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EPA VIOLATIONS — 2025 SDWIS DATA
US cities with the most EPA drinking water violations
The EPA's Safe Drinking Water Information System tracks violations at every public water system in the country. A violation means a utility failed to meet a federal standard — either by exceeding a maximum contaminant level, failing to monitor, or failing to notify residents. Here are the cities with the worst records.
79
Cities rated high concern
53
Cities flagged to monitor
135+
Cities tracked by WaterCheckup
WHAT AN EPA VIOLATION ACTUALLY MEANS
A violation doesn't always mean your water is dangerous right now — but it does mean your utility failed to meet a federal standard at some point. Health-based violations (exceeding a maximum contaminant level) are the most serious. Monitoring violations mean the utility failed to test and report as required.
Importantly, EPA legal limits are set based on what's technically and economically feasible — not always what independent health scientists consider safe. A system with zero violations can still have water quality concerns.
ALL 135 CITIES — RANKED BY VIOLATION CONCERN
1
Las Vegas, NVHigh concern
Extremely hard water · 650K residents
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2
New Orleans, LAHigh concern
Lead contamination · 380K residents
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3
San Diego, CAHigh concern
Imported water vulnerability · 1.4M residents
Report →
4
Bakersfield, CAHigh concern
1,2,3-TCP pesticide · 380K residents
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5
Henderson, NVHigh concern
Extremely hard water · 320K residents
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6
Scottsdale, AZHigh concern
Hard water · 240K residents
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7
Chula Vista, CAHigh concern
Chromium-6 · 270K residents
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8
Chicago, ILHigh concern
Lead service lines · 2.7M residents
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9
Los Angeles, CAHigh concern
Chromium-6 (hexavalent chromium) · 4M residents
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10
Phoenix, AZHigh concern
High TDS / hard water · 1.6M residents
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11
Philadelphia, PAHigh concern
Lead service lines · 1.6M residents
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12
Miami, FLHigh concern
PFAS contamination · 470K residents
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13
Detroit, MIHigh concern
Lead service lines · 630K residents
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14
Baltimore, MDHigh concern
Lead service lines · 580K residents
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15
Memphis, TNHigh concern
PFAS contamination · 630K residents
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16
Louisville, KYHigh concern
Ohio River contamination · 630K residents
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17
Cleveland, OHHigh concern
Lead service lines · 370K residents
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18
Pittsburgh, PAHigh concern
Lead contamination crisis · 300K residents
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19
Charlotte, NCHigh concern
GenX / PFAS contamination · 900K residents
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20
Raleigh, NCHigh concern
GenX and PFAS · 470K residents
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21
St. Louis, MOHigh concern
Mississippi River contamination · 300K residents
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22
Salt Lake City, UTHigh concern
PFAS from Hill AFB · 200K residents
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23
Albuquerque, NMHigh concern
Arsenic in groundwater · 560K residents
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24
Tucson, AZHigh concern
PFAS from military sites · 540K residents
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25
San Jose, CAHigh concern
Chromium-6 · 1M residents
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26
Washington DC, DCHigh concern
Lead service lines · 700K residents
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27
Milwaukee, WIHigh concern
Lead service lines · 590K residents
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28
Honolulu, HIHigh concern
Agricultural pesticide runoff · 350K residents
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29
Baton Rouge, LAHigh concern
Mississippi River contamination · 230K residents
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30
El Paso, TXHigh concern
Arsenic in groundwater · 680K residents
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31
Fresno, CAHigh concern
Arsenic from San Joaquin Valley geology · 540K residents
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32
Mesa, AZHigh concern
Hard water / high TDS · 500K residents
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33
Virginia Beach, VAHigh concern
PFAS from Naval Air Station Oceana · 460K residents
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34
Long Beach, CAHigh concern
Chromium-6 · 460K residents
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35
Colorado Springs, COHigh concern
PFAS from Peterson SFB · 480K residents
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36
Aurora, COHigh concern
PFAS from Buckley SFB · 370K residents
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37
Anaheim, CAHigh concern
Nitrates from agriculture · 350K residents
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38
Riverside, CAHigh concern
Nitrates from citrus agriculture · 310K residents
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39
Stockton, CAHigh concern
Arsenic · 310K residents
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40
St. Paul, MNHigh concern
