EPA UCMR 5 results for 268 public water systems. 48 had at least one PFAS detected; 7 had a highest single PFOA or PFOS result above 4.0 ppt.
UCMR 5 is a one-time EPA monitoring program, not a compliance determination. The values shown are the highest single sample result at any of the system's sampling points; one result above 4.0 ppt does not mean the system violates the PFAS rule, which is judged on running annual averages under separate compliance monitoring. Results describe the public water system, not an individual home.
| Water system | Serves | PFOA max (ppt) | PFOS max (ppt) | PFAS detected |
|---|---|---|---|---|
| Abita Springs Water System LA1103002 | St. Tammany Parish County | ND | ND | 0 |
| Arcadia Water System LA1013003 | Bienville Parish County | ND | ND | 0 |
| Archibald Water System LA1083012 | Richland Parish County | ND | ND | 0 |
| Assumption Parish WW District 1 LA1007001 | Assumption Parish County | ND | ND | 2 |
| Avoyelles Parish Waterworks District 1 LA1009002 | Avoyelles Parish County | ND | ND | 0 |
| Avoyelles Ward One Water System Inc LA1009016 | Avoyelles Parish County | ND | ND | 0 |
| Barksdale AFB Water System LA1015022 | Bossier Parish County | ND | ND | 0 |
| Bastrop Water System LA1067003 | Morehouse Parish County | ND | ND | 0 |
| Baton Rouge Water Company LA1033005 | East Baton Rouge Parish County | ND | ND | 0 |
| Bayou Des Cannes Water System LA1039016 | Evangeline Parish County | ND | ND | 0 |
| Bayou Liberty Water Association LA1103005 | St. Tammany Parish County | ND | ND | 0 |
| Bayou Teche Water Works LA1099002 | St. Martin Parish County | ND | ND | 0 |
| Beau Chene Water System LA1103006 | St. Tammany Parish County | ND | ND | 0 |
| Beauregard District No 2 Ward No 5 LA1011012 | Beauregard Parish County | ND | ND | 0 |
| Beauregard Water Works Dist #3 LA1011008 | Beauregard Parish County | ND | ND | 0 |
| Belle Chasse Water District LA1075001 | Plaquemines Parish County | ND | ND | 1 |
| Blanchard Water System LA1017006 | Caddo Parish County | ND | ND | 0 |
| Bogue-Lusa Water Works District LA1117009 | Washington Parish County | ND | ND | 0 |
| Brouillette Water System Inc LA1009003 | Avoyelles Parish County | ND | ND | 0 |
| Brownville Water System LA1073004 | Ouachita Parish County | ND | ND | 0 |
| Buckeye Water District 50 LA1079004 | Rapides Parish County | ND | ND | 0 |
| Cadeville Water District LA1073060 | Ouachita Parish County | ND | ND | 0 |
| Calcasieu Parish WW Dist 9 Carlyss LA1019116 | Calcasieu Parish County | ND | ND | 0 |
| Calcasieu Parish WW District 7 LA1019114 | Calcasieu Parish County | ND | ND | 0 |
| Calcasieu Parish WW District 8 LA1019118 | Calcasieu Parish County | ND | ND | 0 |
| Calcasieu Parish WW District No 1 LA1019051 | Calcasieu Parish County | ND | ND | 0 |
| Calcasieu Parish WW District No 4 LA1019053 | Calcasieu Parish County | ND | ND | 0 |
| Calcasieu Parish WW District No 5 LA1019084 | Calcasieu Parish County | ND | ND | 0 |
| Calhoun Water System LA1073006 | Ouachita Parish County | ND | ND | 0 |
| Cameron Parish WW District 11-Sweet Lake LA1023011 | Cameron Parish County | ND | ND | 0 |
| Cameron Parish WW District 9 LA1023012 | Cameron Parish County | ND | ND | 0 |
| Cecilia Water Corporation LA1099005 | St. Martin Parish County | ND | ND | 0 |
