21 named for arsenic itself on the list.
Per the state list or a state web page. Call to confirm.
Located outside Arizona but on its list.
USGS estimate for Arizona.
How many labs test for arsenic in Arizona
21 labs on Arizona's official drinking-water lab list are certified to test for arsenic. All 21 are named for arsenic on the list. The Arizona list does not say which labs take samples from homeowners, so call a lab before you send one. 14 are located outside Arizona.
The list is published by the Arizona Department of Health Services (ADHS) - Bureau of State Laboratory Services, Office of Laboratory Licensure & Certification (Environmental Laboratory Licensure). List version on file: current as of Saturday, November 7, 2026. Fetched 2026-11-07 (UTC).
Arizona labs certified for arsenic
| Lab | Location | Arsenic certification | Public samples | Cert. expiry |
|---|---|---|---|---|
| A & B Environmental Services, Inc | Houston, TX | Named on the official list | Public samples: ask the lab | Not on the list |
| A & B Labs Arizona Inc. | Tempe, AZ | Named on the official list | Public samples: ask the lab | Not on the list |
| ACZ Laboratories, Inc. | Steamboat Springs, CO | Named on the official list | Public samples: ask the lab | Not on the list |
| AGAT Laboratories | Mississauga, ON | Named on the official list | Public samples: ask the lab | Not on the list |
| AGAT Laboratories | Tempe, AZ | Named on the official list | Public samples: ask the lab | Not on the list |
| ALS Environmental, Kelso | Kelso, WA | Named on the official list | Public samples: ask the lab | Not on the list |
| American Analytical | Tucson, AZ | Named on the official list | Public samples: ask the lab | Not on the list |
| Eurofins Lancaster Laboratories Environment Testing, LLC | Lancaster, PA | Named on the official list | Public samples: ask the lab | Not on the list |
| Eurofins Pomona | Pomona, CA | Named on the official list | Public samples: ask the lab | Not on the list |
| Eurofins South Bend | South Bend, IN | Named on the official list | Public samples: ask the lab | Not on the list |
| Eurofins Tustin | Tustin, CA | Named on the official list | Public samples: ask the lab | Not on the list |
| Legend Technical Services of Arizona, Inc. DBA Legend Analytical | Phoenix, AZ | Named on the official list | Public samples: ask the lab | Not on the list |
| Mohave Environmental Labs | Bullhead City, AZ | Named on the official list | Public samples: ask the lab | Not on the list |
| Motzz Laboratory, Inc. | Phoenix, AZ | Named on the official list | Public samples: ask the lab | Not on the list |
| National Testing Laboratories, LTD. | Ypsilanti, MI | Named on the official list | Public samples: ask the lab | Not on the list |
| Pace Analytical National Center for Testing & Innovation | Mt. Juliet, TN | Named on the official list | Public samples: ask the lab | Not on the list |
| Pace Analytical Services, LLC. - Minneapolis MN | Minneapolis, MN | Named on the official list | Public samples: ask the lab | Not on the list |
| SGS North America Inc. - Dayton | Dayton, NJ | Named on the official list | Public samples: ask the lab | Not on the list |
| SGS North America Inc. - Scott | Scott, LA | Named on the official list | Public samples: ask the lab | Not on the list |
| Turner Laboratories, Inc. | Tucson, AZ | Named on the official list | Public samples: ask the lab | Not on the list |
| WECK Laboratories, Inc. | City of Industry, CA | Named on the official list | Public samples: ask the lab | Not on the list |
How the Arizona list marks public samples (whole list). Not stated per lab. ADHS's private-well pamphlet says independent laboratories can test private well water and points well owners to this list; it does not say which labs take samples from well owners.
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 Arizona
Arsenic is invisible, tasteless and mostly natural, and it comes in two forms that respond very differently to treatment. Read our arsenic explainer.
Arizona guidance that mentions arsenic:
- The Arizona Department of Health Services (ADHS) well owner guide lists a testing schedule. Test all new wells for arsenic, total coliform bacteria, fluoride, lead, nitrates, total dissolved solids (TDS) and uranium. Then test once a year for total coliform bacteria and nitrates, and every 5 years for arsenic, fluoride and uranium. Also test when there are known well water problems in your area, after problems near your well (flooding, wildfire, land disturbances, nearby waste disposal sites), when the water's taste, color or odor changes, or if anyone in your family has an unexplained illness. [1]
USGS estimates that the most private-well users with arsenic above 10 µg/L, EPA's limit for public water, live in Maricopa County, Yavapai County and Yuma County (about 3,884 people in Maricopa 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. [2]
Show the numbers
| Item | Value | Note |
|---|---|---|
| Maricopa County | 3,884 people (2010 base year) | |
| Yavapai County | 3,836 people (2010 base year) | |
| Yuma County | 1,859 people (2010 base year) | |
| Apache County | 1,616 people (2010 base year) | |
| Cochise County | 1,260 people (2010 base year) | |
| La Paz County | 1,044 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 218,170 people in Arizona used private wells in 2015, by the USGS estimate of people on domestic self-supplied water. [3] 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: Arizona.
Other tests in Arizona
- Arizona Department of Health Services, Office of Environmental Health, Protect Your Health: a guide for private well owners in Arizona (no date printed)
- 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)
- ADHS Safe Drinking Water Commercial Lab List (List of Arizona Certified Commercial Drinking Water Laboratories) (official list)
ADHS Safe Drinking Water Commercial Lab List (List of Arizona Certified Commercial Drinking Water Laboratories).
Official source