards for water quality. Plus, that plastic packaging can do tremendous harm to oceans, wildlife, landfills, air, and of course, your health. Before you crack a bottle in search of clean water, check this out.

The Best Way to Protect Yourself From Dirty Water

As you can see, our nation lacks stringent water standards to ensure we only drink the cleanest water. The best way to avoid dirty water is to invest in a water filter proven to filter common and covert contaminants from pesticides to fluoride, PFAS, HAA5, and more. Protect yourself, your family, and your future—take a look at our full line of advanced filtration systems and breakthrough water filters here.


1. Analyze Trends: EPA/State Drinking Water Dashboard https://echo.epa.gov/trends/comparative-maps-dashboards/drinking-water-dashboard

2. Latest Wisconsin data on water service lines provides important insights, reveals over 150,000 lead pipes https://blogs.edf.org/health/2020/04/16/latest-wisconsin-data-on-water-service-lines-provides-important-insights-reveals-over-150000-lead-pipes/

3. Nitrate webinar series planned https://www.leadertelegram.com/country-today/environment/nitrate-webinar-series-planned/article_daac88d3-9f93-5e51-afeb-cda0b181e6b9.html

4. Wisconsin https://www.ewg.org/tapwater/state.php?stab=WI

5. Madison - Milwaukee Lead Copper Rule (LCR) Data Comparison (2011-2017) and Beyond https://city.milwaukee.gov/ImageLibrary/Groups/WaterWorks/Lead-Service-Lines/LCR_Madison_Milwaukee_Comparison_Report_Beversdorf.pdf

6. Georgia Drinking Water Among Nation's Least Safe: Report https://patch.com/georgia/peachtreecorners/georgia-drinking-water-among-nations-least-safe-report

7. Annual ‘Dirty Dozen’ report details water concerns across Georgia https://www.ajc.com/news/annual-dirty-dozen-report-details-water-concerns-across-georgia/7IAMDYFMO5BYXIMHA7NAZ46FCE/

8. Federal prisoners sue Atlanta over drinking water contamination claims https://www.ajc.com/news/atlanta-news/federal-prisoners-sue-atlanta-over-drinking-water-contamination-claims/BDTPUCMVR5C2LLOM4XRR7B2FWY/

9. Georgia City Resident Sues Over Chemical Discharge in Water https://www.insurancejournal.com/news/southeast/2021/03/17/605848.htm

10. Cancer causing chemical found in Ga. drinking water remains unregulated five years after EPA warning https://www.11alive.com/article/news/investigations/the-reveal/rome-contaminated-water-investigation/85-273c7fdd-1097-4b26-b3cf-0242231762a4

11. Georgia https://www.ewg.org/tapwater/state.php?stab=GA

12. Cancer-Linked Contaminants Found In Atlanta Water: Report https://patch.com/georgia/atlanta/cancer-linked-contaminants-found-atlanta-water-report

13. 'Erin Brockovich' Carcinogen in Tap Water of More than 200 Million Americans https://www.ewg.org/research/erin-brockovich-carcinogen-tap-water-more-200-million-americans

14. ‘Ticking time bomb’: PFAS chemicals in drinking water alarm scientists over health risks https://www.connectradio.fm/2021/08/10/ticking-time-bomb-pfas-chemicals-in-drinking-water-alarm-scientists-over-health-risks/

15. Arizona https://www.ewg.org/tapwater/state.php?stab=AZ

16. Orange water, dirty air: What will it take to clean up abandoned mine land in the Chesapeake watershed? https://www.bayjournal.com/news/energy/orange-water-dirty-air-what-will-it-take-to-clean-up-abandoned-mine-land-in/article_dd947c74-7b66-11eb-81e3-232de92f42f3.html

17. Pennsylvania must act to stem pollution flowing to Chesapeake Bay https://www.goerie.com/story/opinion/columns/2021/04/08/pennfuture-pennsylvania-must-stem-pollution-flowing-chesapeake-bay/7091985002/

18. https://www.post-gazette.com/local/city/2017/01/31/Half-of-PWSA-s-customers-ordered-to-boil-water-due-to-unspecified-problem/stories/201701310270

19. Texas weather: Residents told to boil tap water amid power blackouts https://www.bbc.com/news/world-us-canada-56109720

