| TOWN OF LAKE ARTHUR WATER SYSTEM | LAKE ARTHUR, LA | 2,706 | 13 | Detected |
| UTILITIES INC- WHITEHALL/ HEAD OF ISLAND | MANDEVILLE, LA | 2,676 | 33 | — |
| PENDLETON WATER ASSOCIATION | MANY, LA | 2,634 | 1,060 | — |
| AVOYELLES WARD 3 WATERWORKS DISTRICT | MANSURA, LA | 2,619 | 6 | — |
| EVANGELINE WW DISTRICT 1 - PINE PRAIRIE | PINE PRAIRE, LA | 2,598 | 33 | — |
| PRAIRIE ROAD WATER DISTRICT | MONROE, LA | 2,598 | 312 | — |
| VILLAGE OF CANKTON WATER SYSTEM | CANKTON, LA | 2,598 | 67 | — |
| TOWN OF OLLA WATER SYSTEM | OLLA, LA | 2,565 | 140 | — |
| TOWN OF COLFAX | COLFAX, LA | 2,552 | 76 | — |
| TOWN OF WHITE CASTLE WATER SYSTEM | WHITE CASTLE, LA | 2,550 | 29 | — |
| TOWN OF ZWOLLE WATER SYSTEM | ZWOLLE, LA | 2,520 | 301 | — |
| START WATER SYSTEM | START, LA | 2,514 | 15 | — |
| ST TAM PARISH PINELAND PARK SUBD | COVINGTON, LA | 2,500 | 15 | — |
| EXXONMOBIL BATON ROUGE REFINERY | BATON ROUGE, LA | 2,500 | 3 | — |
| NORTH OAKS MEDICAL CENTER | HAMMOND, LA | 2,500 | 18 | — |
| DELTA DOWNS INC WATER SYSTEM | VINTON, LA | 2,481 | 39 | — |
| MAMOU ROAD WATER DISTRICT, INC | EUNICE, LA | 2,478 | 156 | — |
| TOWN OF GLENMORA WATER SYSTEM | GLENMORA, LA | 2,472 | 39 | — |
| NEBO WATER SYSTEM INC | HARRISONBURG, LA | 2,460 | 40 | — |
| TOWN OF DELCAMBRE WATER SYSTEM | DELCAMBRE, LA | 2,457 | 48 | — |
| LOGANSPORT WATER SYSTEM | LOGANSPORT, LA | 2,448 | 135 | — |
| TOWN OF ROSEPINE WATER SYSTEM | ROSEPINE, LA | 2,427 | 31 | — |
| HOLMESVILLE WATER SYSTEM | DOWNSVILLE, LA | 2,406 | 362 | — |
| POINTE COUPEE WWKS DISTRICT 2 - HWY 10 | NEW ROADS, LA | 2,401 | 18 | — |
| TOWN OF BASILE WATER SYSTEM | BASILE, LA | 2,400 | 245 | — |
| INNIS WATER CORPORATION INC | INNIS, LA | 2,400 | 16 | — |
| TOWN OF PLAIN DEALING WATER SYSTEM | PLAIN DEALING, LA | 2,346 | 475 | — |
| FAIRVIEW UNION WATER SYSTEM | COUSHATTA, LA | 2,346 | 1,589 | Clean |
| TE MAMOU WATER DISTRICT | VILLE PLATTE, LA | 2,319 | 50 | — |
| UTILITIES INC - FRENCH SETTLEMENT | MANDEVILLE, LA | 2,313 | 5 | — |
| DOGWOOD SOUTH WATER SYSTEM | BENTON, LA | 2,304 | 9 | — |
| TOWN OF ST FRANCISVILLE WATER SYSTEM | ST. FRANCISVILLE, LA | 2,304 | 20 | — |
| RINGGOLD WATER SYSTEM | RINGGOLD, LA | 2,283 | 122 | — |
| ST MARTIN WATER AND SEWER COMMISSION 1 | MORGAN CITY, LA | 2,262 | 95 | — |
| BLACK RIVER WATER SYSTEM | HARRISONBURG, LA | 2,256 | 48 | — |
| CENTRAL GRANT WATER SYSTEM | DRY PRONG, LA | 2,250 | 110 | — |
| UTILITIES INC - GREEN BRIER WATER SUPPLY | MANDEVILLE, LA | 2,250 | 36 | — |
| POINT WILHITE WS | DOWNSVILLE, LA | 2,235 | 405 | — |
| ASCENSION CONSOLIDATED UTILITY DIST 1 | DONALDSONVILLE, LA | 2,229 | 261 | — |
| TOWN OF EVERGREEN WATER SYSTEM | EVERGREEN, LA | 2,205 | 25 | — |
| KENTWOOD WATER SYSTEM | KENTWOOD, LA | 2,205 | 79 | — |
| TOWN OF DUSON WATER SYSTEM | DUSON, LA | 2,190 | 27 | — |
| PIONEER DARNELL WATER SYSTEM | PIONEER, LA | 2,190 | 21 | — |
| VILLAGE OF PALMETTO WATER SYSTEM | PALMETTO, LA | 2,178 | 199 | — |
| BETTER WATERWORKS WATER SYSTEM | WEST MONROE, LA | 2,160 | 331 | — |
| FORT POLK NORTH HOUSING WATER SYSTEM | FORT JOHNSON, LA | 2,155 | 7 | — |
| OIL CITY WATER WORKS | OIL CITY, LA | 2,148 | 1,085 | — |
| TOWN OF SIMMESPORT WATER SYSTEM | SIMMESPORT, LA | 2,142 | 36 | — |
| GULF STREAM MANOR WATER SYSTEM | LAKE CHARLES, LA | 2,130 | 210 | — |
| CALCASIEU PARISH WW 12 WARD 3 | LAKE CHARLES, LA | 2,130 | 4 | — |