| Chataignier Water System LA1039002 | Evangeline Parish County | ND | ND | 0 |
| Cheniere Drew North Water System LA1073100 | Ouachita Parish County | ND | ND | 0 |
| City of Abbeville Water System LA1113001 | Vermilion Parish County | ND | ND | 1 |
| City of Alexandria Water System LA1079001 | Rapides Parish County | ND | ND | 0 |
| City of Baker Water System LA1033003 | East Baton Rouge Parish County | ND | ND | 0 |
| City of Bogalusa Water System LA1117001 | Washington Parish County | ND | ND | 0 |
| City of Bossier City Water System LA1015004 | Bossier Parish County | ND | ND | 0 |
| City of Breaux Bridge Water System LA1099003 | St. Martin Parish County | ND | ND | 0 |
| City of Broussard Water System LA1055003 | Lafayette Parish County | ND | ND | 0 |
| City of Carencro Water System LA1055005 | Lafayette Parish County | ND | ND | 0 |
| City of Denham Springs Water System LA1063004 | Livingston Parish County | ND | ND | 0 |
| City of Deridder Water System LA1011001 | Beauregard Parish County | ND | ND | 0 |
| City of Gonzales Water System LA1005030 | Ascension Parish County | ND | ND | 0 |
| City of Hammond Water System LA1105009 | Tangipahoa Parish County | ND | ND | 0 |
| City of Jeanerette Water System LA1045004 | Iberia Parish County | ND | ND | 1 |
| City of Jennings Water System LA1053003 | Jefferson Davis Parish County | ND | ND | 0 |
| City of Kaplan Water System LA1113009 | Vermilion Parish County | ND | ND | 0 |
| City of Lake Charles Water System LA1019029 | Calcasieu Parish County | ND | ND | 0 |
| City of Leesville Water System LA1115019 | Vernon Parish County | ND | ND | 0 |
| City of Many Water System LA1085016 | Sabine Parish County | ND | ND | 1 |
| City of Marksville Water System LA1009011 | Avoyelles Parish County | ND | ND | 0 |
| City of Oakdale Water System LA1003006 | Allen Parish County | ND | ND | 0 |
| City of Opelousas Water System LA1097010 | St. Landry Parish County | ND | ND | 0 |
| City of Pineville Water System LA1079016 | Rapides Parish County | ND | ND | 0 |
| City of Plaquemine Water System LA1047005 | Iberville Parish County | 6.2 | 6 | 5 |
| City of Rayne Water System LA1001007 | Acadia Parish County | ND | ND | 0 |
| City of Scott Water System LA1055026 | Lafayette Parish County | ND | ND | 0 |
| City of St Martinville Water System LA1099007 | St. Martin Parish County | ND | ND | 0 |
| City of Vidalia Water System LA1029011 | Concordia Parish County | 20.1 | 8.5 | 8 |
| City of Ville Platte Water System LA1039010 | Evangeline Parish County | ND | ND | 0 |
| City of Winnfield Water System LA1127012 | Winn Parish County | ND | ND | 0 |
| City of Youngsville Purchase WS LA1055195 | Lafayette Parish County | ND | ND | 0 |
| Concordia Waterworks District 1 LA1029003 | Concordia Parish County | ND | ND | 0 |
| Consolidated Waterworks District 2 LA1067012 | Morehouse Parish County | ND | ND | 0 |
| Coushatta Water System LA1081001 | Red River Parish County | ND | ND | 0 |
| Covington Water Supply LA1103011 | St. Tammany Parish County | ND | ND | 0 |
| Crowley Water System (Lawco) LA1001002 | Acadia Parish County | ND | ND | 0 |
| Culbertson Water System LA1061024 | Lincoln Parish County | ND | ND | 0 |
| Cypress Black Bayou Water System LA1015040 | Bossier Parish County | ND | ND | 0 |
