17 named for arsenic itself on the list.
Per the state list or a state web page. Call to confirm.
Located outside Missouri but on its list.
USGS estimate for Missouri.
How many labs test for arsenic in Missouri
17 labs on Missouri's official drinking-water lab list are certified to test for arsenic. All 17 are named for arsenic on the list. The Missouri list does not say which labs take samples from homeowners, so call a lab before you send one. 11 are located outside Missouri.
The list is published by the Missouri Department of Natural Resources (chemical labs) + Department of Health and Senior Services (microbiological labs). List version on file: Live export fetched 2026-11-15 (no list date printed in the file). Fetched 2026-11-15 (UTC).
Missouri labs certified for arsenic
| Lab | Location | Arsenic certification | Public samples | Cert. expiry |
|---|---|---|---|---|
| Brighton Analytical LLC | Brighton, MI | Named on the official list | Public samples: ask the lab | 12/31/2027 |
| Brothers Lab Services | Maryland Heights, MO | Named on the official list | Public samples: ask the lab | 4/30/2028 |
| EMSL Analytical Inc.-Indianapolis | Indianapolis, IN | Named on the official list | Public samples: ask the lab | 3/31/2029 |
| EMSL Analytical Inc.-St. Louis | St. Louis, MO | Named on the official list | Public samples: ask the lab | 5/31/2027 (chemical); 8/31/2029 (microbiological) |
| Eurofins Lancaster Laboratories Environment Testing LLC | Lancaster, PA | Named on the official list | Public samples: ask the lab | 1/31/2028 |
| Eurofins South Bend | South Bend, IN | Named on the official list | Public samples: ask the lab | 9/30/2027 |
| Kansas City Water Services Laboratory | Kansas City, MO | Named on the official list | Public samples: ask the lab | 4/30/2027 (chemical); 10/31/2027 (microbiological) |
| Microbac Laboratories Inc.-Newton | Newton, IA | Named on the official list | Public samples: ask the lab | 4/30/2029 |
| Missouri Department of Natural Resources-Environmental Services CAS Laboratory | Jefferson City, MO | Named on the official list | Public samples: ask the lab | 7/31/2026 Date on list has passed |
| National Testing Laboratories Ltd. | Ypsilanti, MI | Named on the official list | Public samples: ask the lab | 12/31/2027 |
| Pace Analytical National Center for Testing and Innovation | Mount Juliet, TN | Named on the official list | Public samples: ask the lab | 9/30/2028 |
| Pace Analytical Services LLC-Florida | Ormond Beach, FL | Named on the official list | Public samples: ask the lab | 6/30/2028 |
| Pace Analytical Services LLC-Illinois | Peoria, IL | Named on the official list | Public samples: ask the lab | 6/30/2028 |
| Teklab Inc. | Collinsville, IL | Named on the official list | Public samples: ask the lab | 10/31/2026 (microbiological); 1/31/2028 (chemical) Date on list has passed |
| American Water Central Laboratory | Belleville, IL | Named on the official list | Public samples: ask the lab Looks like a utility or municipal lab, judging by the name (our label, not the state list) | 10/31/2027 |
| City of St. Louis-Chain of Rocks Laboratory | St. Louis, MO | Named on the official list | Public samples: ask the lab Looks like a utility or municipal lab, judging by the name (our label, not the state list) | 9/30/2029 |
| City Utilities of Springfield | Springfield, MO | Named on the official list | Public samples: ask the lab Looks like a utility or municipal lab, judging by the name (our label, not the state list) | 12/31/2027 (chemical); 5/31/2028 (microbiological) |
How the Missouri list marks public samples (whole list). Not stated in the list.
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 Missouri
Arsenic is invisible, tasteless and mostly natural, and it comes in two forms that respond very differently to treatment. Read our arsenic explainer.
USGS estimates that the most private-well users with arsenic above 10 µg/L, EPA's limit for public water, live in Greene County, Lincoln County and Pettis County (about 618 people in Greene County, 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. [1]
Show the numbers
| Item | Value | Note |
|---|---|---|
| Greene County | 618 people (2010 base year) | |
| Lincoln County | 548 people (2010 base year) | |
| Pettis County | 488 people (2010 base year) | |
| Franklin County | 467 people (2010 base year) | |
| Camden County | 434 people (2010 base year) | |
| Cape Girardeau County | 394 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 821,343 people in Missouri used private wells in 2015, by the USGS estimate of people on domestic self-supplied water. [2] 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: Missouri.
Other tests in Missouri
- 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)
- Missouri DNR - Certified Chemical Laboratories (spreadsheet of all laboratories) (official list)
- Missouri DNR - Certified Chemical Laboratories (spreadsheet of all laboratories) + Missouri DNR - Certified Microbiological Laboratories (spreadsheet of all laboratories) (official list)
Missouri DNR - Certified Chemical Laboratories (spreadsheet of all laboratories).
Official source