countyscore

Water Quality · Louisiana

Best Water Quality Counties in Louisiana 2026

Ranked by EPA drinking water health violations.

Top 10 — Water Quality in Louisiana

Score reflects water quality only — not overall county quality.

1Assumption Parish, LA
86
2Lafourche Parish, LA
86
3St. Bernard Parish, LA
86
4St. Charles Parish, LA
86
5St. John the Baptist Parish, LA
86
6Terrebonne Parish, LA
86
7East Baton Rouge Parish, LA
70.4
8Jefferson Parish, LA
69
9Orleans Parish, LA
65.8
10West Baton Rouge Parish, LA
65.3

All Louisiana Counties — Water Quality Rankings

63 counties ranked by water quality score. Overall Score shown for context.

#CountyWater Quality ScoreOverall Score
1Assumption Parish, LA
86
69.4
2Lafourche Parish, LA
86
47.1
3St. Bernard Parish, LA
86
42.5
4St. Charles Parish, LA
86
48.8
5St. John the Baptist Parish, LA
86
43.1
6Terrebonne Parish, LA
86
43.5
7East Baton Rouge Parish, LA
70.4
31.4
8Jefferson Parish, LA
69
34.2
9Orleans Parish, LA
65.8
24
10West Baton Rouge Parish, LA
65.3
46.9
11West Feliciana Parish, LA
62.8
65.8
12Jefferson Davis Parish, LA
58.3
53.1
13East Feliciana Parish, LA
51.3
61.8
14Rapides Parish, LA
46.5
36
15Beauregard Parish, LA
44.8
57.1
16Calcasieu Parish, LA
43.6
44.6
17Lafayette Parish, LA
41.1
34.3
18Livingston Parish, LA
40.6
43.3
19Pointe Coupee Parish, LA
40
54.3
20St. Tammany Parish, LA
36.4
44.1
21Vernon Parish, LA
36.3
64.3
22Tangipahoa Parish, LA
35.4
34.1
23Iberia Parish, LA
33.5
59.3
24Vermilion Parish, LA
27.1
57.6
25Avoyelles Parish, LA
27
58.3
26Catahoula Parish, LA
25.7
58.9
27Washington Parish, LA
25.5
46.4
28Caddo Parish, LA
23.8
47.7
29St. Helena Parish, LA
23.8
46.9
30St. Landry Parish, LA
23.7
46.1
31St. James Parish, LA
23.4
51.8
32Webster Parish, LA
23.1
58.1
33Ascension Parish, LA
21.8
41.2
34Bossier Parish, LA
21.6
36.2
35Ouachita Parish, LA
20.8
35.3
36St. Martin Parish, LA
19.8
47.6
37Allen Parish, LA
18.9
68.4
38Franklin Parish, LA
18.8
54
39Claiborne Parish, LA
18.7
68.8
40Evangeline Parish, LA
16.9
50.6
41West Carroll Parish, LA
16.8
68.4
42Acadia Parish, LA
16
55.4
43St. Mary Parish, LA
14.4
48.9
44Iberville Parish, LA
14.1
52.2
45Madison Parish, LA
14
56.6
46Lincoln Parish, LA
12.5
49.8
47Plaquemines Parish, LA
10.5
54.9
48Richland Parish, LA
9.8
58.1
49Morehouse Parish, LA
6.6
42.2
50Natchitoches Parish, LA
5.6
63.1
51De Soto Parish, LA
5.2
65.1
52Grant Parish, LA
5
53.8
53East Carroll Parish, LA
4.9
63.3
54Red River Parish, LA
3.1
64.2
55Jackson Parish, LA
3
64.2
56Caldwell Parish, LA
2.9
58.8
57Concordia Parish, LA
2.8
45.8
58Bienville Parish, LA
2.3
64.2
59Cameron Parish, LA
2.3
75.1
60Sabine Parish, LA
1.8
63.8
61Tensas Parish, LA
1.7
59.6
62Union Parish, LA
1.2
66.8
63Winn Parish, LA
0.9
67.8

Explore More

Best overall counties in LouisianaFull Water Quality data on WaterByCounty