Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Grant Parish, Louisiana
EPA puts Grant Parish in Zone 3, its lowest radon zone, and only 2 radon tests from it are on file with CDC (2006 to 2015, laboratory totals). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Nearest county
0.0%
Calcasieu Parish, 106 miles
- Calcasieu Parish
- 0.0%
- Louisiana
- 2.8%
Share at 4+ pCi/L, 59 tests, 2006 to 2015
Ground above low
None
Level with Louisiana
- Grant Parish
- 0.0%
- Louisiana
- 0.0%
Share of land USGS rates moderate or high potential
Tests reported
2
Too few for a share
- Grant Parish
- 2
- Needed
- 30
2006 to 2015, laboratory
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Grant Parish
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 Parish, At a glance
Grant Parish at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Grant Parish, 2006 to 2015, laboratory
CDC holds 2 reported tests for Grant Parish over the 2006 to 2015 laboratory totals, with a median of 3.9 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Grant Parish beside the counties around it is how this page reads it.
What these figures count
Only 2 tests were reported to CDC for Grant Parish over 2006 to 2015 (laboratory totals), and tests are often run on homes being sold or already suspected of a problem: so few describe neither the parish nor this house.
Measured: CDC tracking data. Figure above: 2006 to 2015, laboratory. Measured data period: 2005 to 2015 (every CDC figure on file).
Grant Parish, Compared
Grant Parish radon figures, compared
Calculated by Radon411CDC's largest figure for Grant Parish rests on 2 tests over the 2006 to 2015 laboratory totals, 0 of them at or above 4 pCi/L, so each test moves its share by 50.0 points and no rank or comparison is drawn from it. Results reached as high as 3.9 pCi/L, with a middle value of 3.9 pCi/L.
The nearest counties with a figure are Calcasieu Parish (106 miles away) at 0.0%, East Baton Rouge Parish (114 miles away) at 0.0% and Tangipahoa Parish (144 miles away) at 0.0%. Pooled across 37 Louisiana counties, 2.8% of reported tests reached that level; across every county in the country with a figure, 36.3%.
Statewide for the same period, Jefferson Parish reported the highest share (1.5%) and Tangipahoa Parish the lowest (0.0%). EPA's 1993 map puts Grant Parish in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 100% of the county's land low radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Grant Parish, Geology
The ground under Grant Parish
PredictedUSGS's geologic map puts all of Grant Parish's mapped land in one class: low radon potential. The map puts 50.3% of Grant Parish in the area it calls Terraces and Prairies and 49.5% in Old Uplands. USGS gives the first a radon index of 8 and the second 7, both in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Terraces and Prairies | Clay, sandy clay, silt, sand, and some gravel. | Low | 8 | 50.3% |
| Old Uplands | Clays, silts, sands, and ironstone. | Low | 7 | 49.5% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Grant Parish beside the ground around it
Neither Grant Parish nor Louisiana as a whole has any land USGS rates above low potential. None of the 4 parishes that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Grant Parish, Local resources
Radon testing and mitigation in Grant Parish
- Louisiana's radon programLouisiana Department of Environmental QualityLouisiana's radon program answers questions about testing, mitigation and the rules in Louisiana.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- See the Louisiana directoryNo professionals are listed in Louisiana yet. The state program can point you to registered testers and mitigators.
What it means
Grant Parish, Questions
Questions about radon in Grant Parish
Are radon levels high in Grant Parish?
Over the 2006 to 2015 laboratory totals, 0.0% of the radon tests reported to CDC for Grant Parish, Louisiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.9 pCi/L. Of the 4 nearest counties with a figure, within 191 miles, the share of tests at or above 4 pCi/L runs from 0.0% to 1.5%.
Which counties border Grant Parish?
Grant Parish borders 4 parishes: LaSalle Parish, Winn Parish, Rapides Parish and Natchitoches Parish.
Products
Grant Parish, Products
Testing a home in Grant Parish
No CDC figure names Grant Parish; the nearest county with one, Calcasieu Parish (106 miles away), reported 0.0% 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. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Grant Parish.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
MonitorForensics Detectors
FD-65-RADON rechargeable radon detector with a color screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 6 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Grant Parish, Bordering parishes
Parishes bordering Grant Parish
Calculated by Radon411- Radon levels in Winn ParishEPA zone 3
0.0%at or above 4 pCi/L
Median 1.1 pCi/L · 1 test
- Radon levels in Rapides ParishEPA zone 3
0.0%at or above 4 pCi/L
Median 0.8 pCi/L · 4 tests
- Radon levels in Natchitoches ParishEPA zone 3
0.0%at or above 4 pCi/L
Median 0.5 pCi/L · 4 tests
- Radon levels in LaSalle ParishEPA zone 3
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
Grant Parish, Cities and towns
Cities and towns in Grant Parish
Grant Parish's population has barely moved since 2020: 22,075 residents on July 1, 2025 against 22,150 then, by the Census Bureau's estimates. That works out to 34 people per square mile of land. No town dominates: Colfax, the largest, has 1,393 residents, 6.3% of the total. Together its 6 incorporated places hold 15.6% of those residents; the other 84.4% live outside any of them. CDC's 2 reported tests for 2006 to 2015 work out to 0.1 per 1,000 residents (2025 estimate), close to Louisiana's 0.1.
From Colfax to Georgetown, CDC publishes no figure by town: each reads Grant Parish's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Colfax | 1,393 | −2.7% | 6.3% |
| Montgomery | 628 | +0.2% | 2.8% |
| Dry Prong | 443 | −2.6% | 2.0% |
| Pollock | 393 | −2.2% | 1.8% |
| Creola | 309 | +28.2% | 1.4% |
| Georgetown | 276 | −0.4% | 1.3% |
6 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 Parish, Homes
Homes in Grant Parish
Of Grant Parish's 9,054 homes, 63% are detached houses, against 65% across Louisiana; 33% are mobile homes. Half of its homes were built before 1989, close to Louisiana's 1982: 17% date from before 1960 and 32% from 2000 or later. Owners live in 82% of the occupied homes (Louisiana: 67%), so for most households a test and a fix are their own to order.
| Homes | Grant Parish | Louisiana |
|---|---|---|
| Housing units | 9,054 | 2,094,002 |
| Detached houses | 63% | 65% |
| In buildings of 5 or more | 1% | 11% |
| Mobile homes | 33% | 13% |
| Built before 1960 | 17% | 19% |
| Built since 2000 | 32% | 27% |
| Middle year built | 1989 | 1982 |
| Owner-occupied | 82% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.