Well water in Greenlee County, Arizona
1in4
Testing strongly recommended
tested well samples in Greenlee County exceeded the EPA limit for arsenic (10 ug/L), based on public data from USGS Water Quality Portal.
980 test results across 11 contaminants from at least 78 wells, 1952 to 2014; chloride has the most at 144. Data refreshed September 15, 2026.
Compiled by Nick at Well Water Nerd from public records. How these pages are built
An estimated 1,350 people in Greenlee County get their drinking water from a private well, per USGS 2015 county water use. That is about 14% of residents.
Separately, the USGS national arsenic model estimates that 9% of the 1,350 people on private wells in Greenlee County draw water above 10 ug/L (the model's range is 7% to 12%), from geology and well depth rather than local tests.
What individual samples found
Each row summarizes every public sample for that contaminant inside Greenlee County. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.
| Contaminant | Above limit | Samples | Detected | Median | Highest | Limit |
|---|---|---|---|---|---|---|
| Arsenic 1985 to 2014 | 79 | 42% | 0 | 85 | 10 ug/L EPA limit | |
| Fluoride 1952 to 2014 | 135 | 96% | 1.3 | 11 | 4 mg/L EPA limit | |
| Nitrate 1952 to 2014 | 90 | 98% | 1 | 22 | 10 mg/L EPA limit | |
| Copper 1985 to 2014 | 77 | 16% | 0 | 0.04 | 1.3 mg/L EPA limit | |
| Lead 1985 to 2014 | 77 | 3% | 0 | 10 | 15 ug/L EPA limit | |
| Chloride 1952 to 2014 | no limit | 144 | 100% | 17 | 1,800 | 250 mg/L nuisance level |
| Iron 1956 to 2014 | no limit | 126 | 40% | 0 | 3,600 | 300 ug/L nuisance level |
| Sodium 1973 to 2014 | no limit | 123 | 100% | 44 | 1,300 | 20 mg/L health guideline |
| Manganese 1973 to 2014 | no limit | 108 | 21% | 0 | 800 | 300 ug/L health guideline |
| Radon 2001 | no limit | 13 | 100% | 370 | 1,270 | 2,000 pCi/L health guideline |
Sampled fewer than 10 times, too few to summarize: Radium (226 + 228) (8).
Over time
Share of samples above the limit by period. A cell needs ten samples to show; a comparison needs twenty in each period. Later periods sample fewer wells, and often the ones already known to have a problem.
| Contaminant | before 2000 | 2000s | 2010s | 2020s |
|---|---|---|---|---|
| Fluoride | 6%93 samples | 10%40 samples | n/a | n/a |
| Nitrate | 1%78 samples | 10%10 samples | n/a | n/a |
| Arsenic | 33%40 samples | 22%37 samples | n/a | n/a |
| Copper | 0%38 samples | 0%37 samples | n/a | n/a |
| Lead | 0%38 samples | 0%37 samples | n/a | n/a |
Arsenic above the limit in Greenlee County fell from 33% of 40 samples before 2000 to 22% of 37 in the 2000s.
Fluoride, copper, lead have held within a few points between the two most recent periods with enough samples.
Closer than the county
See the sampled wells near your address
The same records, drawn around one point: which wells within a few miles were sampled and what they found, how deep the wells next to you were drilled, and any leaking tank or cleanup site within a mile.
Check my addressWhat this means
The contaminants most often above their limit here are arsenic (27% of 79 samples), fluoride (7% of 135 samples), and nitrate (2% of 90 samples). A well next door can differ sharply from yours because bedrock fractures, well depth and plumbing all matter, so these rates describe the area, not your tap.
Chloride is widespread in local groundwater. It is mainly a staining and taste problem, but high manganese also carries a health advisory for infants.
What to test for in Greenlee County
- 1Arsenic27% of 79 local samples were above the limit.
- 2Fluoride7% of 135 local samples were above the limit.
- 3Nitrate2% of 90 local samples were above the limit.
- 4Coliform bacteriaRecommended for every private well, every year.
- 5RadonMedian local reading is 370 pCi/L.
- 6ChlorideDetected in 100% of local samples.
- 7Volatile organic compounds (VOCs)22 leaking underground storage tank sites on record locally.
Test your Greenlee County well for arsenic, fluoride and nitrate
Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.
Order the Tap Score well water test kit, from $209Already tested? Upload the report
Just want bacteria checked first? Tap Score coliform and E. coli test, $99. Coliform and E. coli are the tests every well needs every year.
Want a quick look before paying for a lab? Home well water test strips on Amazon check hardness, iron, pH and nitrate in minutes. They are a screen, not a result: arsenic, bacteria, uranium and PFAS need a certified lab.