| Delhi Water Supply LA1083002 | Richland Parish County | ND | ND | 0 |
| Deltech Corporation LA2033025 | East Baton Rouge Parish County | ND | ND | 0 |
| Dequincy Water System (Lawco) LA1019008 | Calcasieu Parish County | ND | ND | 0 |
| Desoto Parish Water Works District 1 LA1031030 | De Soto Parish County | ND | ND | 2 |
| Dow USA, La Division LA2047003 | Iberville Parish County | ND | ND | 0 |
| Doyline Waterworks District 1 LA1119008 | Webster Parish County | ND | ND | 0 |
| Dubach Water System LA1061003 | Lincoln Parish County | ND | ND | 0 |
| E Jefferson WW District 1 LA1051001 | Jefferson Parish County | ND | ND | 1 |
| East Carroll WS South LA1035007 | East Carroll Parish County | ND | ND | 0 |
| East Central Vernon Water System LA1115117 | Vernon Parish County | ND | ND | 0 |
| East Feliciana Rural Gurley Rd WS LA1037004 | East Feliciana Parish County | ND | ND | 0 |
| East Side Water System LA1039003 | Evangeline Parish County | ND | ND | 0 |
| Ebarb WWKS Dist # 1 - Aimwell Area LA1085059 | Sabine Parish County | ND | ND | 0 |
| Egan Water Corporation LA1001025 | Acadia Parish County | ND | ND | 0 |
| Eunice Water System (Lawco) LA1097022 | St. Landry Parish County | ND | ND | 0 |
| FSWC - Hammond Heights LA1105010 | Tangipahoa Parish County | ND | ND | 0 |
| Fairview Union Water System LA1081012 | Red River Parish County | ND | ND | 0 |
| False River Water Company LA1077041 | Pointe Coupee Parish County | ND | ND | 0 |
| Farmerville Water System LA1111005 | Union Parish County | ND | ND | 2 |
| Fifth Ward Water System LA1009007 | Avoyelles Parish County | ND | ND | 0 |
| Folsom Water Supply LA1103014 | St. Tammany Parish County | ND | ND | 0 |
| Forest Hill Utilities LA1079009 | Rapides Parish County | ND | ND | 0 |
| Fort Polk North Water System LA1115064 | Vernon Parish County | ND | ND | 0 |
| Fort Polk South Water System LA1115065 | Vernon Parish County | ND | ND | 0 |
| Franklin Water Supply LA1101003 | St. Mary Parish County | ND | ND | 1 |
| Gardner Community Water System LA1079010 | Rapides Parish County | ND | ND | 0 |
| Gillis Long Center LA1047008 | Iberville Parish County | ND | ND | 0 |
| Gowc East LA1073121 | Ouachita Parish County | ND | ND | 0 |
| Gowc North Water System LA1073120 | Ouachita Parish County | ND | ND | 0 |
| Grambling State University WS LA1061005 | Lincoln Parish County | ND | ND | 0 |
| Grambling Water System LA1061006 | Lincoln Parish County | ND | ND | 0 |
| Gramercy Waterworks LA1093002 | St. James Parish County | ND | ND | 1 |
| Greater Ward 1 Waterworks District LA1061007 | Lincoln Parish County | ND | ND | 0 |
| Greensburg Water System LA1091004 | St. Helena Parish County | ND | ND | 0 |
| Gretna Waterworks LA1051003 | Jefferson Parish County | ND | ND | 1 |
| Henderson Nina Water System Inc LA1099006 | St. Martin Parish County | ND | ND | 0 |
| Homer Water System, La LA1027003 | Claiborne Parish County | ND | ND | 0 |
| Houma Water Treatment Service Area LA1109001 | Terrebonne Parish County | ND | ND | 2 |
| Houston River Waterworks District 11 LA1019119 | Calcasieu Parish County | ND | ND | 0 |
| Iberia Water Works District 3 - Coteau LA1045002 | Iberia Parish County | ND | ND | 0 |
| Iberville Waterworks District #2 LA1047007 | Iberville Parish County | ND | ND | 0 |
