Louisiana water quality by county
64 counties with public water systems. Pick a county to see every system that serves it.
| County | Active systems | People served | Share with violations, 3 yr | Serious violators | Health flags |
|---|---|---|---|---|---|
| Acadia Parish | 13 | 63,247 | 0 | 4 | |
| Allen Parish | 10 | 32,229 | 0 | 0 | |
| Ascension Parish | 29 | 35,581 | 2 | 4 | |
| Assumption Parish | 1 | 21,366 | 0 | 0 | |
| Avoyelles Parish | 17 | 52,881 | 1 | 1 | |
| Beauregard Parish | 8 | 50,010 | 0 | 0 | |
| Bienville Parish | 22 | 17,163 | 5 | 9 | |
| Bossier Parish | 25 | 149,314 | 8 | 14 | |
| Caddo Parish | 49 | 249,833 | 6 | 10 | |
| Calcasieu Parish | 80 | 215,171 | 3 | 12 | |
| Caldwell Parish | 11 | 16,233 | 3 | 4 | |
| Cameron Parish | 8 | 12,647 | 0 | 0 | |
| Catahoula Parish | 7 | 12,708 | 2 | 1 | |
| Claiborne Parish | 12 | 20,938 | 1 | 3 | |
| Concordia Parish | 8 | 25,845 | 2 | 2 | |
| De Soto Parish | 12 | 34,752 | 2 | 4 | |
| East Baton Rouge Parish | 19 | 650,087 | 0 | 1 | |
| East Carroll Parish | 4 | 8,070 | 1 | 2 | |
| East Feliciana Parish | 10 | 27,684 | 1 | 1 | |
| Evangeline Parish | 14 | 43,633 | 1 | 5 | |
| Franklin Parish | 7 | 25,752 | 3 | 4 | |
| Grant Parish | 13 | 25,910 | 5 | 7 | |
| Iberia Parish | 15 | 75,947 | 2 | 3 | |
| Iberville Parish | 13 | 44,927 | 1 | 2 | |
| Jackson Parish | 19 | 18,119 | 4 | 8 | |
| Jefferson Davis Parish | 8 | 38,275 | 0 | 1 | |
| Jefferson Parish | 4 | 440,987 | 0 | 0 | |
| LaSalle Parish | 12 | 19,338 | 0 | 1 | |
| Lafayette Parish | 61 | 303,509 | 6 | 9 | |
| Lafourche Parish | 2 | 96,471 | 0 | 0 | |
| Lincoln Parish | 22 | 60,724 | 2 | 4 | |
| Livingston Parish | 32 | 160,710 | 1 | 4 | |
| Madison Parish | 4 | 13,542 | 1 | 2 | |
| Morehouse Parish | 15 | 31,947 | 3 | 6 | |
| Natchitoches Parish | 13 | 43,219 | 1 | 3 | |
| Orleans Parish | 10 | 389,093 | 0 | 0 | |
| Ouachita Parish | 31 | 188,938 | 0 | 3 | |
| Plaquemines Parish | 5 | 32,282 | 0 | 0 | |
| Pointe Coupee Parish | 11 | 31,094 | 0 | 2 | |
| Rapides Parish | 24 | 165,830 | 0 | 3 | |
| Red River Parish | 12 | 12,413 | 2 | 5 | |
| Richland Parish | 12 | 25,635 | 1 | 3 | |
| Sabine Parish | 19 | 40,380 | 5 | 7 | |
| St. Bernard Parish | 2 | 45,143 | 0 | 0 | |
| St. Charles Parish | 1 | 52,879 | 0 | 0 | |
| St. Helena Parish | 6 | 10,609 | 1 | 2 | |
| St. James Parish | 5 | 22,854 | 1 | 2 | |
| St. John the Baptist Parish | 12 | 47,793 | 0 | 2 | |
| St. Landry Parish | 29 | 112,371 | 4 | 5 | |
| St. Martin Parish | 24 | 79,335 | 6 | 9 | |
| St. Mary Parish | 16 | 63,113 | 3 | 1 | |
| St. Tammany Parish | 207 | 267,954 | 10 | 28 | |
| Tangipahoa Parish | 37 | 133,782 | 1 | 12 | |
| Tensas Parish | 5 | 8,336 | 2 | 2 | |
| Terrebonne Parish | 2 | 128,118 | 0 | 0 | |
| Union Parish | 20 | 32,769 | 3 | 9 | |
| Vermilion Parish | 12 | 70,591 | 0 | 3 | |
| Vernon Parish | 19 | 65,567 | 0 | 4 | |
| Washington Parish | 35 | 34,791 | 4 | 11 | |
| Webster Parish | 30 | 51,859 | 4 | 8 | |
| West Baton Rouge Parish | 7 | 30,886 | 1 | 0 | |
| West Carroll Parish | 7 | 14,565 | 1 | 3 | |
| West Feliciana Parish | 4 | 20,986 | 0 | 0 | |
| Winn Parish | 13 | 17,209 | 3 | 6 |
under 30% 30 to 59% 60% and over
About this data
Share with violations counts any violation in the past three years, including monitoring and reporting lapses. Counts cover active systems; systems serving more than one county are counted in each.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Louisiana records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.