16 named for arsenic itself on the list.
Per the state list or a state web page. Call to confirm.
Located outside Louisiana but on its list.
USGS estimate for Louisiana.
How many labs test for arsenic in Louisiana
16 labs on Louisiana's official drinking-water lab list are certified to test for arsenic. All 16 are named for arsenic on the list. 15 of them are marked as taking samples from the public. They are listed first. 14 are located outside Louisiana.
The list is published by the Louisiana Department of Health (LDH), Office of Public Health - Laboratory Certification Program (Safe Drinking Water). List versions on file: Current as of 2/12/2026; Current as of 2/12/2026; March 2026. Fetched 2026-11-15 (UTC).
Louisiana labs certified for arsenic
Marked as taking public samples (15)
| Lab | Location | Arsenic certification | Public samples | Cert. expiry |
|---|---|---|---|---|
| American Water Central Laboratory | Belleville, IL | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| Element Materials Technology Fort Wayne, LLC | Fort Wayne, IN | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| EMSL Analytical, Inc. - Cinnaminson | Cinnaminson, NJ | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| Eurofins Orlando | Altamonte Springs, FL | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| Eurofins Pomona | Pomona, CA | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| Eurofins South Bend | South Bend, IN | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| GEL Laboratories, LLC | Charleston, SC | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| National Testing Laboratories, Ltd. | Ypsilanti, MI | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| Pace Analytical National Center for Testing & Innovation | Mt. Juliet, TN | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| Pace Analytical Services, LLC - Madisonville | Madisonville, KY | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| Pace Analytical Services, LLC - Minneapolis MN | Minneapolis, MN | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| Pace Analytical Services, LLC - Ormond Beach FL | Ormond Beach, FL | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| SGS North America Inc. - Wheat Ridge | Wheat Ridge, CO | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| SGS North America, Inc. - Scott | Scott, LA | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
| SPL, Inc. Kilgore | Kilgore, TX | Named on the official list | Public samples: yes (per state) | 12/31/2026 |
Other labs on the list (1)
| Lab | Location | Arsenic certification | Public samples | Cert. expiry |
|---|---|---|---|---|
| Jefferson Parish Water Quality Laboratory | Jefferson, LA | Named on the official list | Not marked as taking public samples | 12/31/2026 (chemistry); December 2027 (microbiology) |
How the Louisiana list marks public samples (whole list). LDH's chemistry list prints 'Accepts Commercial Samples: Yes/No' for each lab. 'Yes' means the lab accepts commercial samples, which is broader than 'homeowner', so call before you send a sample. The microbiology list does not say.
Before you send a sample, call the lab to confirm it is currently certified for the exact test and method, that it accepts samples from homeowners, and how to collect and ship them. Status can change between list updates.
Why test for arsenic in Louisiana
Arsenic is invisible, tasteless and mostly natural, and it comes in two forms that respond very differently to treatment. Read our arsenic explainer.
Louisiana guidance that mentions arsenic:
- LDH's well-testing brochure also recommends yearly preliminary tests for chemical contaminants: nitrate/nitrite and metals such as arsenic, lead and cadmium. [1]
- Louisiana does not require well testing when a home is sold, but lenders often ask for it. LDH offers a 'Water & Sewer Approval Request for Loan Letter' order online: a sanitarian collects a total coliform/E. coli sample and LDH drafts a letter for the owner or lender. For lender-required chemistry tests (lead, nitrate, arsenic), LDH lists certified labs. [2]
USGS estimates that the most private-well users with arsenic above 10 µg/L, EPA's limit for public water, live in St. Tammany Parish, Ascension Parish and Tangipahoa Parish (about 1,127 people in St. Tammany Parish, 2010 base year). USGS describes this kind of estimate as useful "for broad screening of the population at risk", so it says nothing certain about any one well. [3]
Show the numbers
| Item | Value | Note |
|---|---|---|
| St. Tammany Parish | 1,127 people (2010 base year) | |
| Ascension Parish | 610 people (2010 base year) | |
| Tangipahoa Parish | 545 people (2010 base year) | |
| Vermilion Parish | 427 people (2010 base year) | |
| Livingston Parish | 410 people (2010 base year) | |
| Lafayette Parish | 357 people (2010 base year) |
USGS model estimate for broad screening, not a measurement of any well. Only a test tells you about your own well. Source: USGS, Estimated county level domestic well population with arsenic greater than 10 micrograms per liter (Ayotte, Medalie and Qi, 2017), accessed 2026-11-01.
About 491,582 people in Louisiana used private wells in 2015, by the USGS estimate of people on domestic self-supplied water. [4] Federal limits are written for public water systems, not private wells, so testing is up to the owner.
For tests that depend on your home (farms nearby, old plumbing, a new baby), use the which-tests checklist. When results arrive, check your numbers against EPA's limits. State guidance, county data and every lab: Louisiana.
Other tests in Louisiana
- Louisiana Department of Health, Private Water Well Testing in Louisiana: What You Need to Know to Protect Your Water (brochure)
- Louisiana Department of Health, Real estate well testing requirements
- USGS, Estimated county level domestic well population with arsenic greater than 10 micrograms per liter (Ayotte, Medalie and Qi, 2017)
- USGS, Estimated use of water in the United States, county-level data for 2015 (Dieter et al., ver. 2.0, 2018)
- LDH - 2026 List of Laboratories Certified by Louisiana for Drinking Water Analyses - Chemistry (official list)
- LDH - 2026 List of Laboratories Certified by Louisiana for Drinking Water Analyses - Chemistry + LDH - List of Laboratories Certified by Louisiana for Drinking Water Analysis - Microbiology (official list)
LDH - 2026 List of Laboratories Certified by Louisiana for Drinking Water Analyses - Chemistry.
Official source