Short-term kit
PicoCan short-term charcoal canister radon test
- Lab fee included
Method: Charcoal
In home: 48 to 96 hours
Locations and reports
Radon Levels in Grant County, New Mexico
EPA puts Grant County in Zone 2, its middle radon zone, and only 15 radon tests from it are on file with CDC (2008 to 2017, laboratory totals). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Nearest county
16.3%
Doña Ana County, 94 miles
- Doña Ana
- 16.3%
- New Mexico
- 30.3%
Share at 4+ pCi/L, 104 tests, 2006 to 2015
Ground above low
82.2%
10.4 pts below New Mexico
- Grant
- 82.2%
- New Mexico
- 92.6%
Share of land USGS rates moderate or high potential
Tests reported
21
Too few for a share
- Grant
- 21
- Needed
- 30
2005 to 2014, laboratory
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Read a result for Grant County
Starts at EPA's action level
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher.
The data
Grant County, At a glance
Grant County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Grant County is a
USGS geologic potential: Moderate across 82% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Grant County, 2008 to 2017, laboratory
CDC holds 15 reported tests for Grant County over the 2008 to 2017 laboratory totals, with a median of 2.3 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Grant County beside the counties around it is how this page reads it.
What these figures count
Only 15 tests were reported to CDC for Grant County over 2008 to 2017 (laboratory totals), and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Grant County, Compared
Grant County radon figures, compared
Calculated by Radon411CDC's largest figure for Grant County rests on 21 tests over the 2005 to 2014 laboratory totals, 8 of them at or above 4 pCi/L, so each test moves its share by 4.8 points and no rank or comparison is drawn from it. Results reached as high as 7.5 pCi/L, with a middle value of 2.1 pCi/L.
The nearest counties with a figure are Doña Ana County (94 miles away) at 16.3%, Otero County (154 miles away) at 10.7% and Lincoln County (183 miles away) at 20.6%. Pooled across 30 New Mexico counties, 30.3% of reported tests reached that level; across every county in the country with a figure, 36.3%.
Statewide for the same period, Taos County reported the highest share (71.9%) and Otero County the lowest (10.7%). EPA's 1993 map puts Grant County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 82% of the county's land moderate radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Grant County, Geology
The ground under Grant County
PredictedMost of the ground under Grant County is one class on USGS's geologic map: 82.2% of its land is moderate radon potential, with 17.8% low. The map puts 82.2% of Grant County in the area it calls Datil-Mogollon Volcanic Field and 17.8% in Basin and Range Southern Mexican Highland. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 8, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Datil-Mogollon Volcanic Field | Silicic to intermediate volcanic and volcaniclastic rocks, basin-fill gravel, sand, silt. | Moderate | 11 | 82.2% |
| Basin and Range Southern Mexican Highland | Volcanic, plutonic, and lesser sandstone, shale, limestone; Quaternary velley-fill alluvium. | Low | 8 | 17.8% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Grant County beside the ground around it
Across New Mexico 19.2% of the land is rated high; none of Grant County's is. Of the 5 counties that border it, 2 have more high-potential ground, Sierra County the most at 50.4%.
The map rates the ground, not the air in any home.
Local help
Grant County, Local resources
Radon testing and mitigation in Grant County
- New Mexico Indoor Radon Outreach ProgramNew Mexico Indoor Radon Outreach Program, run by New Mexico Environment Department, does not license radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in New Mexico.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The New Mexico Environment Department seasonally distributes free radon testing kits to the public on a first-come, first-served basis.
- Compare kits
- See the New Mexico directoryNo professionals are listed in New Mexico yet. The state program can point you to registered testers and mitigators.
What New Mexico's program says
- Phone
- (505) 476-8600
- radon.questions@env.nm.gov
- Licensing of radon professionals
There is not currently a certification program within the state.
What it means
Grant County, Questions
Questions about radon in Grant County
Are radon levels high in Grant County?
Over the 2008 to 2017 laboratory totals, 46.7% of the radon tests reported to CDC for Grant County, New Mexico were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.3 pCi/L. Of the 8 nearest counties with a figure, within 246 miles, the share of tests at or above 4 pCi/L runs from 10.7% to 41.9%.
Which counties border Grant County?
Grant County borders 5 counties: Luna County, NM, Hidalgo County, NM, Greenlee County, AZ, Sierra County, NM and Catron County, NM.
Products
Grant County, Products
Testing a home in Grant County
No CDC figure names Grant County; the nearest county with one, Doña Ana County (94 miles away), reported 16.3% of its tests at or above 4 pCi/L over the 2006 to 2015 laboratory totals, the only reading nearby until a test of this home. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Grant County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
MonitorX-Sense
XR0A-SR battery digital radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Grant County, Bordering counties
Counties bordering Grant County
Calculated by Radon411- Radon levels in Luna County, NMEPA zone 2
30.0%at or above 4 pCi/L
Median 2.8 pCi/L · 10 tests
- Radon levels in Sierra County, NMEPA zone 2
0.0%at or above 4 pCi/L
Median 1.4 pCi/L · 7 tests
- Radon levels in Catron County, NMEPA zone 2
0.0%at or above 4 pCi/L
Median 3.9 pCi/L · 1 test
- Radon levels in Hidalgo County, NMEPA zone 2
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
- Radon levels in Greenlee County, AZEPA zone 2
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
Grant County, Cities and towns
Cities and towns in Grant County
About 27,252 people live in Grant County by the Census Bureau's estimate for July 1, 2025, 951 fewer than in 2020 (−3.4%). Spread over its land, that is 6.9 people to the square mile. Its largest town, Silver City, has 9,284 residents, 34.1% of the total. Together its 4 incorporated places hold 51.9% of those residents; the other 48.1% live outside any of them. Reported testing is thin here: 21 tests over 2005 to 2014, or 0.8 for every 1,000 residents (2025 estimate), where New Mexico as a whole comes to 2.2.
From Silver City to Hurley, CDC publishes no figure by town: each reads Grant County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Silver City | 9,284 | −4.5% | 34.1% |
| Bayard | 2,048 | −3.3% | 7.5% |
| Santa Clara | 1,592 | −2.6% | 5.8% |
| Hurley | 1,211 | −3.6% | 4.4% |
4 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Grant County, Homes
Homes in Grant County
Of Grant County's 14,664 homes, 62% are detached houses, against 65% across New Mexico; 26% are mobile homes. Half of its homes were built before 1977, close to New Mexico's 1984: 26% date from before 1960 and 14% from 2000 or later. 73% of occupied homes are lived in by their owner (New Mexico: 69%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Grant County | New Mexico |
|---|---|---|
| Housing units | 14,664 | 949,524 |
| Detached houses | 62% | 65% |
| In buildings of 5 or more | 6% | 10% |
| Mobile homes | 26% | 16% |
| Built before 1960 | 26% | 17% |
| Built since 2000 | 14% | 24% |
| Middle year built | 1977 | 1984 |
| Owner-occupied | 73% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.