268 public water systems in Louisiana were sampled in EPA's UCMR 5 programme (2023–2025); we show six PFAS and lithium. Read 2026-10-31.
7 of 268 systems had at least one sample above a 2024 federal limit; 202 had at least one PFAS found above the reporting level; 66 had none found above the reporting level.
A single sample above a 2024 limit is a measurement, not a violation. Compliance is judged on running yearly averages, and water systems have until 2029 to meet the limits. On 20 May 2026 EPA proposed giving qualifying systems until 2031 for PFOA and PFOS and removing the limits for PFHxS, PFNA and HFPO-DA; those proposals were not final when we last checked (5 Nov 2026). Counts are per system, not per person; population figures are available only for systems serving more than 25,000 people (about 2,705,925 people across those systems here). UCMR 5 was a one-time national monitoring programme (2023–2025). The results are a snapshot at the system's entry points or taps on the sample dates, not a continuous measurement and not a compliance record.
| System | People served | UCMR 5 result |
|---|---|---|
| Baton Rouge Baton Rouge Water Company | 596,844 | None detected (below the reporting level) |
Pages for these are being added in stages. The data for all 268 systems is in the public dataset.
| System | People served | UCMR 5 result |
|---|---|---|
| New Orleans Carrollton Ww New Orleans Carrollton Ww | 334,903 | Above the 2024 limit in at least one sample |
| E Jefferson Ww District 1 E Jefferson Ww District 1 | 275,163 | None detected (below the reporting level) |
| Shreveport Water System Shreveport Water System | 192,378 | None detected (below the reporting level) |
| Lafayette Utilities Water System Lafayette Utilities Water System | 169,389 | None detected (below the reporting level) |
| W Jefferson Ww District 2 W Jefferson Ww District 2 | 140,264 | None detected (below the reporting level) |
| Schriever Water Treatment Service Area Schriever Water Treatment Service Area | 116,460 | None detected (below the reporting level) |
| Lafourche Water District 1 Lafourche Water District 1 | 81,609 | None detected (below the reporting level) |
| City of Bossier City Water System City of Bossier City Water System | 79,506 | None detected (below the reporting level) |
| City of Lake Charles Water System City of Lake Charles Water System | 79,500 | None detected (below the reporting level) |
| Ward Ii Water District Ward Ii Water District | 78,147 | None detected (below the reporting level) |
| Tangipahoa Parish Water District Tangipahoa Parish Water District | 75,873 | None detected (below the reporting level) |
| City of Alexandria Water System City of Alexandria Water System | 66,798 | None detected (below the reporting level) |
| New Iberia Water System (Lawco) New Iberia Water System (Lawco) | 59,928 | None detected (below the reporting level) |
| Monroe Water System, La Monroe Water System, La | 57,000 | None detected (below the reporting level) |
| St Charles Parish Dept of Waterworks St Charles Parish Dept of Waterworks | 52,879 | None detected (below the reporting level) |
| New Orleans Algiers Water Works New Orleans Algiers Water Works | 52,785 | Above the 2024 limit in at least one sample |
| St Bernard Parish Waterworks St Bernard Parish Waterworks | 44,783 | None detected (below the reporting level) |
| Slidell Water Supply Slidell Water Supply | 35,547 | None detected (below the reporting level) |
| St John Water District 3 St John Water District 3 | 31,965 | None detected (below the reporting level) |
| Zachary Water System Zachary Water System | 31,569 | None detected (below the reporting level) |
| Natchitoches Water System Natchitoches Water System | 26,910 | None detected (below the reporting level) |
| City of Denham Springs Water System City of Denham Springs Water System | 25,725 | None detected (below the reporting level) |
| Town of Church Point Water System Town of Church Point Water System | — | None detected (below the reporting level) |
| Crowley Water System (Lawco) Crowley Water System (Lawco) | — | None detected (below the reporting level) |
| City of Rayne Water System City of Rayne Water System | — | None detected (below the reporting level) |