24 named for arsenic itself on the list.
Per the state list or a state web page. Call to confirm.
Located outside Illinois but on its list.
USGS estimate for Illinois.
How many labs test for arsenic in Illinois
24 labs on Illinois's official drinking-water lab list are certified to test for arsenic. All 24 are named for arsenic on the list. The Illinois list does not say which labs take samples from homeowners, so call a lab before you send one. 16 are located outside Illinois.
The list is published by the Illinois EPA - Environmental Laboratory Accreditation Program (IL ELAP, chemistry) and Illinois Department of Public Health (IDPH, water microbiology). List versions on file: 12/09/2025 (date in the file name; the PDF prints no date); Revision Date Thursday, December 4, 2025; TNI LAMS as fetched 2026-11-15; 12/09/2025 (date in the file name; the PDF prints no date); TNI LAMS as fetched 2026-11-15. Fetched 2026-11-15 (UTC).
Illinois labs certified for arsenic
| Lab | Location | Arsenic certification | Public samples | Cert. expiry |
|---|---|---|---|---|
| ALS-Global - Middletown | Middletown, PA | Named on the official list | Public samples: ask the lab | 11/30/2026 |
| Continental Water Laboratory | Sacramento, CA | Named on the official list | Public samples: ask the lab | 2/28/2027 |
| Culligan Analytical Laboratory | Rosemont, IL | Named on the official list | Public samples: ask the lab | 2/28/2027 (IL ELAP chemistry); Nov 2026 (IDPH microbiology) |
| Eurofins Chicago | Tinley Park, IL | Named on the official list | Public samples: ask the lab | 5/31/2027 |
| Eurofins Eaton Analytical, LLC - Pomona | Pomona, CA | Named on the official list | Public samples: ask the lab | 3/31/2027 |
| Eurofins Eaton Analytical, LLC -South Bend, IN | South Bend, IN | Named on the official list | Public samples: ask the lab | 9/30/2027 (IL ELAP chemistry); Jun 2026 (IDPH microbiology) Date on list has passed |
| Eurofins Lancaster Laboratories Environment Testing, LLC | Lancaster, PA | Named on the official list | Public samples: ask the lab | 1/31/2027 |
| First Environmental Laboratories, Inc. | Naperville, IL | Named on the official list | Public samples: ask the lab | 2/28/2027 |
| GEL Laboratories, LLC | Charleston, SC | Named on the official list | Public samples: ask the lab | 1/31/2028 |
| Lake County Environmental Laboratory | Libertyville, IL | Named on the official list | Public samples: ask the lab | 1/31/2027 (IL ELAP chemistry); Feb 2026 (IDPH microbiology) Date on list has passed |
| Metiri Analytical Group, Inc. fka. CWM Environmental | Kittanning, PA | Named on the official list | Public samples: ask the lab | 2/28/2027 |
| Microbac Laboratories, Inc. | Merrillville, IN | Named on the official list | Public samples: ask the lab | 6/30/2027 (IL ELAP chemistry); Mar 2026 (IDPH microbiology) Date on list has passed |
| Microbac Laboratories, Inc. - Marietta Division | Marietta, OH | Named on the official list | Public samples: ask the lab | 5/31/2027 |
| National Testing Laboratories, Ltd. | Ypsilanti, MI | Named on the official list | Public samples: ask the lab | 4/30/2027 (IL ELAP chemistry); Nov 2027 (IDPH microbiology) |
| Pace Analytical National Center for Testing & Innovation TN | Mt. Juliet, TN | Named on the official list | Public samples: ask the lab | 11/30/2027 |
| Pace Analytical Services, LLC - Mansfield fka Alpha Analytical, LLC- Mansfield MA | Mansfield, MA | Named on the official list | Public samples: ask the lab | 6/30/2027 |
| Pace Analytical Services, LLC- Ormond Beach FL | Ormond Beach, FL | Named on the official list | Public samples: ask the lab | 5/31/2027 |
| Pace Analytical Services, LLC. - Minneapolis MN | Minneapolis, MN | Named on the official list | Public samples: ask the lab | 12/31/2026 |
| Pace Analytical Services, LLC.- Peoria | Peoria, IL | Named on the official list | Public samples: ask the lab | 7/31/2027 (IL ELAP chemistry); Jun 2026 (IDPH microbiology) Date on list has passed |
| SGS North America Inc. - Dayton | Dayton, NJ | Named on the official list | Public samples: ask the lab | 6/30/2027 |
| SGS North America Inc. - Scott | Scott, LA | Named on the official list | Public samples: ask the lab | 10/31/2027 |
| Test, Inc. | Peru, IL | Named on the official list | Public samples: ask the lab | 4/30/2027 (IL ELAP chemistry); Nov 2027 (IDPH microbiology) |
| 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 Chicago, Water Purification Laboratories | Chicago, 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) | 7/31/2027 (IL ELAP chemistry); May 2026 (IDPH microbiology) Date on list has passed |
How the Illinois list marks public samples (whole list). Not stated in the lists. IDPH marks each microbiology lab's 'Lab Type' (Commercial, Municipal or Health Department); that is not a statement about homeowners' samples.
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 Illinois
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 Will County, Kankakee County and Kendall County (about 8,733 people in Will 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 |
|---|---|---|
| Will County | 8,733 people (2010 base year) | |
| Kankakee County | 4,374 people (2010 base year) | |
| Kendall County | 3,884 people (2010 base year) | |
| McHenry County | 2,904 people (2010 base year) | |
| Vermilion County | 2,779 people (2010 base year) | |
| Sangamon County | 2,764 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 1,151,113 people in Illinois 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: Illinois.
Other tests in Illinois
- 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)
- IEPA Accredited Laboratories (Primary Labs / Secondary Labs) - Laboratories Accredited for Chemical Analysis + Illinois Department of Public Health - Certified Water Microbiology Laboratories + TNI LAMS fields of accreditation (Drinking Water, accrediting body IL ELAP) (official list)
- IEPA Accredited Laboratories (Primary Labs / Secondary Labs) - Laboratories Accredited for Chemical Analysis + TNI LAMS fields of accreditation (Drinking Water, accrediting body IL ELAP) (official list)
IEPA Accredited Laboratories (Primary Labs / Secondary Labs) - Laboratories Accredited for Chemical Analysis + TNI LAMS fields of accreditation (Drinking Water, accrediting body IL ELAP).
Official source