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 Caldwell Parish, Louisiana
EPA puts Caldwell Parish in Zone 3, its lowest radon zone, and only 3 radon tests from it are on file with CDC (2021). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Nearest county
0.0%
East Baton Rouge Parish, 123 miles
- East Baton Rouge Parish
- 0.0%
- Louisiana
- 2.8%
Share at 4+ pCi/L, 48 tests, 2006 to 2015
Ground above low
None
Level with Louisiana
- Caldwell Parish
- 0.0%
- Louisiana
- 0.0%
Share of land USGS rates moderate or high potential
Tests reported
3
Too few for a share
- Caldwell Parish
- 3
- Needed
- 30
2021
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 Caldwell 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
Caldwell Parish, At a glance
Caldwell 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 Caldwell Parish, 2021
CDC holds 3 reported tests for Caldwell Parish in 2021, with a median of 1.0 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Caldwell Parish beside the counties around it is how this page reads it.
What these figures count
Only 3 tests were reported to CDC for Caldwell Parish over 2021, 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. Measured data period: 2021.
Caldwell Parish, Compared
Caldwell Parish radon figures, compared
Calculated by Radon411CDC's largest figure for Caldwell Parish rests on 3 tests in 2021, 0 of them at or above 4 pCi/L, so each test moves its share by 33.3 points and no rank or comparison is drawn from it. Results reached as high as 1.0 pCi/L, with a middle value of 1.0 pCi/L.
The nearest counties with a figure are East Baton Rouge Parish (123 miles away) at 0.0%, Tangipahoa Parish (143 miles away) at 0.0% and Calcasieu Parish (148 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 Caldwell 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.
Caldwell Parish, Geology
The ground under Caldwell Parish
PredictedUSGS's geologic map puts all of Caldwell Parish's mapped land in one class: low radon potential. The map puts 50.1% of Caldwell Parish in the area it calls Floodplain and 49.9% in Old Uplands. USGS gives both a radon index of 7, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Floodplain | Alluvium, marsh, silt, and clay. | Low | 7 | 50.1% |
| Old Uplands | Clays, silts, sands, and ironstone. | Low | 7 | 49.9% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Caldwell Parish beside the ground around it
Neither Caldwell Parish nor Louisiana as a whole has any land USGS rates above low potential. None of the 7 parishes that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Caldwell Parish, Local resources
Radon testing and mitigation in Caldwell 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
Caldwell Parish, Questions
Questions about radon in Caldwell Parish
Are radon levels high in Caldwell Parish?
In 2021, 0.0% of the radon tests reported to CDC for Caldwell Parish, Louisiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.0 pCi/L. Of the 4 nearest counties with a figure, within 198 miles, the share of tests at or above 4 pCi/L runs from 0.0% to 1.5%.
Which counties border Caldwell Parish?
Caldwell Parish borders 7 parishes: Franklin Parish, Ouachita Parish, Richland Parish, Winn Parish, Jackson Parish, LaSalle Parish and Catahoula Parish.
Products
Caldwell Parish, Products
Testing a home in Caldwell Parish
No CDC figure names Caldwell Parish; the nearest county with one, East Baton Rouge Parish (123 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 Caldwell 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
Monitor
Wave Plus battery radon and air quality monitor
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- App only
Method: Alpha spectrometry
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Caldwell Parish, Bordering parishes
Parishes bordering Caldwell Parish
Calculated by Radon411- Radon levels in Franklin ParishEPA zone 3
100.0%at or above 4 pCi/L
Median 5.7 pCi/L · 1 test
- Radon levels in Ouachita ParishEPA zone 3
0.0%at or above 4 pCi/L
Median 2.5 pCi/L · 5 tests
- Radon levels in Richland ParishEPA zone 3
0.0%at or above 4 pCi/L
Median 0.9 pCi/L · 1 test
- 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 Jackson ParishEPA zone 3
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
- Radon levels in LaSalle ParishEPA zone 3
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
- Radon levels in Catahoula ParishEPA zone 3
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
Caldwell Parish, Cities and towns
Cities and towns in Caldwell Parish
About 9,344 people live in Caldwell Parish by the Census Bureau's estimate for July 1, 2025, 272 fewer than in 2020 (−2.8%). That works out to 18 people per square mile of land. No town dominates: Clarks, the largest, has 1,034 residents, 11.1% of the total. Together its 3 incorporated places hold 18.4% of those residents; the other 81.6% live outside any of them. Reported testing is thin here: 3 tests over 2021, or 0.3 for every 1,000 residents (2025 estimate), where Louisiana as a whole comes to 0.7.
From Clarks to Columbia, CDC publishes no figure by town: each reads Caldwell Parish's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Clarks | 1,034 | −1.5% | 11.1% |
| Grayson | 427 | −4.7% | 4.6% |
| Columbia | 262 | −5.4% | 2.8% |
3 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).
Caldwell Parish, Homes
Homes in Caldwell Parish
Mobile homes are 42% of Caldwell Parish's 4,644 homes and detached houses 53%, against 65% across Louisiana. Half of its homes were built before 1988, close to Louisiana's 1982: 14% date from before 1960 and 28% from 2000 or later. 69% of occupied homes are lived in by their owner (Louisiana: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Caldwell Parish | Louisiana |
|---|---|---|
| Housing units | 4,644 | 2,094,002 |
| Detached houses | 53% | 65% |
| In buildings of 5 or more | 1% | 11% |
| Mobile homes | 42% | 13% |
| Built before 1960 | 14% | 19% |
| Built since 2000 | 28% | 27% |
| Middle year built | 1988 | 1982 |
| Owner-occupied | 69% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.