PFAS from 3M industrial sites · 310K residents
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41
Greensboro, NCHigh concern
GenX / PFAS · 290K residents
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42
Toledo, OHHigh concern
Lake Erie algal blooms / cyanotoxins · 270K residents
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43
Newark, NJHigh concern
Lead contamination crisis · 310K residents
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44
Chandler, AZHigh concern
Hard water / high TDS · 280K residents
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45
Laredo, TXHigh concern
Rio Grande contamination · 260K residents
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46
Madison, WIHigh concern
PFAS from 3M / industrial sources · 270K residents
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47
Durham, NCHigh concern
GenX / PFAS · 280K residents
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48
Lubbock, TXHigh concern
Nitrates from agriculture · 260K residents
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49
Winston-Salem, NCHigh concern
PFAS / GenX contamination · 250K residents
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50
Norfolk, VAHigh concern
PFAS from Naval Station Norfolk · 240K residents
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51
Jersey City, NJHigh concern
Lead from aging infrastructure · 290K residents
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52
Gilbert, AZHigh concern
Hard water / high TDS · 260K residents
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53
Glendale, AZHigh concern
Hard water / high TDS · 250K residents
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54
Hialeah, FLHigh concern
PFAS contamination · 220K residents
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55
Fremont, CAHigh concern
PFAS from industrial sites · 230K residents
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56
Birmingham, ALHigh concern
Industrial legacy contamination · 210K residents
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57
Rochester, NYHigh concern
Lead service lines · 210K residents
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58
Des Moines, IAHigh concern
Nitrates from agricultural runoff · 215K residents
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59
Fayetteville, NCHigh concern
GenX / PFAS -- ground zero · 210K residents
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60
Tacoma, WAHigh concern
PFAS from Joint Base Lewis-McChord · 220K residents
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61
Akron, OHHigh concern
Lead service lines · 190K residents
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62
Huntsville, ALHigh concern
PFAS from Redstone Arsenal · 215K residents
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63
Grand Rapids, MIHigh concern
PFAS from 3M/industrial sources · 195K residents
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64
Dayton, OHHigh concern
PFAS from Wright-Patterson AFB · 135K residents
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65
Jackson, MSHigh concern
Infrastructure crisis · 150K residents
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66
Savannah, GAHigh concern
Industrial PFAS from chemical plants · 145K residents
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67
Columbia, SCHigh concern
PFAS from Fort Jackson · 130K residents
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68
Fort Lauderdale, FLHigh concern
PFAS contamination · 180K residents
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69
Ann Arbor, MIHigh concern
PFAS from 3M/Gelman contamination · 120K residents
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70
Cary, NCHigh concern
GenX / PFAS contamination · 175K residents
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71
Peoria, AZHigh concern
Hard water / high TDS · 175K residents
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72
Tempe, AZHigh concern
Hard water / high TDS · 180K residents
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73
West Palm Beach, FLHigh concern
PFAS contamination · 115K residents
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74
Hartford, CTHigh concern
Lead from older infrastructure · 125K residents
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75
Stamford, CTHigh concern
PFAS contamination · 135K residents
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76
Modesto, CAHigh concern
1,2,3-TCP · 215K residents
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77
Glendale, CAHigh concern
Chromium-6 · 200K residents
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78
Brownsville, TXHigh concern
Rio Grande contamination · 190K residents
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79
McAllen, TXHigh concern
Rio Grande contamination · 143K residents
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80
Houston, TXMonitor
Disinfection byproducts (THMs) · 2.3M residents
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81
New York City, NYMonitor
Legacy lead service lines in older boroughs · 8.3M residents
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82
San Antonio, TXMonitor
Hard water / high mineral content · 1.5M residents
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83
Dallas, TXMonitor
Trihalomethanes (THMs) · 1.3M residents
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84
Denver, COMonitor
Lead service lines · 750K residents
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85
Boston, MAMonitor
Lead service lines in pre-1986 buildings · 675K residents
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86
Atlanta, GAMonitor
Disinfection byproducts · 500K residents
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87
Minneapolis, MNMonitor
Lead service lines · 430K residents