| Intracoastal Water System West LA1047002 | Iberville Parish County | ND | ND | 1 |
| Jeff Davis Central Waterworks District LA1053012 | Jefferson Davis Parish County | ND | ND | 0 |
| Jeff Davis Water District 4 LA1053013 | Jefferson Davis Parish County | ND | ND | 0 |
| Jeff Davis Water and Sewer Commission 1 LA1053014 | Jefferson Davis Parish County | ND | ND | 0 |
| Jonesboro Water System, La LA1049010 | Jackson Parish County | ND | ND | 0 |
| Keatchie Water System LA1031007 | De Soto Parish County | ND | ND | 0 |
| Kiroli Darbonne WS LA1073020 | Ouachita Parish County | ND | ND | 0 |
| Kolin Ruby Wise Waterwork District 11 A LA1079023 | Rapides Parish County | ND | ND | 0 |
| LPWD North Production Facility LA1055171 | Lafayette Parish County | ND | ND | 0 |
| LPWD South LA1055156 | Lafayette Parish County | ND | ND | 0 |
| Lafayette Utilities Water System LA1055017 | Lafayette Parish County | ND | ND | 0 |
| Lafourche Water District 1 LA1057001 | Lafourche Parish County | ND | ND | 1 |
| Lake Providence Water System LA1035002 | East Carroll Parish County | ND | ND | 0 |
| Lawtell Water Works District No 1 LA1097004 | St. Landry Parish County | ND | ND | 0 |
| Lee Road Water Corporation LA1103020 | St. Tammany Parish County | ND | ND | 0 |
| Lena Water System Inc LA1079019 | Rapides Parish County | ND | ND | 0 |
| Lewisburg Bellevue Water System LA1097006 | St. Landry Parish County | ND | ND | 0 |
| Louisiana State Penitentiary LA1125005 | West Feliciana Parish County | ND | ND | 0 |
| Lpwdn North Region LA1055191 | Lafayette Parish County | ND | ND | 0 |
| Lutcher Waterworks LA1093003 | St. James Parish County | ND | ND | 1 |
| Magnolia Plantation Water System Inc LA1113032 | Vermilion Parish County | ND | ND | 0 |
| Magnolia Water Utilities - Eden Isles LA1103013 | St. Tammany Parish County | ND | ND | 0 |
| Magnolia Water Utilities - Greenleaves LA1103118 | St. Tammany Parish County | ND | ND | 0 |
| Magnolia Water Utilities - the Meadows LA1103106 | St. Tammany Parish County | ND | ND | 0 |
| Mandeville Water Supply LA1103023 | St. Tammany Parish County | ND | ND | 0 |
| Mansfield Water System LA1031009 | De Soto Parish County | ND | ND | 1 |
| Milton Purchase Water System LA1055196 | Lafayette Parish County | ND | ND | 0 |
| Minden Water System LA1119021 | Webster Parish County | ND | ND | 0 |
| Mire Branch Water Corporation LA1001024 | Acadia Parish County | ND | ND | 0 |
| Monroe Water System, La LA1073031 | Ouachita Parish County | ND | ND | 1 |
| Monterey Rural Water System Inc LA1029007 | Concordia Parish County | ND | ND | 0 |
| Morgan City Water System, La LA1101005 | St. Mary Parish County | ND | ND | 0 |
| Natchitoches Parish WWKS District 2 LA1069006 | Natchitoches Parish County | ND | ND | 0 |
| Natchitoches Water System LA1069007 | Natchitoches Parish County | ND | ND | 1 |
| New Carroll Water System LA1123005 | West Carroll Parish County | ND | ND | 0 |
| New Iberia Water System (Lawco) LA1045009 | Iberia Parish County | ND | ND | 0 |
| New Llano Water Department LA1115022 | Vernon Parish County | ND | ND | 0 |
| New Orleans Algiers Water Works LA1071001 | Orleans Parish County | 4 | 4.5 | 3 |
| New Orleans Carrollton WW LA1071009 | Orleans Parish County | 4.1 | 4.2 | 6 |
