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The 50 lowest-scoring cities among the 760 we grade from EPA records: health-based violations in the last five years, Lead and Copper Rule 90th-percentile results, PFAS in EPA's 2023–2026 UCMR5 monitoring and 2012–2019 compliance samples near or above a limit (methodology). Residents in these areas should strongly consider a certified water filter matched to the finding on their city page.
If your city appears on this list, we strongly recommend using a certified water filter to protect your family's health. Pay special attention to the specific contaminants found in your city's water.
View Filter RecommendationsYou can't change your utility's source water, but you can filter what comes out of your own tap. The catch: the contaminants that land a city on this list — lead, arsenic, nitrate and PFAS — are exactly the ones a basic carbon pitcher does not remove. To actually reduce them you need a reverse-osmosis system. Here are the two places to start, from most thorough to cheapest.
APEC ROES-50 Reverse Osmosis
5-stage under-sink RO system · ~$200
Removes 95–99% of lead, arsenic, nitrate, fluoride and PFAS — the widest range of any filter type. The right choice if your city's report shows any of these.
Check Price on AmazonZeroWater 10-Cup Pitcher
NSF 53 certified pitcher · ~$40
NSF 53 certified to reduce lead, chromium & dissolved solids — no installation needed, the cheapest way to start while you plan a permanent fix.
Check Price on AmazonNot sure which contaminants are in your water?
A home test kit shows exactly what's in your tap before you buy a filter — municipal reports don't include the lead from your own plumbing.
Shop Home Water Test Kits →We may earn a commission when you purchase through our links, at no extra cost to you.
Click any city to see detailed water quality report including specific contaminants, violations, and recommended filters.
| Rank | City | State | Score | Grade | Population Affected |
|---|---|---|---|---|---|
| #1 | Lauderhill | Florida | 21/100 | F | 55,000 |
| #2 | Syracuse | New York | 29/100 | F | 192,000 |
| #3 | Valdosta | Georgia | 33/100 | F | 48,959 |
| #4 | Yucaipa | California | 34/100 | F | 52,010 |
| #5 | Hallandale Beach | Florida | 34/100 | F | 40,000 |
| #6 | Dania Beach | Florida | 34/100 | F | 30,000 |
| #7 | Porterville | California | 43/100 | F | 63,487 |
| #8 | Bullhead City | Arizona | 44/100 | F | 36,330 |
| #9 | Prescott | Arizona | 51/100 | F | 42,217 |
| #10 | Prichard | Alabama | 52/100 | F | 29,190 |
| #11 | Yuma | Arizona | 53/100 | F | 103,264 |
| #12 | Pembroke Pines | Florida | 54/100 | F | 187,459 |
| #13 | Palm Bay | Florida | 54/100 | F | 140,750 |
| #14 | Goodyear | Arizona | 54/100 | F | 50,001 |
| #15 | Riviera Beach | Florida | 54/100 | F | 46,762 |
| #16 | Union City | Georgia | 54/100 | F | 18,636 |
| #17 | Calumet City | Illinois | 55/100 | F | 37,000 |
| #18 | Junction City | Kansas | 55/100 | F | 19,167 |
| #19 | Stockton | California | 56/100 | F | 191,302 |
| #20 | Shreveport | Louisiana | 57/100 | F | 192,378 |
| #21 | Medford | Massachusetts | 57/100 | F | 61,700 |
| #22 | San Luis | Arizona | 57/100 | F | 39,705 |
| #23 | New Orleans | Louisiana | 58/100 | F | 334,903 |
| #24 | Monroe | Louisiana | 58/100 | F | 57,000 |
| #25 | Andover | Massachusetts | 58/100 | F | 36,569 |
| #26 | Lawrence | Indiana | 59/100 | F | 49,000 |
| #27 | Opelousas | Louisiana | 60/100 | D | 20,388 |
| #28 | Gilbert | Arizona | 61/100 | D | 247,600 |
| #29 | Modesto | California | 61/100 | D | 218,771 |
| #30 | Joliet | Illinois | 61/100 | D | 160,000 |
| #31 | Miami Beach | Florida | 61/100 | D | 100,000 |
| #32 | Pinellas Park | Florida | 61/100 | D | 48,939 |
| #33 | Alabaster | Alabama | 61/100 | D | 40,986 |
| #34 | West Palm Beach | Florida | 62/100 | D | 132,000 |
| #35 | Elgin | Illinois | 63/100 | D | 114,797 |
| #36 | Winter Haven | Florida | 63/100 | D | 87,537 |
| #37 | Hialeah | Florida | 64/100 | D | 238,000 |
| #38 | Fort Lauderdale | Florida | 64/100 | D | 185,163 |
| #39 | Ontario | California | 64/100 | D | 185,010 |
| #40 | Hollywood | Florida | 64/100 | D | 147,566 |
