Top 50 Cities with the Most Concerning Water Quality
These cities have significant water quality challenges based on EPA contaminant data, compliance violations, and infrastructure concerns. Residents in these areas should strongly consider using certified water filters.
Important Notice for Residents
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 RecommendationsKey Statistics
States with Most Cities in Bottom 50
Complete Rankings: Cities with Most Concerns
Click any city to see detailed water quality report including specific contaminants, violations, and recommended filters.
| Rank | City | State | Score | Grade | Population Affected |
|---|---|---|---|---|---|
| #1 | Alameda | California | 44/100 | F | 79,827 |
| #2 | Union City | Georgia | 44/100 | F | 22,329 |
| #3 | San Bernardino | California | 45/100 | F | 222,101 |
| #4 | San Marcos | California | 45/100 | F | 97,477 |
| #5 | Windsor | Colorado | 45/100 | F | 32,551 |
| #6 | Mishawaka | Indiana | 46/100 | F | 51,063 |
| #7 | Bardstown | Kentucky | 46/100 | F | 13,567 |
| #8 | Indio | California | 47/100 | F | 92,301 |
| #9 | San Jose | California | 47/100 | F | 1,013,240 |
| #10 | Safety Harbor | Florida | 47/100 | F | 17,203 |
| #11 | Hanover Park | Illinois | 47/100 | F | 38,510 |
| #12 | Cape Coral | Florida | 48/100 | F | 194,016 |
| #13 | Plantation | Florida | 48/100 | F | 94,366 |
| #14 | Dalton | Georgia | 48/100 | F | 34,417 |
| #15 | Lenexa | Kansas | 48/100 | F | 57,434 |
| #16 | San Buenaventura | California | 49/100 | F | 110,763 |
| #17 | Arvada | Colorado | 49/100 | F | 124,402 |
| #18 | Wheat Ridge | Colorado | 49/100 | F | 32,133 |
| #19 | Jacksonville | Florida | 49/100 | F | 949,611 |
| #20 | Woodland | California | 50/100 | D | 61,032 |
| #21 | Peachtree City | Georgia | 50/100 | D | 38,633 |
| #22 | Hagerstown | Maryland | 50/100 | D | 43,527 |
| #23 | Nogales | Arizona | 51/100 | D | 20,103 |
| #24 | Durango | Colorado | 51/100 | D | 19,399 |
| #25 | Coral Springs | Florida | 51/100 | D | 133,759 |
| #26 | Parkland | Florida | 51/100 | D | 34,670 |
| #27 | Oswego | Illinois | 51/100 | D | 34,485 |
| #28 | Scottsdale | Arizona | 52/100 | D | 241,361 |
| #29 | Santa Clara | California | 52/100 | D | 127,134 |
| #30 | Houma | Louisiana | 52/100 | D | 33,727 |
| #31 | Parker | Colorado | 53/100 | D | 58,512 |
| #32 | Belleville | Illinois | 53/100 | D | 41,097 |
| #33 | Palatine | Illinois | 53/100 | D | 69,350 |
| #34 | Garden Grove | California | 54/100 | D | 172,800 |
| #35 | Alexandria | Louisiana | 54/100 | D | 45,275 |
| #36 | Quincy | Massachusetts | 54/100 | D | 101,636 |
| #37 | El Mirage | Arizona | 55/100 | C- | 35,753 |
| #38 | Palm Bay | Florida | 55/100 | C- | 119,760 |
| #39 | Aurora | Illinois | 55/100 | C- | 177,564 |
| #40 | Germantown | Maryland | 55/100 | C- | 91,249 |
| #41 | Kenai | Alaska | 56/100 | C- | 7,424 |
| #42 | Paradise Valley | Arizona | 56/100 | C- | 14,502 |
| #43 | Encinitas | California | 56/100 | C- | 62,671 |
| #44 | Mission Viejo | California | 56/100 | C- | 95,638 |
| #45 | North Miami | Florida | 56/100 | C- | 62,468 |
| #46 | St. Petersburg | Florida | 56/100 | C- | 258,308 |
| #47 | Baton Rouge | Louisiana | 56/100 | C- | 227,470 |
| #48 | Lake Charles | Louisiana | 56/100 | C- | 84,872 |
| #49 | Prescott | Arizona | 57/100 | C- | 43,376 |
| #50 | Pooler | Georgia | 57/100 | C- | 25,711 |
Common Water Quality Issues in These Cities
Elevated Contaminants
Contaminants like lead, arsenic, nitrates, or disinfection byproducts found at levels approaching or exceeding EPA maximum limits.
EPA Violations
Multiple or recent violations of Safe Drinking Water Act requirements, including health-based violations or failure to properly monitor.
Aging Infrastructure
Old pipes, outdated treatment facilities, or inadequate distribution systems that contribute to water quality degradation.
Source Water Issues
Contamination from agricultural runoff, industrial discharge, or naturally occurring minerals in the source water supply.
What Should Residents Do?
Check Your City's Report
Click on your city above to see the specific contaminants and violations affecting your water. Understanding the exact issues is the first step to protection.
Get the Right Water Filter
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.
Consider Home Testing
Municipal testing doesn't include your home plumbing. Home tests can identify lead from pipes or other issues specific to your residence.
Stay Informed
Review your water utility's annual Consumer Confidence Report. Attend public meetings about water quality and advocate for infrastructure improvements.