| New Roads Water System LA1077026 | Pointe Coupee Parish County | ND | ND | 0 |
| North Desoto Water System LA1031011 | De Soto Parish County | ND | ND | 0 |
| North Franklin Water Works LA1041003 | Franklin Parish County | ND | ND | 0 |
| North Iberville Water System LA1047024 | Iberville Parish County | ND | ND | 0 |
| North of Crowley Water Corporation LA1001023 | Acadia Parish County | ND | ND | 0 |
| Parish Utilities of Ascension LA1005035 | Ascension Parish County | ND | 4.5 | 3 |
| Patterson Water System LA1101006 | St. Mary Parish County | ND | ND | 2 |
| Pinehill Waterworks District LA1017027 | Caddo Parish County | ND | ND | 1 |
| Plaisance Water System LA1097012 | St. Landry Parish County | ND | ND | 0 |
| Pleasant Valley Water System LA1119023 | Webster Parish County | ND | ND | 0 |
| Pointe Coupee Water Works District 1 LA1077043 | Pointe Coupee Parish County | ND | ND | 1 |
| Pollock Area Water System Inc LA1043017 | Grant Parish County | ND | ND | 0 |
| Pontchatoula Water System LA1105019 | Tangipahoa Parish County | ND | ND | 0 |
| Port Allen Water System LA1121014 | West Baton Rouge Parish County | ND | ND | 0 |
| Port Sulphur Water District LA1075006 | Plaquemines Parish County | ND | 4.6 | 2 |
| Prairie Ronde Water System Inc LA1097014 | St. Landry Parish County | ND | ND | 0 |
| Rapides Island Water Association Inc LA1079020 | Rapides Parish County | ND | ND | 0 |
| Rapides Parish Waterworks District 3 LA1079017 | Rapides Parish County | ND | ND | 0 |
| Rayville Water System LA1083006 | Richland Parish County | ND | ND | 1 |
| Resolve Whisperwood Estates SD WS LA1103046 | St. Tammany Parish County | ND | ND | 0 |
| Rural Franklinton Water LA1117003 | Washington Parish County | ND | ND | 0 |
| Ruston Water System LA1061017 | Lincoln Parish County | ND | ND | 0 |
| Sabine Parish Water District 1 LA1085036 | Sabine Parish County | ND | ND | 0 |
| Savoy Swords Water System Inc LA1097024 | St. Landry Parish County | ND | ND | 0 |
| Schriever Water Treatment Service Area LA1109002 | Terrebonne Parish County | ND | ND | 2 |
| Shreveport Water System LA1017031 | Caddo Parish County | ND | ND | 1 |
| Slidell Water Supply LA1103041 | St. Tammany Parish County | ND | ND | 0 |
| South Claiborne Water System LA1027006 | Claiborne Parish County | ND | ND | 0 |
| South Grant Water Corporation LA1043008 | Grant Parish County | ND | ND | 0 |
| South Monroe WS Gowc LA1073046 | Ouachita Parish County | ND | ND | 0 |
| South Rayne Water Corporation LA1001022 | Acadia Parish County | ND | ND | 0 |
| South Toledo Bend Water District LA1085055 | Sabine Parish County | ND | ND | 1 |
| South Vernon Parish Waterworks District LA1115118 | Vernon Parish County | ND | ND | 0 |
| Southeast Waterworks District 2 LA1113031 | Vermilion Parish County | ND | ND | 0 |
| Southwest Allen WW District No 2 LA1003009 | Allen Parish County | ND | ND | 1 |
| Southwest Ouachita Waterworks, Inc LA1073047 | Ouachita Parish County | ND | ND | 0 |
| Springhill Water System LA1119028 | Webster Parish County | ND | ND | 0 |
| St Bernard Parish Waterworks LA1087001 | St. Bernard Parish County | ND | ND | 0 |
| St Charles Parish Dept of Waterworks LA1089001 | St. Charles Parish County | ND | ND | 1 |
| St James Water District 1 LA1093004 | St. James Parish County | ND | ND | 0 |
