Louisiana Water Report Card: Worst Water Systems
The most contaminated public water systems in Louisiana, ranked by PFAS levels, lead, and EPA violations from official EPA data.
Quick Answer
Water & Sewer Commission 4 Of St Mary has the highest PFAS in Louisiana at 22.9 ppt (6x the EPA limit). Lakeview Water System has the highest lead at 32 ppb. The tables below rank the worst systems in each category so you can see how your water compares.
Highest PFAS Levels in Louisiana
Public water systems in Louisiana with the highest peak PFAS ("forever chemical") reading in EPA UCMR5 testing (2023-2025). The EPA enforceable limit for PFOA and PFOS is 4 ppt.
| # | Water System | Location | Peak PFAS (ppt) | Compounds | vs 4 ppt limit |
|---|---|---|---|---|---|
| 1 | Water & Sewer Commission 4 Of St Mary | Charenton · 9,709 served | 22.9 | 1 | 6x |
| 2 | Assumption Parish Ww District 1 | Napoleonville · 21,366 served | 15 | 2 | 4x |
| 3 | Pointe Coupee Water Works District 1 | New Roads · 10,629 served | 14.5 | 1 | 4x |
| 4 | City Of Plaquemine Water System | Plaquemine · 14,043 served | 14.2 | 3 | 4x |
| 5 | St Charles Parish Dept Of Waterworks | Luling · 52,879 served | 13.6 | 1 | 3x |
| 6 | New Orleans Carrollton Ww | New Orleans · 334,903 served | 9.1 | 5 | 2x |
| 7 | New Orleans Algiers Water Works | New Orleans · 52,785 served | 8.5 | 2 | 2x |
| 8 | South Toledo Bend Water District | Many · 5,943 served | 8.2 | 1 | 2x |
| 9 | Monroe Water System, La | Monroe · 57,000 served | 8.2 | 1 | 2x |
| 10 | St Tam Parish - Cross Gates Sd | Covington · 8,037 served | 8.2 | 1 | 2x |
| 11 | Belle Chasse Water District | Belle Chasse · 19,644 served | 8.1 | 1 | 2x |
| 12 | Houma Water Treatment Service Area | Houma · 11,658 served | 8 | 1 | 2x |
Highest Lead Levels in Louisiana
Community water systems in Louisiana with the highest 90th-percentile lead result under the EPA Lead and Copper Rule. The EPA action level is 15 ppb; there is no safe level of lead for children.
| # | Water System | Location | Lead 90th-pctile (ppb) | vs 15 ppb |
|---|---|---|---|---|
| 1 | Lakeview Water System | Shreveport · 2,025 served | 32 | 2.1x over |
| 2 | Mansfield Water System | Mansfield · 7,512 served | 23 | 1.5x over |
| 3 | St Joseph Water System | St Joseph · 1,332 served | 18 | 1.2x over |
| 4 | Sandy Lake Water Supply | Jonesville · 3,141 served | 18 | 1.2x over |
| 5 | Archibald Water System | Archibald · 4,200 served | 16 | 1.1x over |
| 6 | City Of Alexandria Water System | Alexandria · 66,798 served | 16 | 1.1x over |
| 7 | Brownville Water System | West Monroe · 9,696 served | 14 | within |
| 8 | Campti Water System | Campti · 1,515 served | 13 | within |
| 9 | Sligo Water System Incorporated | Coushatta · 2,850 served | 12 | within |
| 10 | Belah Fellowship Water System | Jena · 1,806 served | 12 | within |
| 11 | Tallulah Water System | Tallulah · 8,601 served | 12 | within |
| 12 | Village Of Harrisonburg Water System | Harrisonburg · 1,530 served | 12 | within |
Most EPA Violations in Louisiana
Community water systems in Louisiana with the most health-based EPA Safe Drinking Water Act violations on record. A health-based violation means a contaminant exceeded its federal limit or required treatment was not applied.
| # | Water System | Location | Health-based violations |
|---|---|---|---|
| 1 | Pendleton Water Association | Many · 2,634 served | 114 |
| 2 | Lake St John Waterworks District 1 | Ferriday · 2,067 served | 89 |
| 3 | Fairview Union Water System | Coushatta · 2,346 served | 81 |
| 4 | Town Of Ferriday Water System | Ferriday · 3,816 served | 77 |
| 5 | Oil City Water Works | Oil City · 2,148 served | 74 |
| 6 | Alberta Water System | Castor · 1,860 served | 72 |
| 7 | Bellwood Water System | Provencal · 1,032 served | 65 |
| 8 | West Winn Water System Inc | Winnfield · 2,064 served | 64 |
| 9 | Ebarb Wwks Dist #1 - North Ebarb | Zwolle · 1,761 served | 61 |
| 10 | Red Hill Waterworks Inc. | Harrisonburg · 1,914 served | 56 |
| 11 | Newellton Water System | Newellton · 1,100 served | 51 |
| 12 | Franklin Water Supply | Franklin · 8,325 served | 47 |
How This Report Card Is Built
PFAS rankings use EPA UCMR5 monitoring (2023-2025), showing each system's peak detection above the 4 ppt EPA limit. Lead rankings use the EPA Lead and Copper Rule 90th-percentile tap results. Violation counts come from the EPA Safe Drinking Water Information System (SDWIS) and count health-based violations. Lead and violation lists are limited to community water systems serving 1,000 or more people. Figures are the most severe on record and do not necessarily reflect current treated water.
Frequently Asked Questions
What is the most PFAS-contaminated water system in Louisiana?
In EPA UCMR5 testing (2023-2025), Water & Sewer Commission 4 Of St Mary in Charenton had the highest recorded PFAS level in Louisiana at 22.9 ppt - about 6x the EPA's 4 ppt limit for PFOA and PFOS.
Which Louisiana water system has the highest lead levels?
Lakeview Water System in Shreveport had the highest 90th-percentile lead result in Louisiana under the EPA Lead and Copper Rule at 32 ppb - 2.1x the 15 ppb action level.
Which Louisiana water system has the most EPA violations?
Pendleton Water Association in Many has the most health-based EPA Safe Drinking Water Act violations on record in Louisiana, with 114 violations.
Where does the Louisiana water report card data come from?
PFAS figures come from EPA UCMR5 monitoring (2023-2025), lead from the EPA Lead and Copper Rule 90th-percentile tap results, and violations from EPA SDWIS health-based violation records. Figures are the most severe on record and do not necessarily reflect current treated water. Check your exact address at knowyourexposure.com.
What Louisiana Residents Should Do
- Look up your exact address at knowyourexposure.com for your system's data
- See the full Louisiana water quality overview
- If your system is listed, a certified filter (reverse osmosis for PFAS, NSF-53 for lead) reduces exposure at the tap. See the best water filters.