Manganese and nitrate are widespread in Valencia County wells.
2 widespread, 1 worth checking, 3 rare out of 6 health checks.
From 17 wells tested in Valencia County since 2001; your own well needs its own test. How to read this
Not charted, because fewer than 10 wells were tested: radon (3).
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 27,191 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 Valencia County compares with New Mexico and the counties around it.
Each result puts Valencia County next to the 4 counties that border it, on the chart's 0 to 50% scale.
These 2 are widespread in Valencia County wells.
Manganese5 of 10 wells over
Too few tested to show: Socorro, Torrance.
Nitrate4 of 17 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Socorro, Torrance.
This one is worth checking in Valencia County.
Arsenic1 of 10 wells over
Too few tested to show: Socorro, Torrance.
These 3 are rare in Valencia County.
Uranium0 of 10 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Socorro, Torrance.
Fluoride0 of 12 wells over
Too few tested to show: Socorro, Torrance.
Lead0 of 10 wells over
Too few tested to show: Socorro, Torrance.
Too few Valencia County wells were tested for this one.
Radon in water3 wells tested
Coliform bacteria turned up in 1 of 3 tested Valencia County wells, so test for it every year.
Coliform bacteria1 of 3 wells had it
E. coli0 of 3 wells had it
E. coli means human or animal waste is getting in, so if a test of your Valencia County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 2 of 10 tested wells, and it isn't a health risk.
Iron stains2 of 10 wells had it
Too few tested to show: Socorro, Torrance.
Valencia County has 17 tested wells, and the busiest decade for testing was the 2000s.
None of the 17 wells has a test from 2020 or later, so a fresh test of your own well tells you more than any of these.
Most Valencia 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 Valencia County.
- Bacteria
- Nitrate
- Manganese
- Arsenic
What New Mexico offers well owners
- Free testingNMED offers free well water screening at water fairs and limited free nitrate, iron and fluoride screening at some field offices; these do not replace certified lab tests. See the program
- Certified labsNew Mexico's list of certified labs
- Well recordsNew Mexico's well record search
Half the household wells here are shallower than 175 feet.
That comes from 9,767 household wells in New Mexico's drilling records. Most wells of every kind here are 100 to 210 feet deep. Wells as deep as Valencia 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 are shallower than in 17 of the 31 other New Mexico counties with enough drilling records.
Look up your own well's depth in New Mexico's well record search, or see how to find it.
Well depths: US Groundwater Well Database
Here's what we know about radon and PFAS in Valencia County.
Valencia 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 4 town water systems in Valencia County test for PFAS. 1 found some PFAS, all below the new limits. Only 5 wells in Valencia 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 Valencia County
Is well water in Valencia County safe to drink?
5 of 10 wells tested in Valencia County had manganese over the limit, about 5 in 10. Across New Mexico it's about 2 in 10. That's the highest share among the 14 New Mexico counties with 10 or more tested wells, leaving out 1 county whose results are likely overstated. So test your own well for manganese before you count on it.
Can I get my well tested for free in Valencia County?
NMED offers free well water screening at water fairs and limited free nitrate, iron and fluoride screening at some field offices; these do not replace certified lab tests. If not, use a lab New Mexico has certified for drinking water. Ask for bacteria, nitrate, manganese and arsenic, the tests that matter most in Valencia County.
How deep are wells in Valencia County?
Half the household wells here are shallower than 175 feet. Typical household wells here are shallower than in 17 of the 31 other New Mexico counties with enough drilling records.
How does Valencia County compare with the counties around it?
For manganese, the share of tested wells over the limit: Valencia County, at 50%, had a higher share than all 2 neighboring counties with data. Groundwater doesn't stop at county lines, so Bernalillo's 14% is worth knowing about if you live near it.
How often should I test my well in Valencia County?
In Valencia County, 1 of 3 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 Valencia County numbers come from
- People on wells: 27,191 in Valencia County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 122 well water samples from 17 wells in the Water Quality Portal, run by the USGS and EPA, 2001 to 2017.
- Well depths: 9,767 New Mexico drilling records for Valencia County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 4 counties that share a border with Valencia County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 4 town water systems in Valencia County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Valencia County is zone 2 on the EPA Map of Radon Zones.
- State programs and links: Environment Department, checked November 1, 2026.