| St James Water District 2 LA1093005 | St. James Parish County | ND | ND | 1 |
| St John Water District 1 LA1095003 | St. John the Baptist Parish County | ND | ND | 1 |
| St John Water District 2 LA1095002 | St. John the Baptist Parish County | ND | ND | 2 |
| St John Water District 3 LA1095007 | St. John the Baptist Parish County | ND | ND | 0 |
| St Landry Water Works District 2 Rural LA1097033 | St. Landry Parish County | ND | ND | 0 |
| St Mary Parish W&S #2 Bayou Vista LA1101015 | St. Mary Parish County | ND | ND | 3 |
| St Mary Water & Sewer Comm #3 LA1101010 | St. Mary Parish County | ND | ND | 1 |
| St Tam Parish - Briarwood Terrace LA1103079 | St. Tammany Parish County | ND | ND | 0 |
| St Tam Parish - Cross Gates SD LA1103053 | St. Tammany Parish County | ND | ND | 1 |
| St Tam Parish-Faubourg-Coquille LA1103149 | St. Tammany Parish County | ND | ND | 0 |
| St Tammany Water Dist 2 LA1103033 | St. Tammany Parish County | ND | ND | 0 |
| Sulphur City of Water System LA1019044 | Calcasieu Parish County | ND | ND | 0 |
| Summerville Water System LA1059009 | La Salle Parish County | ND | ND | 0 |
| Tallulah Water System LA1065003 | Madison Parish County | ND | ND | 0 |
| Tangipahoa (Second Ward) Water District LA1105077 | Tangipahoa Parish County | ND | ND | 0 |
| Tangipahoa Parish Water District LA1105008 | Tangipahoa Parish County | ND | ND | 0 |
| Tensas Water District Association LA1107009 | Tensas Parish County | ND | ND | 1 |
| Tesi Ossun Heights LA1055140 | Lafayette Parish County | ND | ND | 0 |
| Thibodaux Waterworks LA1057003 | Lafourche Parish County | ND | ND | 0 |
| Town & Country Service LA1073054 | Ouachita Parish County | ND | ND | 1 |
| Town of Albany Water System LA1063022 | Livingston Parish County | ND | ND | 0 |
| Town of Amite Water System LA1105001 | Tangipahoa Parish County | ND | ND | 0 |
| Town of Arnaudville Water System LA1099001 | St. Martin Parish County | ND | ND | 0 |
| Town of Benton Water System LA1015002 | Bossier Parish County | ND | ND | 1 |
| Town of Berwick LA1101014 | St. Mary Parish County | ND | ND | 1 |
| Town of Bunkie Water System LA1009004 | Avoyelles Parish County | ND | ND | 0 |
| Town of Church Point Water System LA1001001 | Acadia Parish County | ND | ND | 0 |
| Town of Erath Water System LA1113005 | Vermilion Parish County | ND | ND | 0 |
| Town of Ferriday Water System LA1029005 | Concordia Parish County | ND | ND | 0 |
| Town of Franklinton Water System LA1117002 | Washington Parish County | ND | ND | 0 |
| Town of Greenwood Water System LA1017014 | Caddo Parish County | ND | ND | 1 |
| Town of Haughton Water System LA1015011 | Bossier Parish County | ND | ND | 0 |
| Town of Iowa Water System LA1019026 | Calcasieu Parish County | ND | ND | 0 |
| Town of Jena Water System LA1059003 | La Salle Parish County | ND | ND | 0 |
| Town of Lake Arthur Water System LA1053005 | Jefferson Davis Parish County | ND | ND | 0 |
| Town of Leonville Water System LA1097005 | St. Landry Parish County | ND | ND | 0 |
| Town of Livingston Water System LA1063013 | Livingston Parish County | ND | ND | 0 |
| Town of Mamou Water System LA1039005 | Evangeline Parish County | ND | ND | 0 |
| Town of Maringouin LA1047003 | Iberville Parish County | ND | ND | 0 |
