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 St. Charles Parish, Louisiana
EPA puts St. Charles 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
Highest bordering
1.5%
Jefferson Parish
- Jefferson Parish
- 1.5%
1 of 3 neighbours have 30+ tests, 2006 to 2015
Nearest county
1.5%
Jefferson Parish, 16 miles
- Jefferson Parish
- 1.5%
- Louisiana
- 2.8%
Share at 4+ pCi/L, 67 tests, 2006 to 2015
Ground above low
None
Level with Louisiana
- St. Charles Parish
- 0.0%
- Louisiana
- 0.0%
Share of land USGS rates moderate or high potential
Tests reported
24
Too few for a share
- St. Charles Parish
- 24
- Needed
- 30
2019
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 St. Charles 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
St. Charles Parish, At a glance
St. Charles 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 St. Charles Parish, 2021
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2015 | 0.0% |
| 2017 | 0.0% |
| 2018 | 0.0% |
| 2019 | 0.0% |
| 2021 | 0.0% |
2021: 0.0%. Across these years the share ran from 0.0% to 0.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 3 tests were reported to CDC for St. Charles 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. Figure above: 2021. Measured data period: 2005 to 2021 (every CDC figure on file).
St. Charles Parish, Compared
St. Charles Parish radon figures, compared
Calculated by Radon411CDC's largest figure for St. Charles Parish rests on 24 tests in 2019, 0 of them at or above 4 pCi/L, so each test moves its share by 4.2 points and no rank or comparison is drawn from it. Results reached as high as 1.6 pCi/L, with a middle value of 1.1 pCi/L.
Jefferson Parish, the one bordering county with a figure over the 2006 to 2015 laboratory totals, reported 1.5% of its tests at or above 4 pCi/L. Farther out, Tangipahoa Parish (50 miles away) at 0.0%, East Baton Rouge Parish (62 miles away) at 0.0% and Calcasieu Parish (181 miles away) at 0.0% have figures too. 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 St. Charles 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.
St. Charles Parish, Geology
The ground under St. Charles Parish
PredictedUSGS's geologic map puts all of St. Charles Parish's mapped land in one class: low radon potential. All of it lies in the area the map calls Delta, to which USGS gives a radon index of 6, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Delta | Alluvium and marsh. | Low | 6 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
St. Charles Parish beside the ground around it
Neither St. Charles Parish nor Louisiana as a whole has any land USGS rates above low potential. None of the 3 parishes that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
St. Charles Parish, Local resources
Radon testing and mitigation in St. Charles 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
St. Charles Parish, Questions
Questions about radon in St. Charles Parish
Are radon levels high in St. Charles Parish?
In 2021, 0.0% of the radon tests reported to CDC for St. Charles Parish, Louisiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.8 pCi/L. Jefferson Parish, the one bordering county with a figure over the 2006 to 2015 laboratory totals, reported 1.5% of its tests at or above 4 pCi/L.
Which counties border St. Charles Parish?
St. Charles Parish borders 3 parishes: St. John the Baptist Parish, Jefferson Parish and Lafourche Parish.
Products
St. Charles Parish, Products
Testing a home in St. Charles Parish
No CDC figure names St. Charles Parish; the nearest county with one, Jefferson Parish (16 miles away), reported 1.5% 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 St. Charles Parish.
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
St. Charles Parish, Bordering parishes
Parishes bordering St. Charles Parish
Calculated by Radon411- Radon levels in Jefferson ParishEPA zone 3
1.5%at or above 4 pCi/L
Median 0.2 pCi/L · 67 tests
- Radon levels in Lafourche ParishEPA zone 3
0.0%at or above 4 pCi/L
Median 1.0 pCi/L · 1 test
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
St. Charles Parish, Residents
Who lives in St. Charles Parish
About 50,586 people live in St. Charles Parish by the Census Bureau's estimate for July 1, 2025, 1,929 fewer than in 2020 (−3.7%). That works out to 182 people per square mile of land. CDC's 24 reported tests for 2019 work out to 0.5 per 1,000 residents (2025 estimate), close to Louisiana's 0.5.
Census lists no incorporated place in St. Charles Parish: every home in it reads the county's figures.
Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
St. Charles Parish, Homes
Homes in St. Charles Parish
St. Charles Parish is a place of houses on their own lots: 78% of its 20,595 homes are detached single-family houses, against 65% across Louisiana. Half of its homes were built before 1986, close to Louisiana's 1982: 11% date from before 1960 and 24% from 2000 or later. Owners live in 83% of the occupied homes (Louisiana: 67%), so for most households a test and a fix are their own to order.
| Homes | St. Charles Parish | Louisiana |
|---|---|---|
| Housing units | 20,595 | 2,094,002 |
| Detached houses | 78% | 65% |
| In buildings of 5 or more | 4% | 11% |
| Mobile homes | 11% | 13% |
| Built before 1960 | 11% | 19% |
| Built since 2000 | 24% | 27% |
| Middle year built | 1986 | 1982 |
| Owner-occupied | 83% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.