Arsenic is widespread in Yavapai County wells.
1 widespread, 2 worth checking, 4 rare out of 7 health checks.
From 290 wells tested in Yavapai County since 2000; your own well needs its own test. How to read this
Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+
Lab results: Water Quality Portal (USGS and EPA)
Who drinks from a well here
1 in 3 people 69,599 people
Nobody else tests these wells. Only you do.
People on wells: EPA researchers' 2020 estimate
How deep wells go here
Deep wells: fewer surface germs, more minerals from the rock.
Well depths: US Groundwater Well Database
Radon risk (a gas from rock)
Possible here. A home air test is inexpensive.
Radon zones: EPA map
Here's how Yavapai County compares with Arizona and the counties around it.
Each result puts Yavapai County next to the 5 counties that border it, on the chart's 0 to 50% scale.
This one is widespread in Yavapai County wells.
Arsenic59 of 238 wells over
These 2 are worth checking in Yavapai County.
Nitrate13 of 132 wells over
Manganese19 of 215 wells over
These 4 are rare in Yavapai County.
Fluoride9 of 232 wells over
Uranium1 of 49 wells over
Too few tested to show: Gila, La Paz.
Lead3 of 209 wells over
Radon in water0 of 85 wells over
Too few tested to show: Coconino.
Coliform bacteria turned up in 12 of 41 tested Yavapai County wells, so test for it every year.
Coliform bacteria12 of 41 wells had it
Too few tested to show: Gila, La Paz, Mohave.
E. coli5 of 42 wells had it
Too few tested to show: Gila, La Paz, Mohave.
E. coli means human or animal waste is getting in, so if a test of your Yavapai County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 7 of 195 tested wells, and it isn't a health risk.
Iron stains7 of 195 wells had it
Most of the 290 wells tested in Yavapai County were last tested before 2010.
An old result shows the water as it was then, so treat these 290 wells as a starting point and test your own.
Most Yavapai County wells in these records were tested for research or because someone suspected a problem, which can push the shares above what a typical home well would show (how we read the numbers).
One mail-in lab test covers the 4 things to check in Yavapai County.
- Bacteria
- Nitrate
- Arsenic
- Manganese
What Arizona offers well owners
- Free testingWe didn't find a free program for all of Arizona. Arizona's private well page
- Certified labsArizona's list of certified labs
- Well recordsWe didn't find an online search.
Half the household wells here are shallower than 305 feet.
That comes from 25,043 household wells in Arizona's drilling records. Most wells of every kind here are 179 to 430 feet deep. Wells as deep as Yavapai County's are usually better protected from fertilizer and bacteria at the surface, but they can pick up more of what's in the rock, like arsenic and uranium. Typical household wells here go deeper than in 10 of the 14 other Arizona counties with enough drilling records.
How to find your own well's depth
Well depths: US Groundwater Well Database
Here's what we know about radon and PFAS in Yavapai County.
Yavapai County is in the EPA's middle radon zone. An indoor air test is cheap and tells you whether to look at your water. Radon guide
Between 2023 and 2025 the EPA had 11 town water systems in Yavapai County test for PFAS. 3 of them had at least one test above 4 ng/L, the new EPA limit for PFOA and PFOS. The highest single result was 21 ng/L of PFOA. Only 98 wells in Yavapai County have public PFAS results, so the town systems are the best clue to what's in the groundwater nearby. PFAS guide
Radon zones: EPA Map of Radon Zones. PFAS: EPA tests of town water systems, 2023 to 2025
Questions people ask about well water in Yavapai County
Is well water in Yavapai County safe to drink?
59 of 238 wells tested in Yavapai County had arsenic over the limit, about 1 in 4. Across Arizona it's about 1 in 4. That's a bigger share than in 9 of the 14 other Arizona counties with 10 or more tested wells. So test your own well for arsenic before you count on it.
Where can I get my well tested in Yavapai County?
Use a lab Arizona has certified for drinking water. Arizona's list is linked above, in the box about testing. Ask for bacteria, nitrate, arsenic and manganese, the tests that matter most in Yavapai County.
How deep are wells in Yavapai County?
Half the household wells here are shallower than 305 feet. Typical household wells here go deeper than in 10 of the 14 other Arizona counties with enough drilling records.
How does Yavapai County compare with the counties around it?
For arsenic, the share of tested wells over the limit: 2 of the 5 neighboring counties with data had a higher share than Yavapai County, at 25%. Maricopa had the most, at 34%. Groundwater doesn't stop at county lines, so Maricopa's 34% is worth knowing about if you live near it.
How often should I test my well in Yavapai County?
In Yavapai County, 12 of 41 tested wells had coliform bacteria, so the CDC's advice matters here: test for bacteria and nitrate every year, and right away after a flood, a repair, or any change in taste or smell.
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Where the Yavapai County numbers come from
- People on wells: 69,599 in Yavapai County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 1,832 well water samples from 290 wells in the Water Quality Portal, run by the USGS and EPA, 2000 to 2026.
- Well depths: 25,043 Arizona drilling records for Yavapai County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 5 counties that share a border with Yavapai County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 11 town water systems in Yavapai County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Yavapai County is zone 2 on the EPA Map of Radon Zones.
- State programs and links: Department of Health Services, checked November 1, 2026.