| Town of Pearl River LA1103157 | St. Tammany Parish County | ND | ND | 0 |
| Town of Plaucheville Water Systm LA1009013 | Avoyelles Parish County | ND | ND | 0 |
| Town of Port Barre Water System LA1097013 | St. Landry Parish County | ND | ND | 0 |
| Town of Sunset Water System LA1097015 | St. Landry Parish County | ND | ND | 0 |
| Town of Vinton Water System LA1019048 | Calcasieu Parish County | ND | ND | 0 |
| Town of Welsh Water System LA1053006 | Jefferson Davis Parish County | ND | ND | 0 |
| Town of Woodworth Water System LA1079027 | Rapides Parish County | ND | ND | 0 |
| United Water System LA1099009 | St. Martin Parish County | ND | ND | 0 |
| Utilities Inc - Kingspoint Subdivision LA1103055 | St. Tammany Parish County | ND | ND | 0 |
| Utilities Inc - North Park Water Supply LA1103124 | St. Tammany Parish County | ND | ND | 0 |
| Varnado Water Works LA1117006 | Washington Parish County | ND | ND | 0 |
| Varnado Water Works - Pine LA1117025 | Washington Parish County | ND | ND | 0 |
| Vermilion Waterworks District 1 LA1113034 | Vermilion Parish County | ND | ND | 0 |
| Vernon Parish Water and Sewer Commission LA1115071 | Vernon Parish County | ND | ND | 0 |
| Village Water System LA1015018 | Bossier Parish County | ND | ND | 1 |
| Village of Parks Water System LA1099008 | St. Martin Parish County | 6.4 | 4.3 | 4 |
| Village of Turkey Creek Water System LA1039013 | Evangeline Parish County | ND | ND | 0 |
| Vivian Water System LA1017037 | Caddo Parish County | ND | ND | 0 |
| W Jefferson WW District 2 LA1051004 | Jefferson Parish County | ND | ND | 1 |
| WBR District 4 -Section Road Winterville LA1121027 | West Baton Rouge Parish County | ND | ND | 0 |
| WBR Public Utilities LA1121008 | West Baton Rouge Parish County | ND | ND | 0 |
| WWKS District 2 of St Helena LA1091007 | St. Helena Parish County | ND | ND | 0 |
| Walker Water System LA1063017 | Livingston Parish County | ND | ND | 0 |
| Ward II Water District LA1063039 | Livingston Parish County | ND | ND | 0 |
| Water & Sewer Commission 4 of St Mary LA1101011 | St. Mary Parish County | ND | ND | 1 |
| Waterworks District 7 LA1017052 | Caddo Parish County | ND | ND | 0 |
| Wesley Chapel Water System LA1061020 | Lincoln Parish County | ND | ND | 0 |
| West Baton Rouge Water Works District 2 LA1121018 | West Baton Rouge Parish County | ND | ND | 0 |
| West Feliciana Consol WWKS District 13 LA1125010 | West Feliciana Parish County | ND | ND | 0 |
| West Grant Water Association LA1043014 | Grant Parish County | ND | ND | 0 |
| West Hwy 80 Ark Road WS LA1073055 | Ouachita Parish County | ND | ND | 0 |
| West Monroe Water System LA1073056 | Ouachita Parish County | ND | ND | 0 |
| West Vernon Parish Waterworks District LA1115121 | Vernon Parish County | ND | ND | 0 |
| Westlake City of Water System LA1019054 | Calcasieu Parish County | ND | ND | 0 |
| Westview Water Works LA1105028 | Tangipahoa Parish County | ND | ND | 0 |
| Westwego Waterworks LA1051005 | Jefferson Parish County | ND | ND | 0 |
| Winnsboro Water System LA1041006 | Franklin Parish County | ND | ND | 0 |
| Zachary Water System LA1033030 | East Baton Rouge Parish County | ND | ND | 0 |
ND = not detected (below the 4 ppt UCMR 5 reporting level). Values are the highest single sample result, not an annual average.