Water quality by county
in Mississippi
EPA sampled public water systems across Mississippi for PFAS under its UCMR 5 programme. Of the 82 counties, 6 have a reading above a federal limit and 14 have not been sampled at all — which is not a clean result, only an absence of one. Each county below shows what was found, at what concentration, and at which utility.
| county | Population | Worst result | Compound |
|---|---|---|---|
| Lafayette County | 59,843 | 18× | PFOS · 72.2 ng/L |
| Alcorn County | 34,228 | 2.6× | PFOS · 10.6 ng/L |
| Marshall County | 34,374 | 2.4× | PFOS · 9.6 ng/L |
| Simpson County | 25,597 | 2.1× | PFOS · 8.6 ng/L |
| Harrison County | 213,730 | 1.9× | PFOS · 7.7 ng/L |
| Forrest County | 78,435 | 1.4× | PFOA · 5.5 ng/L |
| Adams County | 28,674 | under the limit | — |
| Amite County | 12,451 | not sampled | — |
| Attala County | 17,222 | under the limit | — |
| Benton County | 7,566 | not sampled | — |
| Bolivar County | 28,395 | under the limit | — |
| Calhoun County | 12,754 | under the limit | — |
| Carroll County | 9,378 | not sampled | — |
| Chickasaw County | 16,774 | under the limit | — |
| Choctaw County | 8,091 | not sampled | — |
| Claiborne County | 8,122 | under the limit | — |
| Clarke County | 15,155 | under the limit | — |
| Clay County | 18,213 | under the limit | — |
| Coahoma County | 20,105 | under the limit | — |
| Copiah County | 27,536 | under the limit | — |
| Covington County | 18,015 | under the limit | — |
| DeSoto County | 195,871 | under the limit | — |
| Franklin County | 7,516 | not sampled | — |
| George County | 25,880 | under the limit | — |
| Greene County | 13,675 | under the limit | — |
| Grenada County | 20,931 | under the limit | — |
| Hancock County | 46,492 | under the limit | — |
| Hinds County | 211,975 | under the limit | — |
| Holmes County | 15,560 | not sampled | — |
| Humphreys County | 7,121 | under the limit | — |
| Issaquena County | 1,295 | not sampled | — |
| Itawamba County | 24,198 | under the limit | — |
| Jackson County | 147,002 | under the limit | — |
| Jasper County | 15,799 | under the limit | — |
| Jefferson County | 6,900 | under the limit | — |
| Jefferson Davis County | 11,059 | not sampled | — |
| Jones County | 65,837 | under the limit | — |
| Kemper County | 8,562 | not sampled | — |
| Lamar County | 66,734 | under the limit | — |
| Lauderdale County | 70,588 | under the limit | — |
| Lawrence County | 11,672 | under the limit | — |
| Leake County | 21,462 | under the limit | — |
| Lee County | 83,012 | under the limit | — |
| Leflore County | 26,157 | under the limit | — |
| Lincoln County | 34,956 | under the limit | — |
| Lowndes County | 57,210 | under the limit | — |
| Madison County | 114,247 | under the limit | — |
| Marion County | 24,008 | under the limit | — |
| Monroe County | 33,483 | under the limit | — |
| Montgomery County | 9,411 | under the limit | — |
| Neshoba County | 28,973 | under the limit | — |
| Newton County | 21,063 | under the limit | — |
| Noxubee County | 9,825 | under the limit | — |
| Oktibbeha County | 51,965 | under the limit | — |
| Panola County | 32,764 | under the limit | — |
| Pearl River County | 59,030 | under the limit | — |
| Perry County | 11,406 | not sampled | — |
| Pike County | 38,980 | under the limit | — |
| Pontotoc County | 32,014 | under the limit | — |
| Prentiss County | 25,489 | under the limit | — |
| Quitman County | 5,542 | not sampled | — |
| Rankin County | 160,573 | under the limit | — |
| Scott County | 27,666 | under the limit | — |
| Sharkey County | 3,234 | not sampled | — |
| Smith County | 14,051 | not sampled | — |
| Stone County | 19,569 | under the limit | — |
| Sunflower County | 23,029 | under the limit | — |
| Tallahatchie County | 10,921 | under the limit | — |
| Tate County | 28,551 | under the limit | — |
| Tippah County | 21,423 | under the limit | — |
| Tishomingo County | 18,553 | under the limit | — |
| Tunica County | 9,157 | under the limit | — |
| Union County | 28,363 | under the limit | — |
| Walthall County | 13,839 | under the limit | — |
| Warren County | 42,105 | under the limit | — |
| Washington County | 41,181 | under the limit | — |
| Wayne County | 19,749 | under the limit | — |
| Webster County | 10,039 | under the limit | — |
| Wilkinson County | 7,820 | not sampled | — |
| Winston County | 17,418 | under the limit | — |
| Yalobusha County | 12,458 | under the limit | — |
| Yazoo County | 23,024 | under the limit | — |