Water in Louisiana.
Louisiana's Mississippi River source water passes downstream of every major U.S. industrial corridor. Cancer Alley between Baton Rouge and New Orleans has the highest cancer-risk pollution exposure in the country, with water playing a role in cumulative exposure.
Louisiana's Cancer Alley is among the most-studied environmental-health zones in U.S. history.
How Louisiana regulates drinking water.
Federal SDWA primacy. No state MCLs stricter than federal. Cancer Alley enforcement has been a long-running EPA Region 6 priority.
Louisiana Department of Health — Office of Public Health, Engineering Services
Louisiana's water history, in order.
The contamination events, regulatory shifts, and major settlements that define how this state thinks about drinking water today.
- 2016
St. James Parish Cancer Alley water-quality reporting becomes national news.
- 2020
EPA Civil Rights Title VI investigation opened on cumulative-exposure complaints in Cancer Alley.
- 2024
PFAS contamination identified at multiple Louisiana refineries.
The actual water you drink.
The physical rivers, aquifers, lakes, and reservoirs that feed Louisiana's public water systems. Source quality is the foundation of tap quality — and where the long-term protection fights happen.
- riverMississippi River
New Orleans, Baton Rouge — downstream of every major U.S. industrial corridor.
- aquiferSparta Aquifer
Northern LA.
- aquiferChicot Aquifer
Southwest LA.
- riverCalcasieu River
Lake Charles area.
Source-water mix
~55% surface water (Mississippi), ~45% groundwater
Major cities served
New Orleans · Baton Rouge · Shreveport · Lafayette · Lake Charles
Who actually serves the water.
The largest public water systems in Louisiana by population served. Click your ZIP after to see the full live EWG report for your specific utility.
- Sewerage and Water Board of New OrleansNew Orleans380Kserved
- Baton Rouge Water CompanyBaton Rouge250Kserved
- Shreveport Water DepartmentShreveport190Kserved
Where the contamination comes from.
Every state has a different industrial fingerprint. The industries below are the dominant historical and active contamination sources in Louisiana's drinking water systems.
Cancer Alley between Baton Rouge and New Orleans hosts 150+ petrochemical and refinery facilities — the highest cumulative-exposure corridor in the U.S. Offshore oil-and-gas brine discharge affects coastal groundwater. Chlor-alkali operations in Lake Charles drive mercury concerns.
What state data flags most consistently.
Drawn from EPA SDWIS sampling records, EWG state summaries, and regional regulatory action over the past five years. Read the full deep dive on each.
Trihalomethanes (TTHMs)
Byproducts of chlorinating water. Linked to bladder cancer at chronic exposure.
PFAS (Forever Chemicals)
A class of ~15,000 synthetic chemicals that don't break down. Now regulated for the first time.
Chromium-6 (Hexavalent Chromium)
The Erin Brockovich chemical. A known carcinogen with no federal-specific limit yet.
Lead
A neurotoxic metal that leaches from old pipes and solder. No safe level for children.
Risk isn't evenly distributed.
Cancer Alley residents — disproportionately Black — face combined air, water, and soil chemical exposure that has no parallel in U.S. environmental health.
~10% on private wells, mostly rural northern Louisiana.
What's coming for Louisiana's water.
Sea-level rise + sinking land = some of the most-vulnerable coastal water infrastructure in the U.S. Hurricane intensity (Ida, Laura) regularly disables treatment plants. Saltwater intrusion up the Mississippi River reached New Orleans in 2023.
Voluntary statewide
Louisiana Department of Health provides voluntary technical assistance.
Five questions for your next Consumer Confidence Report.
Your utility is required to send you a Consumer Confidence Report annually. Most are dense and procedural. These are the questions worth following up on for Louisiana specifically.
- 1
If I'm in Cancer Alley, what's my utility's full chemical-by-chemical contaminant report?
- 2
Has my system experienced saltwater intrusion advisories?
- 3
How does my utility respond to refinery upsets near my intake?
Most state regulators allow public records requests for the underlying lab reports behind your CCR — your utility should be able to provide them on request.
What's changed in Louisiana water law.
Drinking water regulation moves at the state level as much as the federal level. Below are notable recent bills and regulatory actions specific to Louisiana.
- 2023
Cancer Alley federal civil rights investigation (EPA Title VI) reaches major settlement milestone.
Reverse osmosis (NSF/ANSI 58) for the broadest protection against the multi-contaminant industrial profile in Cancer Alley.
We don't recommend brands — the NSF/ANSI certification number matters more than the name on the box.
This is the state. Your address is the answer.
State-level patterns don't tell you about your specific tap. Run your ZIP for the live EWG contaminant report on your utility — or build a personalized Water File for your household.
Source-water mix, utility counts, lead-service-line estimates, and private-well shares are approximate, drawn from EPA SDWIS public data and state primacy-agency summaries. Contaminant rankings reflect EWG state-level monitoring data and regional regulatory action — they are not exhaustive. Timeline events are publicly documented. See methodology for the full sourcing. Search EPA SDWIS for Louisiana