Water Quality by County
3,254 counties with public water systems.
| County | State | Systems | Population | Violations |
|---|---|---|---|---|
| Karnes | Texas | 9 | 19,487 | 642 |
| Alpine | California | 40 | 19,460 | 265 |
| Washington | Alabama | 13 | 19,444 | 547 |
| Garrard | Kentucky | 2 | 19,379 | 382 |
| Rabun | Georgia | 38 | 19,361 | 2,069 |
| Clay | Iowa | 6 | 19,361 | 324 |
| La Salle Parish | Louisiana | 12 | 19,338 | 1,281 |
| Otero | Colorado | 23 | 19,329 | 8,576 |
| Bertie | North Carolina | 7 | 19,317 | 368 |
| Spencer | Indiana | 15 | 19,310 | 1,630 |
| Sagadahoc | Maine | 39 | 19,254 | 2,951 |
| Sabine | Texas | 13 | 19,246 | 1,426 |
| Lincoln | Wyoming | 44 | 19,227 | 2,914 |
| DeWitt | Texas | 12 | 19,157 | 787 |
| Polk | Arkansas | 17 | 19,139 | 788 |
| Cherokee | Kansas | 18 | 19,138 | 1,175 |
| Langlade | Wisconsin | 111 | 19,138 | 4,142 |
| Lincoln | Montana | 91 | 19,119 | 7,279 |
| Cassia | Idaho | 50 | 19,063 | 3,276 |
| Perry | Illinois | 10 | 19,045 | 450 |
| Benton | Iowa | 24 | 19,032 | 1,562 |
| Fayette | Illinois | 12 | 19,021 | 802 |
| Woodward | Oklahoma | 11 | 19,014 | 2,799 |
| Putnam | Ohio | 36 | 18,974 | 2,985 |
| Hale | Alabama | 4 | 18,957 | 206 |
| Randolph | Indiana | 45 | 18,952 | 2,700 |
| Russell | Virginia | 19 | 18,913 | 1,123 |
| Texas | Oklahoma | 21 | 18,887 | 4,947 |
| Curry | Oregon | 37 | 18,844 | 3,619 |
| Williamsburg | South Carolina | 15 | 18,842 | 330 |
| Camp | Texas | 8 | 18,816 | 301 |
| Lincoln | Wisconsin | 97 | 18,778 | 1,930 |
| Denali Borough | Alaska | 56 | 18,777 | 2,545 |
| Bremer | Iowa | 15 | 18,733 | 1,226 |
| Lee | Virginia | 15 | 18,733 | 840 |
| Roosevelt | New Mexico | 8 | 18,698 | 905 |
| Sumter | Georgia | 17 | 18,656 | 3,868 |
| Somerset | Maryland | 37 | 18,632 | 3,029 |
| Jo Daviess | Illinois | 49 | 18,628 | 2,305 |
| Crisp | Georgia | 20 | 18,550 | 1,257 |
| Douglas | Illinois | 16 | 18,548 | 574 |
| Lumpkin | Georgia | 48 | 18,513 | 1,135 |
| Livingston | Kentucky | 5 | 18,510 | 1,553 |
| Calhoun | Mississippi | 17 | 18,477 | 9,392 |
| Lincoln | Washington | 34 | 18,474 | 2,693 |
| Franklin | Texas | 4 | 18,457 | 146 |
| Amherst | Virginia | 15 | 18,426 | 917 |
| Bon Homme | South Dakota | 7 | 18,388 | 575 |
| Bond | Illinois | 16 | 18,346 | 1,200 |
| Louisa | Virginia | 40 | 18,333 | 2,117 |
| Nobles | Minnesota | 15 | 18,302 | 562 |
| Carbon | Wyoming | 26 | 18,284 | 1,289 |
| Mecklenburg | Virginia | 42 | 18,266 | 1,252 |
| Pike | Indiana | 6 | 18,263 | 612 |
| Bethel Census Area | Alaska | 57 | 18,253 | 35,961 |
| Washington | Nebraska | 22 | 18,240 | 770 |
| Greene | North Carolina | 8 | 18,212 | 1,798 |
| Hempstead | Arkansas | 13 | 18,181 | 936 |
| Northampton | North Carolina | 15 | 18,136 | 1,420 |
| Colorado | Texas | 46 | 18,134 | 3,320 |
| Choctaw | Alabama | 5 | 18,096 | 391 |
| Craig | Oklahoma | 10 | 18,083 | 2,974 |
| Gilmer | Georgia | 25 | 18,064 | 845 |
| County 09061 | 09 | 1 | 18,007 | 10 |
| Jackson Parish | Louisiana | 20 | 17,996 | 4,586 |
| Fannin | Georgia | 32 | 17,978 | 804 |
| Clay | Indiana | 15 | 17,977 | 863 |
| Crawford | Michigan | 97 | 17,965 | 2,061 |
| Logan | Colorado | 14 | 17,963 | 1,757 |
| Bates | Missouri | 15 | 17,912 | 1,187 |
| Gage | Nebraska | 25 | 17,901 | 1,344 |
| Osage | Kansas | 17 | 17,894 | 1,472 |
| Green | Kentucky | 2 | 17,893 | 216 |
| Jerome | Idaho | 24 | 17,778 | 1,336 |
| Buena Vista | Iowa | 12 | 17,687 | 417 |
| Plymouth | Iowa | 13 | 17,668 | 1,162 |
| Livingston | Missouri | 7 | 17,653 | 137 |
| Henry | Ohio | 23 | 17,641 | 2,210 |
| Lincoln | Oklahoma | 22 | 17,590 | 10,255 |
| Botetourt | Virginia | 53 | 17,570 | 2,320 |
| Humphreys | Tennessee | 17 | 17,545 | 1,676 |
| Vermillion | Indiana | 17 | 17,540 | 3,265 |
| Perry | Indiana | 6 | 17,527 | 528 |
| Hardee | Florida | 34 | 17,488 | 714 |
| Aguas Buenas Municipio | Puerto Rico | 10 | 17,468 | 4,240 |
| Westmoreland | Virginia | 48 | 17,463 | 928 |
| Nolan | Texas | 6 | 17,438 | 1,055 |
| Clarendon | South Carolina | 33 | 17,356 | 273 |
| Martin | North Carolina | 21 | 17,335 | 1,567 |
| Wabasha | Minnesota | 49 | 17,333 | 680 |
| Marquette | Wisconsin | 155 | 17,309 | 2,252 |
| Winn Parish | Louisiana | 13 | 17,302 | 7,046 |
| Crockett | Tennessee | 6 | 17,298 | 191 |
| Tate | Mississippi | 19 | 17,289 | 4,038 |
| Yadkin | North Carolina | 74 | 17,243 | 5,189 |
| Fillmore | Minnesota | 59 | 17,239 | 768 |
| Meeker | Minnesota | 57 | 17,222 | 242 |
| Chowan | North Carolina | 2 | 17,222 | 266 |
| Emanuel | Georgia | 20 | 17,186 | 1,807 |
| Menominee | Michigan | 46 | 17,177 | 2,865 |