| #41 | Pompano Beach | Florida | 64/100 | D | 99,400 |
| #42 | North Miami | Florida | 64/100 | D | 89,349 |
| #43 | Naples | Florida | 64/100 | D | 83,804 |
| #44 | Sunrise | Florida | 64/100 | D | 79,550 |
| #45 | Coral Springs | Florida | 64/100 | D | 65,000 |
| #46 | Tamarac | Florida | 64/100 | D | 63,793 |
| #47 | Margate | Florida | 64/100 | D | 62,254 |
| #48 | Gilroy | California | 64/100 | D | 59,203 |
| #49 | Fort Pierce | Florida | 64/100 | D | 58,000 |
| #50 | Brighton | Colorado | 64/100 | D | 56,304 |
Lead 90th-percentile results at or near the 15 ppb action level, PFOA/PFOS at or above the 4 ppt federal limit, or 2012–2019 samples of arsenic, nitrate, radium or disinfection byproducts averaging near or above the MCL.
Multiple or recent violations of Safe Drinking Water Act requirements, including health-based violations or failure to properly monitor.
Health-based violations still listed as unaddressed with EPA or the state cost an extra 20 points — a resolved problem is graded more leniently than an open one.
Contamination from agricultural runoff, industrial discharge, or naturally occurring minerals in the source water supply.
Most low grades on this list trace back to one of four contaminants. Each needs a different filter. Pick yours to see what it does to your health and which certified filter removes it.
Removed by: NSF 53 carbon or NSF 58 reverse osmosis
Best filters for lead →Lead health risks & limitsRemoved by: Reverse osmosis (NSF 58) or NSF 53 carbon block
Best filters for PFAS →PFAS health risks & limitsRemoved by: Under-sink reverse osmosis (NSF 58)
Best filters for arsenic →Arsenic health risks & limitsRemoved by: Reverse osmosis or ion exchange
Best filters for nitrates →Nitrates health risks & limitsClick on your city above to see the specific contaminants and violations affecting your water. Understanding the exact issues is the first step to protection.
Choose a filter certified to remove the specific contaminants in your water. Not all filters remove all contaminants. Look for NSF certification for your concerns.
Municipal testing doesn't include your home plumbing. Home tests can identify lead from pipes or other issues specific to your residence.
Review your water utility's annual Consumer Confidence Report. Attend public meetings about water quality and advocate for infrastructure improvements.
Water quality varies over time, but cities commonly cited for water quality issues include Flint, Michigan (historic lead crisis), Newark, New Jersey (lead contamination), and various cities in Texas and California with elevated arsenic or PFAS levels. Check our updated rankings for the current worst-rated cities based on EPA data.
A low score on this site comes from real EPA records: 1) health-based violations (MCL or treatment-technique) in the last five years, 2) violations still unresolved with EPA or the state, 3) a lead 90th-percentile result at or near the 15 ppb action level, 4) PFOA or PFOS at or above the 4 ppt federal limit in UCMR5 monitoring, and 5) 2012–2019 compliance samples averaging near or above a limit for arsenic, nitrate, radium or disinfection byproducts.
If your city has poor water quality: 1) Install a certified water filter matched to your specific contaminants (reverse osmosis for lead/PFAS/arsenic), 2) Use only cold water for drinking and cooking, 3) Run water for 30 seconds before use, 4) Consider having your home water tested, 5) Stay informed through your utility's annual water quality report.
Bottled water can be a temporary solution but is expensive and creates plastic waste. A better long-term solution is installing a certified water filter. Reverse osmosis systems remove 95-99% of contaminants including lead, arsenic, and PFAS, and provide safe water at a fraction of the cost of bottled water over time.
Water quality differences stem from: 1) Natural geology (arsenic, radium occur naturally in some regions), 2) Industrial history (legacy contamination near factories, military bases), 3) Infrastructure age (older pipes, lead service lines), 4) Funding levels (wealthier cities invest more in water treatment), 5) Source water quality (surface water vs groundwater, upstream pollution).