Water Quality by County
3,254 counties with public water systems.
| County | State | Systems | Population | Violations |
|---|---|---|---|---|
| St. Francois | Missouri | 43 | 55,207 | 5,269 |
| Camden | Georgia | 17 | 55,104 | 1,000 |
| Van Zandt | Texas | 23 | 55,045 | 2,116 |
| Douglas | Nevada | 38 | 54,913 | 5,162 |
| Pearl River | Mississippi | 19 | 54,819 | 6,507 |
| Wayne | Pennsylvania | 226 | 54,750 | 46,273 |
| Livingston | New York | 51 | 54,699 | 2,501 |
| Troup | Georgia | 16 | 54,586 | 424 |
| Cherokee | South Carolina | 8 | 54,307 | 164 |
| Indiana | Pennsylvania | 53 | 54,205 | 8,482 |
| Platte | Missouri | 20 | 54,031 | 659 |
| Gordon | Georgia | 3 | 53,934 | 157 |
| Curry | New Mexico | 16 | 53,914 | 2,893 |
| McMinn | Tennessee | 11 | 53,724 | 517 |
| Polk | Oregon | 29 | 53,707 | 2,619 |
| Monroe | Tennessee | 13 | 53,603 | 1,012 |
| Webster Parish | Louisiana | 35 | 53,565 | 2,493 |
| Pitkin | Colorado | 50 | 53,372 | 6,062 |
| Shelby | Kentucky | 4 | 53,306 | 267 |
| Sweetwater | Wyoming | 47 | 53,285 | 1,717 |
| Franklin | Tennessee | 9 | 53,019 | 864 |
| St. Charles Parish | Louisiana | 1 | 52,879 | 9 |
| Avoyelles Parish | Louisiana | 17 | 52,812 | 674 |
| Grant | Indiana | 47 | 52,670 | 3,905 |
| Marion | Ohio | 33 | 52,490 | 1,445 |
| Effingham | Georgia | 83 | 52,235 | 2,658 |
| Grundy | Illinois | 63 | 52,209 | 12,515 |
| Chippewa | Wisconsin | 219 | 52,060 | 3,638 |
| Tehama | California | 111 | 52,035 | 1,111 |
| Valencia | New Mexico | 30 | 51,956 | 8,331 |
| Elko | Nevada | 44 | 51,925 | 3,094 |
| Rockingham | Virginia | 64 | 51,886 | 1,187 |
| Campbell | Wyoming | 68 | 51,714 | 2,720 |
| Nelson | Kentucky | 4 | 51,678 | 659 |
| Kittitas | Washington | 104 | 51,670 | 3,250 |
| Vega Baja Municipio | Puerto Rico | 9 | 51,647 | 1,557 |
| Beaufort | North Carolina | 14 | 51,566 | 892 |
| Saline | Kansas | 13 | 51,554 | 833 |
| Coos | Oregon | 47 | 51,546 | 6,822 |
| Rhea | Tennessee | 7 | 51,475 | 556 |
| Winona | Minnesota | 79 | 51,377 | 1,204 |
| Henderson | Kentucky | 6 | 51,331 | 1,467 |
| Lyon | Nevada | 30 | 51,309 | 4,095 |
| Hill | Texas | 39 | 50,941 | 2,755 |
| Dare | North Carolina | 15 | 50,811 | 1,005 |
| Pittsburg | Oklahoma | 22 | 50,811 | 9,873 |
| Reno | Kansas | 25 | 50,620 | 2,663 |
| Routt | Colorado | 50 | 50,449 | 5,239 |
| Portage | Wisconsin | 150 | 50,413 | 2,795 |
| Madison | Idaho | 33 | 50,343 | 998 |
| Wilkes | North Carolina | 89 | 50,297 | 3,289 |
| Chilton | Alabama | 5 | 50,244 | 211 |
| Cortland | New York | 79 | 50,045 | 7,338 |
| Beauregard Parish | Louisiana | 9 | 50,035 | 303 |
| Santa Cruz | Arizona | 37 | 49,946 | 6,256 |
| Stanly | North Carolina | 29 | 49,920 | 2,874 |
| St. Joseph | Michigan | 135 | 49,903 | 3,930 |
| Summit | Utah | 78 | 49,848 | 9,896 |
| Pottawatomie | Oklahoma | 27 | 49,766 | 18,870 |
| Lapeer | Michigan | 244 | 49,673 | 6,205 |
| Inyo | California | 111 | 49,669 | 1,965 |
| Knox | Illinois | 45 | 49,636 | 2,317 |
| Chatham | North Carolina | 45 | 49,625 | 8,155 |
| Hawkins | Tennessee | 12 | 49,573 | 1,159 |
| Bristol | Rhode Island | 4 | 49,495 | 330 |
| Montcalm | Michigan | 162 | 49,446 | 6,429 |
| Isabela Municipio | Puerto Rico | 1 | 49,419 | 522 |
| Isabella | Michigan | 90 | 49,206 | 2,991 |
| Herkimer | New York | 125 | 49,044 | 13,517 |
| Villalba Municipio | Puerto Rico | 14 | 49,031 | 7,861 |
| Bedford | Virginia | 56 | 48,941 | 2,918 |
| Lawrence | Tennessee | 13 | 48,706 | 962 |
| Butler | Kansas | 21 | 48,500 | 1,552 |
| Oldham | Kentucky | 2 | 48,476 | 40 |
| Ionia | Michigan | 129 | 48,474 | 2,651 |
| Watauga | North Carolina | 97 | 48,240 | 7,254 |
| Washington | Virginia | 8 | 48,197 | 201 |
| Fauquier | Virginia | 70 | 48,116 | 3,782 |
| Prince George | Virginia | 28 | 47,944 | 2,146 |
| Richmond | North Carolina | 9 | 47,832 | 705 |
| St. John the Baptist Parish | Louisiana | 12 | 47,793 | 1,210 |
| Franklin | North Carolina | 73 | 47,692 | 9,785 |
| Carter | Oklahoma | 8 | 47,657 | 3,630 |
| Brown | Ohio | 7 | 47,554 | 802 |
| Armstrong | Pennsylvania | 42 | 47,549 | 4,905 |
| Greene | New York | 196 | 47,534 | 16,600 |
| Lajas Municipio | Puerto Rico | 1 | 47,531 | 337 |
| Washington | Mississippi | 14 | 47,415 | 6,121 |
| Seneca | Ohio | 64 | 47,390 | 5,533 |
| Eastern District | American Samoa | 9 | 47,380 | 1,116 |
| Le Flore | Oklahoma | 21 | 47,285 | 5,202 |
| Finney | Kansas | 18 | 47,281 | 1,522 |
| Barry | Michigan | 192 | 47,248 | 5,993 |
| Stone | Missouri | 242 | 47,185 | 18,773 |
| County 09017 | 09 | 18 | 47,180 | 4,330 |
| Kenai Peninsula Borough | Alaska | 201 | 47,039 | 23,648 |
| Crittenden | Arkansas | 15 | 47,011 | 767 |
| Hancock | Maine | 201 | 46,973 | 21,298 |
| Covington | Alabama | 11 | 46,951 | 543 |
| Dearborn | Indiana | 10 | 46,909 | 431 |