| LINVILLE-HAILE WATER SYSTEM | MARION, LA | 1,635 | 647 | — |
| UNION PARISH WATERWORKS DISTRICT 1 | FARMERVILLE, LA | 1,626 | 939 | — |
| CAMERON PARISH WW DISTRICT 11 - BIG LAKE | BELL CITY, LA | 1,620 | 18 | — |
| GREENBRIAR PRAIRIE BASSE WATER SYSTEM | SUNSET, LA | 1,620 | 73 | — |
| WARDS CHAPEL WATER SYSTEM | FARMERVILLE, LA | 1,620 | 510 | — |
| AMERICAN DREAM RV PARK WATER SYSTEM | ENGLEWOOD, LA | 1,605 | 6 | — |
| LIDDIEVILLE WATER SYSTEM | WINNSBORO, LA | 1,602 | 32 | — |
| EASTERN LOUISIANA MENTAL HEALTH SYSTEMS | JACKSON, LA | 1,600 | 101 | — |
| UTILITIES INC - WOODRIDGE SUBDIVISION | MANDEVILLE, LA | 1,590 | 6 | — |
| MAGNOLIA-GREEN ACRES SUBDIVISION | DES PERES, LA | 1,575 | 34 | — |
| MORROW WATER SYSTEM INC | MORROW, LA | 1,572 | 2 | — |
| CHENIERE DREW SOUTH WATER SYSTEM | WEST MONROE, LA | 1,563 | 68 | — |
| UTILITIES INC - QUAIL RIDGE SUBDIVISION | MANDEVILLE, LA | 1,563 | 13 | — |
| VILLAGE OF FOREST WATER SYSTEM | FOREST, LA | 1,560 | 11 | — |
| CHATHAM WATER SYSTEM | CHATHAM, LA | 1,557 | 635 | — |
| FROST TOWN WATER SYSTEM | CALHOUN, LA | 1,551 | 26 | — |
| GIL-GAL WATER SYSTEM | MINDEN, LA | 1,551 | 9 | — |
| DIVERSION WATER- WATER FRONT WEST | PRAIRIEVILLE, LA | 1,548 | 36 | — |
| TOWN OF CHENEYVILLE WATER SYSTEM | CHENEYVILLE, LA | 1,531 | 75 | — |
| VILLAGE OF HARRISONBURG WATER SYSTEM | HARRISONBURG, LA | 1,530 | 197 | — |
| HICO WATER SYSTEM | DUBACH, LA | 1,530 | 424 | — |
| TOWN OF LECOMPTE (LAWCO) | BATON ROUGE, LA | 1,527 | 4 | — |
| NORTH IBERVILLE WATER SYSTEM | PLAQUEMINE, LA | 1,524 | 13 | Detected |
| ROSELAND WATER SYSTEM | ROSELAND, LA | 1,521 | 118 | — |
| CAMPTI WATER SYSTEM | CAMPTI, LA | 1,515 | 93 | — |
| TOWN OF ELTON WATER SYSTEM | ELTON, LA | 1,512 | 119 | — |
| MARION WATER SYSTEM | MARION, LA | 1,512 | 518 | — |
| CAMERON PARISH WW DISTRICT 10 | JOHNSON BAYOU, LA | 1,509 | 7 | — |
| VILLAGE OF ANACOCO | ANACOCO, LA | 1,506 | 24 | — |
| SAREPTA WATER WORKS DISTRICT | SAREPTA, LA | 1,500 | 51 | — |
| KEITHVILLE ELEMENTARY AND MIDDLE SCHOOL | SHREVEPORT, LA | 1,500 | 41 | — |
| EXXONMOBIL BATON ROUGE CHEMICAL PLANT | BATON ROUGE, LA | 1,500 | 18 | — |
| SHONGALOO WATER SYSTEM | SHONGALOO, LA | 1,485 | 20 | — |
| ILE DES CANNES WATER SYSTEM | DUSON, LA | 1,476 | 2 | — |
| HILLY-GREENWOOD WATER SYSTEM | RUSTON, LA | 1,476 | 20 | — |
| GRAYSON WATER SYSTEM | GRAYSON, LA | 1,461 | 75 | — |
| EAST DESOTO WATER SYSTEM | MANSFIELD, LA | 1,455 | 365 | — |
| LPWDN LA NEUVILLE HOLIDAY SUBDIVISION WS | LAFAYETTE, LA | 1,455 | 0 | — |
| DIXIE OVERLAND WATER SYSTEM | MINDEN, LA | 1,455 | 47 | — |
| SOUTH OAKDALE WATER SYSTEM | OAKDALE, LA | 1,434 | 20 | — |
| SUMMERVILLE WATER SYSTEM | JENA, LA | 1,425 | 23 | Clean |
| WARD 6 WATER ASSOCIATION OF RAPIDES | GLENMORA, LA | 1,410 | 32 | — |
| GERMANTOWN WATER SYSTEM | MINDEN, LA | 1,410 | 62 | — |
| SARDIS WATER SYSTEM | GILBERT, LA | 1,404 | 707 | — |
| BASF CORPORATION | GEISMAR, LA | 1,391 | 25 | — |
| FORDOCHE, TOWN OF | FORDOCHE, LA | 1,380 | 15 | — |
| COTTON VALLEY WATER SYSTEM | COTTON VALLEY, LA | 1,380 | 252 | — |
| BAYOU PIERRE WATER SYSTEM | COUSHATTA, LA | 1,371 | 104 | — |
| DIVERSION WATER RIVER HIGHLANDS | PRAIRIEVILLE, LA | 1,356 | 22 | — |
| MAGNOLIA-MONTEREY SUBDIVISION | DES PERES, LA | 1,356 | 39 | — |