Affiliate links: the merchant pays us a commission and the price is the same for you. It does not change what the data above says. As an Amazon Associate we earn from qualifying purchases.
Where to get a well tested in Arizona: certified labs, state programs and prices.
Already have results back? Get your lab report read against the Greenlee County numbers, $29. Every line explained, ranked by what matters, with the fix for each.
Wells in Greenlee County
1,288 domestic wells in Greenlee County are on record with the state since 1970. the typical well is 131 feet deep (one in ten goes past 399 feet).
In a typical Greenlee County well, the median yield is 25 gallons per minute, 2% of wells yield under 3 gallons per minute and usually need a storage tank.
Find your own well's report
The state keeps the driller's report for most wells drilled since 1984. It tells you how deep your well is, where bedrock starts, and how much water it makes, which decides what treatment can work.
- Open ADWR Wells55 registry and choose Water Well.
- The record lists depth, water level, casing depth and the tested rate, plus a link to the drilling log.
Arizona has registered wells since 1980; earlier wells often have no record.
The rock under Greenlee County
Not a principal aquifer
The USGS map places this area outside any principal aquifer, which usually means wells here draw from fractured bedrock or thin local deposits rather than a large regional aquifer. Bedrock wells of that kind are where arsenic, radon and uranium turn up, and yields vary from well to well.
Classification from the USGS Principal Aquifers of the United States (national map, 2003 edition, GIS release 2015), read at the county centroid. A single well can sit in a different unit, especially near a boundary.
Official help in Arizona
Two places to start that are not selling anything: the state program that answers private well questions, and its list of labs certified to run drinking water tests. A certified lab is the difference between a result you can act on and a number.
Contamination sources on record in Greenlee County
ADEQ records 22 leaking underground storage tank sites in Greenlee County, among 23 regulated sites in total. Groundwater does not follow property lines, so a well within a few hundred feet of one of these is worth testing for what that site could release.
- 22
- leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
- 1
- lined landfill or transfer facility
Treatment that fits the local profile
Arsenic
Point-of-use reverse osmosis; Adsorptive media (iron-based) whole-house; Anion exchange
Fluoride
Point-of-use reverse osmosis; Activated alumina; Distillation
Nitrate
Point-of-use reverse osmosis; Anion exchange; Distillation
Systems we would look at first
Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.
For arsenic
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For arsenic
Whole-house arsenic and uranium filter
whole-house, at the point of entry, about $2,500
Adsorptive iron-based media; sized to your well yield.
For arsenic
Aquasana SmartFlow reverse osmosis
under-sink or countertop, about $225
Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.
Free, no obligation
Get on the list for a free in-home water test in Greenlee County
No water treatment company serves Greenlee County through Well Water Nerd yet. We are signing licensed companies on county by county: they test at your tap for free, walk you through the numbers, and quote treatment only if something needs fixing. Leave your details and you are first in line. Nothing is shared until a company joins for Greenlee County, and you get an email naming it first.
Common questions
How deep are wells in Greenlee County?
The typical domestic well in Greenlee County is 131 feet deep, based on 1,288 wells reported to the state since 1970. One in ten is deeper than 399 feet.
Is there arsenic in well water in Greenlee County?
Arsenic was detected in 42% of 79 public well samples in Greenlee County, and 27% were above the EPA limit of 10 ug/L. Arsenic has no taste or smell; a lab test is the only way to know your level.
How high is radon in well water in Greenlee County?
The median radon level across 13 public samples in Greenlee County was 370 pCi/L, with a high of 1,270 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.
How often should I test a private well in Greenlee County?
Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.
Counties near Greenlee County
Closest first. Groundwater does not stop at a line on a map, so the next county over is a fair second opinion.
Want the numbers themselves? Download the Arizona dataset as CSV, every county and town, with the sources named.
Sources
- USGS Water Quality Portal: 980 samples in Greenlee County. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
- USGS national arsenic model (Ayotte 2017): estimated share of 1,350 people on private wells in Greenlee County above 10 ug/L of arsenic, from geology, well depth and land use. County estimates of domestic well users with arsenic above 10 ug/L from the USGS national logistic regression model (Ayotte, Medalie and Qi, 2017), with private well population from the USGS 2015 county water-use compilation (Dieter and others, 2018). Retrieved September 15, 2026.
- Arizona ADWR well registry (Wells55): 3,295 well records in Greenlee County, 1,288 domestic. Registered wells from the Arizona Department of Water Resources Wells55 registry. Only aggregates are shown; owner names and addresses are never stored. Retrieved September 18, 2026.
- ADEQ regulated sites: 23 regulated sites located in Greenlee County. Leaking underground storage tank sites and municipal landfills from the Arizona Department of Environmental Quality. Retrieved September 18, 2026.
Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.