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Louisiana Water Quality
643
Utilities in database
5.2M
Residents served
18%
On private wells
2
Key contaminants tracked
Drinking Water in Louisiana
Louisiana has 643 community water systems serving approximately 5.2 million residents. Primary water sources include groundwater. The most commonly reported contaminants include disinfection byproducts, nitrates. 18% of Louisiana residents rely on private wells. DEQ holds primary enforcement authority under the Safe Drinking Water Act.
Utilities in Louisiana
Top 20 of 643 by populationBaton Rouge Water Company
LA1033005 · 596,844 served
New Orleans Carrollton Water Works
LA1071009 · 334,903 served
E Jefferson Ww District 1
LA1051001 · 275,163 served
Shreveport Water System
LA1017031 · 192,378 served
Lafayette Utilities Water System
LA1055017 · 169,389 served
W Jefferson Ww District 2
LA1051004 · 140,264 served
Schriever Water Treatment Service Area
LA1109002 · 116,460 served
Lafourche Water District 1
LA1057001 · 81,609 served
City of Lake Charles Water System
LA1019029 · 79,500 served
City of Bossier City Water System
LA1015004 · 78,960 served
Ward Ii Water District
LA1063039 · 73,506 served
Tangipahoa Parish Water District
LA1105008 · 72,504 served
City of Alexandria Water System
LA1079001 · 66,798 served
New Iberia Water System (lawco)
LA1045009 · 59,928 served
Monroe Water System
LA1073031 · 57,000 served
St Charles Parish Dept of Waterworks
LA1089001 · 52,879 served
New Orleans Algiers Water Works
LA1071001 · 52,785 served
St Bernard Parish Waterworks
LA1087001 · 44,783 served
Slidell Water Supply
LA1103041 · 35,547 served
St John Water District 3
LA1095007 · 31,965 served
Key Contaminant Concerns in Louisiana
Nitrates
Nitrate (NO₃⁻) is a nitrogen-containing compound that forms naturally through the decomposition of organic matter. At elevated concentrations — almost always from human activity — nitrate interferes with the blood's ability to carry oxygen. The United States produces over 23 million tons of nitrogen fertilizer annually, making agricultural runoff the dominant source of nitrate contamination.
DBPs
When utilities add chlorine to water to kill pathogens, it reacts with dissolved organic matter — leaves, algae, soil — to produce disinfection byproducts (DBPs). Over 600 DBPs have been identified. The EPA regulates two groups: total trihalomethanes (TTHMs, including chloroform) and haloacetic acids (HAA5). DBP levels tend to be highest in surface water systems and in warm months when organic matter is elevated.
Louisiana Water FAQs
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Data source: Utility data from EPA SDWIS. 643 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-19