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88
Nashville, TNMonitor
Disinfection byproducts · 700K residents
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89
Indianapolis, INMonitor
Disinfection byproducts · 880K residents
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90
Columbus, OHMonitor
PFAS · 900K residents
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91
Omaha, NEMonitor
Nitrates from agriculture · 490K residents
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92
Kansas City, MOMonitor
Missouri River contamination · 500K residents
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93
Tampa, FLMonitor
PFAS contamination · 400K residents
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94
Sacramento, CAMonitor
Arsenic · 520K residents
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95
Jacksonville, FLMonitor
PFAS contamination · 950K residents
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96
Austin, TXMonitor
Disinfection byproducts · 960K residents
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97
Cincinnati, OHMonitor
Ohio River contamination · 310K residents
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98
Buffalo, NYMonitor
Lead service lines · 260K residents
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99
Anchorage, AKMonitor
PFAS from Elmendorf AFB · 290K residents
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100
Richmond, VAMonitor
James River contamination · 230K residents
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101
Fort Worth, TXMonitor
Trihalomethanes · 920K residents
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102
Oklahoma City, OKMonitor
Disinfection byproducts · 680K residents
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103
Wichita, KSMonitor
Atrazine from agriculture · 390K residents
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104
Arlington, TXMonitor
Disinfection byproducts · 390K residents
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105
Corpus Christi, TXMonitor
Disinfection byproducts · 320K residents
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106
Lexington, KYMonitor
Kentucky River contamination · 320K residents
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107
Plano, TXMonitor
Disinfection byproducts · 290K residents
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108
Orlando, FLMonitor
PFAS contamination · 310K residents
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109
Garland, TXMonitor
Disinfection byproducts · 240K residents
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110
Irving, TXMonitor
Disinfection byproducts · 240K residents
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111
Reno, NVMonitor
Hard water · 260K residents
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112
Fort Wayne, INMonitor
Agricultural nitrates · 265K residents
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113
St. Petersburg, FLMonitor
PFAS from military installations · 260K residents
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114
Boise, IDMonitor
Nitrates from agriculture · 240K residents
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115
Spokane, WAMonitor
PFAS from Fairchild AFB · 220K residents
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116
Little Rock, ARMonitor
Disinfection byproducts · 200K residents
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117
Worcester, MAMonitor
Lead in older building plumbing · 200K residents
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118
Knoxville, TNMonitor
TVA industrial legacy · 190K residents
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119
Providence, RIMonitor
Lead service lines · 180K residents
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120
Lincoln, NEMonitor
Nitrates from agriculture · 290K residents
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121
Cape Coral, FLMonitor
PFAS from military sites · 190K residents
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122
Tallahassee, FLMonitor
PFAS from military installations · 190K residents
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123
Fort Collins, COMonitor
Wildfire watershed contamination · 165K residents
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124
Sioux Falls, SDMonitor
Agricultural nitrates · 195K residents
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125
Fargo, NDMonitor
Nitrates from Red River Valley agriculture · 125K residents
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126
Provo, UTMonitor
PFAS from military sources · 116K residents
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127
Chattanooga, TNMonitor
Tennessee River industrial legacy · 180K residents
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128
Springfield, MOMonitor
Karst geology contamination risk · 165K residents
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129
Murfreesboro, TNMonitor
Stones River contamination · 140K residents
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130
Montgomery, ALMonitor
Disinfection byproducts · 200K residents
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131
Alexandria, VAMonitor
Lead from older infrastructure · 155K residents
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132
Lakewood, COMonitor
PFAS from Buckley SFB area · 155K residents
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133
Seattle, WAGenerally OK
Naturally soft / corrosive water · 750K residents
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134
San Francisco, CAGenerally OK
Chloramine disinfection byproducts · 870K residents
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135
Portland, ORGenerally OK
Naturally corrosive water · 650K residents
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Check your specific ZIP code
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