20. Radium contamination in water most widespread in Texas, environmental group says https://www.cbsnews.com/news/drinking-water-radium-contamination-cancer/

21. Texas https://www.ewg.org/tapwater/state.php?stab=TX

22. Report: Florida's Algal Bloom Problems Will Only Grow Worse https://thebradentontimes.com/stories/report-floridas-algal-bloom-problems-will-only-grow-worse,27585

23. Will Florida be lost forever to the climate crisis? https://www.theguardian.com/environment/2020/apr/21/florida-climate-crisis-sea-level-habitat-loss

24. PFAS Contamination of Drinking Water Far More Prevalent Than Previously Reported https://www.ewg.org/research/national-pfas-testing

25. Miami-Dade to sue makers of cancer-linked chemicals PFAS https://www.miamitodaynews.com/2020/07/21/miami-dade-to-sue-makers-of-cancer-linked-chemicals-pfas/

26. 12 cities with the worst tap water in the US https://www.businessinsider.com/cities-worst-tap-water-us-2019-3#newarks-lead-contamination-is-at-an-all-time-high-5

27. New Jersey, your tap water may be contaminated with carcinogens https://www.app.com/story/news/local/land-environment/2019/10/25/nj-water-contamination-your-tap-water-safe/4083549002/

28. Boil water advisory issued for towns central New Jersey https://abc7ny.com/boil-water-advisory-new-jersey-american-company-tap-contamination/10927014/

29. The places across N.J. where too much lead has been found in the water https://www.nj.com/news/2019/04/the-places-across-nj-where-too-much-lead-has-been-found-in-the-water.html

30. Newark’s water breaches levels for dangerous contaminant. And nearby towns are drinking it, too. https://www.nj.com/essex/2018/11/newark_cancer-causing_chemical_water.html

31. Lead in the Water: Statewide Data Reveals Elevated Levels of Lead in School Drinking Water in Washington https://environmentamerica.org/washington/wp-content/uploads/2019/02/Lead-in-the-Water-Statewide-Data-Reveals-Elevated-Levels-of-Lead-in-School-Drinking-Water-in-Washington.pdf

32. National report gives Washington state an ‘F’ for efforts to remove lead from school drinking water https://www.seattletimes.com/education-lab/national-report-gives-washington-state-an-f-for-efforts-to-remove-lead-from-school-drinking-water/

33. The Columbia River passes Hanford to the north and the east by a few miles, and it's downstream from two dams. https://www.businessinsider.com/hanford-nuclear-site-photos-toxic-waste-2019-9#the-columbia-river-passes-hanford-to-the-north-and-the-east-by-a-few-miles-and-its-downstream-from-two-dams-2

34. Radioactive Waste Still Flooding Columbia River, EPA Says https://www.courthousenews.com/radioactive-waste-still-flooding-columbia-river-epa-says/

35. Washington https://www.ewg.org/tapwater/state.php?stab=WA

36. 100,000 Central Valley residents impacted by contaminated drinking water will soon see interim solutions https://www.waterboards.ca.gov/press_room/press_releases/2021/pr03152021_r5_residents_impacted_by_nitrate_in_gw.pdf

37. California’s wildfires are poisoning drinking water supplies https://massivesci.com/articles/california-wildfires-drinking-water-lead-pipes/

38. Wildfires Can Spark Widespread Contamination of Public Water Supplies https://www.nrdc.org/stories/wildfires-can-spark-widespread-contamination-public-water-supplies

39. Ohio has second most lead water-supply pipes in U.S.; infrastructure plan would replace them https://www.dispatch.com/story/news/2021/07/30/ohio-infrastructure-plan-water-supply-pipes-lead-poisoning/8018241002/

40. Illinois Takes a Major Step Toward Replacing Its Lead Service Lines https://www.nrdc.org/bio/nrdc/illinois-takes-major-step-toward-replacing-its-lead-service-lines

41. Illinois https://www.ewg.org/tapwater/state.php?stab=IL

42. City of Lynn Haven issues water boil notice https://www.mypanhandle.com/news/local-news/city-of-lynn-haven-issues-water-boil-notice/

43. US EPA. National Primary Drinking Water Regulations. Accessed September 2, 2019 https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations

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