States → Louisiana
State profile · EPA SDWIS + UCMR5
Louisiana Drinking Water Quality
1,234 public water systems serve 5,316,532 people across Louisiana, with every Safe Drinking Water Act violation and UCMR5 PFAS result on record.
- 1,234
- Water systems
- 115,060
- Total violations
- 92.5%
- Systems w/ a violation
- 82.3%
- PFAS detection rate
The verdict
Across Louisiana, 1,142 of 1,234 water systems (92.5%) carry at least one EPA violation, and 218 of 265 UCMR5-tested systems show PFAS.
- 115,060
- Total EPA violations on record
- 54%
- Health-based (MCL / treatment)
- 92.5%
- Systems with ≥1 violation
- 82.3%
- UCMR5 PFAS detection rate
Water Systems
1,234
Total Violations
115,060
Violation Rate
92.5%
PFAS Detection
82.3%
218 of 265 tested
Violation Composition
How Louisiana's 115,060 violations break down by type, per EPA SDWIS classification.
Health-based (62,164) Monitoring/Reporting (52,896)
| Metric | Value | Share |
|---|---|---|
| Public water systems | 1,234 | - |
| Population served | 5,316,532 | - |
| Total violations | 115,060 | 100% |
| Health-based violations | 62,164 | 54.0% |
| Systems with violations | 1,142 | 92.5% |
| PFAS detection rate | 218 of 265 | 82.3% |
Health-based violations indicate the contaminant exceeded an EPA Maximum Contaminant Level (MCL) or treatment-technique requirement. Monitoring/reporting violations indicate procedural issues (missed tests, late reports) - not necessarily a contamination event.
Largest Water Systems
Baton Rouge Water Company
Baton Rouge, LA · 596,844 served
New Orleans Carrollton Water Works
New Orleans, LA · 334,903 served
E Jefferson Ww District 1
Jefferson, LA · 275,163 served
Shreveport Water System
Shreveport, LA · 192,378 served
Lafayette Utilities Water System
Lafayette, LA · 169,389 served
W Jefferson Ww District 2
Jefferson, LA · 140,264 served
Schriever Water Treatment Service Area
Houma, LA · 116,460 served
Lafourche Water District 1
Lockport, LA · 81,609 served
City of Lake Charles Water System
Lake Charles, LA · 79,500 served
City of Bossier City Water System
Bossier City, LA · 78,960 served
Ward II Water District
Denham Springs, LA · 73,506 served
Tangipahoa Parish Water District
Hammond, LA · 72,504 served
City of Alexandria Water System
Alexandria, LA · 66,798 served
New Iberia Water System (Lawco)
Baton Rouge, LA · 59,928 served
Monroe Water System
Monroe, LA · 57,000 served
St Charles Parish Dept of Waterworks
Luling, LA · 52,879 served
New Orleans Algiers Water Works
New Orleans, LA · 52,785 served
St Bernard Parish Waterworks
Chalmette, LA · 44,783 served
Slidell Water Supply
Slidell, LA · 35,547 served
St John Water District 3
Laplace, LA · 31,965 served
Most Violations
#1 Town of Ferriday Water System Ferriday
2,042 #2 Fairview Union Water System Coushatta
1,589 #3 Hudson Gaars Mill Water System Dodson
1,416 #4 Village of Sikes Water System Sikes
1,279 #5 Village of Calvin Water System Calvin
1,195 #6 Litroe Water System Marion
1,110 #7 Vixen Water System Alexandria
1,090 #8 Oil City Water Works Oil City
1,085 #9 Pendleton Water Association Many
1,060 #10 Union Parish Waterworks District 1 Farmerville
939 #11 Pleasant Hills-Crossroads Water Systems Joyce
916 #12 Alberta Water System Castor
837 #13 Magnolia-Spring Creek Subdivision Des Peres
799 #14 Belmont Waterworks Inc Belmont
790 #15 Ozone Pine Subdivision Slidell
789 Counties in Louisiana
East Baton Rouge Parish
19 systems · 650,087 served
· 566 violations
Jefferson Parish
4 systems · 440,987 served
· 247 violations
Orleans Parish
10 systems · 389,093 served
· 157 violations
Lafayette Parish
62 systems · 303,179 served
· 2,569 violations
St. Tammany Parish
213 systems · 266,825 served
· 7,149 violations
Caddo Parish
48 systems · 249,641 served
· 5,038 violations
Calcasieu Parish
80 systems · 216,042 served
· 3,535 violations
Ouachita Parish
31 systems · 188,938 served
· 4,888 violations
Rapides Parish
24 systems · 165,953 served
· 1,472 violations
Livingston Parish
33 systems · 155,925 served
· 997 violations
Bossier Parish
27 systems · 140,488 served
· 4,038 violations
Tangipahoa Parish
35 systems · 131,935 served
· 1,445 violations
Terrebonne Parish
2 systems · 128,118 served
· 50 violations
St. Landry Parish
29 systems · 111,945 served
· 2,173 violations
Lafourche Parish
2 systems · 96,471 served
· 191 violations
St. Martin Parish
25 systems · 77,708 served
· 1,995 violations
Iberia Parish
15 systems · 75,947 served
· 690 violations
Vermilion Parish
12 systems · 70,792 served
· 645 violations
Vernon Parish
20 systems · 66,152 served
· 623 violations
St. Mary Parish
16 systems · 63,659 served
· 1,325 violations
Lincoln Parish
22 systems · 60,724 served
· 1,889 violations
Acadia Parish
13 systems · 59,922 served
· 724 violations
Webster Parish
35 systems · 53,565 served
· 2,493 violations
St. Charles Parish
1 systems · 52,879 served
· 9 violations
Avoyelles Parish
17 systems · 52,812 served
· 674 violations
Beauregard Parish
9 systems · 50,035 served
· 303 violations
St. John the Baptist Parish
12 systems · 47,793 served
· 1,210 violations
St. Bernard Parish
2 systems · 45,143 served
· 447 violations
Iberville Parish
13 systems · 44,903 served
· 388 violations
Natchitoches Parish
14 systems · 44,641 served
· 3,262 violations
Showing top 30 of 64 counties.
Drinking Water Guides
Frequently Asked Questions
How many water systems are in Louisiana? ▼
Louisiana has 1,234 public water systems serving approximately 5,316,532 people. These include community water systems, non-transient non-community systems, and transient non-community systems regulated under the Safe Drinking Water Act.
How many drinking water violations are in Louisiana? ▼
Louisiana has 115,060 total drinking water violations on record, with 62,164 classified as health-based violations. 92.5% of water systems in the state have at least one violation.
Has PFAS been found in Louisiana drinking water? ▼
Of 265 water systems tested for PFAS in Louisiana, 218 had PFAS detected, a 82.3% detection rate. PFAS are persistent "forever chemicals" that do not break down in the environment.
What is the violation rate for Louisiana water systems? ▼
Louisiana's violation rate is 92.5%. This measures the percentage of public water systems that have at least one recorded violation in the EPA SDWIS database, including both health-based and monitoring/reporting violations.
Where does this Louisiana water data come from? ▼
All drinking water data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS is the federal database that tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources & Methodology
Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). PFAS testing data from the UCMR5 monitoring program. SDWIS tracks all public water systems regulated under the Safe Drinking Water Act.
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial
Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.