Water Quality by County
3,254 counties with public water systems.
| County | State | Systems | Population | Violations |
|---|---|---|---|---|
| Walker | Georgia | 6 | 64,179 | 81 |
| Chaves | New Mexico | 15 | 64,059 | 1,075 |
| Warrick | Indiana | 10 | 63,888 | 682 |
| Windham | Connecticut | 255 | 63,884 | 21,628 |
| James City | Virginia | 28 | 63,764 | 1,310 |
| St. Mary Parish | Louisiana | 16 | 63,659 | 1,325 |
| County MP020 | Northern Mariana Islands | 48 | 63,273 | 3,534 |
| Riley | Kansas | 13 | 62,651 | 542 |
| La Plata | Colorado | 110 | 62,563 | 9,256 |
| Cayey Municipio | Puerto Rico | 9 | 62,427 | 1,815 |
| Cayuga | New York | 91 | 62,368 | 1,691 |
| Hardin | Texas | 28 | 62,319 | 2,862 |
| Garfield | Oklahoma | 22 | 62,290 | 3,615 |
| Gila | Arizona | 103 | 62,233 | 15,775 |
| Belmont | Ohio | 21 | 62,229 | 1,702 |
| Dubois | Indiana | 11 | 61,963 | 930 |
| Lenoir | North Carolina | 9 | 61,868 | 756 |
| Pender | North Carolina | 55 | 61,717 | 3,363 |
| St. Croix Island | US Virgin Islands | 131 | 61,668 | 878 |
| Lincoln | Oregon | 52 | 61,506 | 9,051 |
| Washington | Vermont | 127 | 61,446 | 15,111 |
| Garfield | Colorado | 86 | 61,334 | 7,428 |
| Hoke | North Carolina | 18 | 61,293 | 4,627 |
| Hall | Nebraska | 40 | 61,265 | 1,039 |
| Morgan | Indiana | 23 | 61,105 | 2,842 |
| Waller | Texas | 69 | 61,104 | 4,651 |
| Kosciusko | Indiana | 305 | 61,088 | 26,339 |
| Lawrence | Ohio | 6 | 61,075 | 281 |
| Washington | Ohio | 18 | 61,007 | 1,145 |
| Iron | Utah | 41 | 60,975 | 9,246 |
| Porter | Indiana | 83 | 60,757 | 6,413 |
| Lincoln Parish | Louisiana | 22 | 60,724 | 1,889 |
| Randolph | North Carolina | 95 | 60,461 | 12,811 |
| Christian | Missouri | 41 | 60,446 | 3,048 |
| Clay | Minnesota | 51 | 60,378 | 534 |
| Josephine | Oregon | 152 | 60,301 | 11,657 |
| Wagoner | Oklahoma | 13 | 60,271 | 4,331 |
| Acadia Parish | Louisiana | 13 | 59,922 | 724 |
| Kerr | Texas | 108 | 59,771 | 11,943 |
| Tolland | Connecticut | 293 | 59,720 | 17,053 |
| Steuben | New York | 152 | 59,707 | 10,478 |
| Blue Earth | Minnesota | 64 | 59,656 | 867 |
| Geary | Kansas | 16 | 59,609 | 997 |
| Laurens | South Carolina | 11 | 59,423 | 335 |
| Decatur | Iowa | 6 | 59,279 | 574 |
| County NV025 | Nevada | 4 | 59,225 | 719 |
| Lamar | Texas | 9 | 59,149 | 864 |
| Carter | Tennessee | 21 | 59,091 | 1,095 |
| Cherokee | Texas | 28 | 58,827 | 4,120 |
| Franklin | Massachusetts | 112 | 58,737 | 3,736 |
| Robertson | Tennessee | 4 | 58,643 | 298 |
| Klamath | Oregon | 108 | 58,638 | 8,722 |
| Wicomico | Maryland | 98 | 58,618 | 2,635 |
| Camden | Missouri | 235 | 58,552 | 13,676 |
| Wood | Wisconsin | 148 | 58,513 | 2,172 |
| Jefferson | Ohio | 35 | 58,488 | 1,923 |
| Vermilion | Illinois | 41 | 58,420 | 3,428 |
| Sherburne | Minnesota | 80 | 58,403 | 645 |
| Sarpy | Nebraska | 39 | 58,403 | 1,069 |
| Johnson | Missouri | 16 | 58,397 | 514 |
| Jefferson | Tennessee | 21 | 58,142 | 513 |
| Fajardo Municipio | Puerto Rico | 2 | 58,114 | 1,563 |
| Wayne | Indiana | 59 | 58,098 | 4,578 |
| Frederick | Virginia | 40 | 58,081 | 1,522 |
| Wilson | Texas | 18 | 58,064 | 516 |
| St. Thomas Island | US Virgin Islands | 112 | 58,003 | 416 |
| Grand Traverse | Michigan | 180 | 57,994 | 8,262 |
| Coles | Illinois | 16 | 57,953 | 520 |
| Van Buren | Michigan | 185 | 57,921 | 4,250 |
| Fremont | Colorado | 32 | 57,902 | 2,460 |
| Marion | West Virginia | 27 | 57,736 | 3,788 |
| Putnam | New York | 383 | 57,728 | 11,371 |
| Rockingham | North Carolina | 92 | 57,654 | 7,733 |
| Hopkins | Kentucky | 10 | 57,432 | 1,359 |
| Warren | Iowa | 12 | 57,255 | 571 |
| Crawford | Arkansas | 17 | 57,218 | 772 |
| Roscommon | Michigan | 231 | 57,124 | 6,018 |
| Marquette | Michigan | 95 | 57,092 | 2,172 |
| Clearfield | Pennsylvania | 37 | 56,946 | 6,349 |
| Hancock | Mississippi | 21 | 56,912 | 5,538 |
| Lee | North Carolina | 8 | 56,822 | 2,485 |
| Prince George's | Maryland | 38 | 56,734 | 1,362 |
| Chambers | Texas | 56 | 56,719 | 5,064 |
| Jessamine | Kentucky | 4 | 56,685 | 1,350 |
| Maverick | Texas | 2 | 56,600 | 559 |
| Jackson | Illinois | 24 | 56,580 | 761 |
| Calaveras | California | 52 | 56,388 | 1,548 |
| Greenwood | South Carolina | 17 | 56,330 | 265 |
| Montrose | Colorado | 26 | 56,323 | 3,807 |
| Grand | Colorado | 79 | 56,214 | 6,442 |
| Rusk | Texas | 35 | 56,180 | 2,614 |
| Warren | Mississippi | 7 | 56,140 | 1,489 |
| St. Croix | Wisconsin | 164 | 56,107 | 3,287 |
| Haywood | North Carolina | 59 | 56,075 | 5,284 |
| Cleburne | Arkansas | 8 | 55,790 | 183 |
| Rutherford | North Carolina | 60 | 55,778 | 6,972 |
| Wasatch | Utah | 59 | 55,668 | 8,761 |
| County NN001 | Navajo Nation | 51 | 55,505 | 9,921 |
| Pike | Kentucky | 3 | 55,418 | 918 |
| Crawford | Pennsylvania | 181 | 55,263 | 22,589 |