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Radon Levels in Richland Parish, Louisiana

EPA puts Richland Parish in Zone 3, its lowest radon zone, and only 1 radon test from it is 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

How to test this homeFind a certified tester

  • Nearest county

    0.0%

    East Baton Rouge Parish, 135 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

    Richland Parish
    0.0%
    Louisiana
    0.0%

    Share of land USGS rates moderate or high potential

  • Tests reported

    1

    Too few for a share

    Richland Parish
    1
    Needed
    30

    2008 to 2017, laboratory

  • EPA radon zone

    Zone 3

    Lower potential

    1. 1
    2. 2
    3. Zone 3

    1 highest, 3 lowest

    EPA predicts under 2 pCi/L indoors

Read a result for Richland Parish

Starts at EPA's action level

4.0pCi/L

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

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 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.

Interpret this readingWhat a fix costs

The data

Richland Parish, At a glance

Richland Parish at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Richland Parish as a whole is an average indoor of less than 2 pCi/L (less than 75 Bq/m³). A low zone clears no address in it: homes above EPA's turn up in all three zones.

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 Richland Parish, 2008 to 2017, laboratory

CDC holds 1 reported test for Richland Parish over the 2008 to 2017 laboratory totals, a result of 0.9 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Richland Parish beside the counties around it is how this page reads it.

What these figures count

Only 1 test was reported to CDC for Richland Parish 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 parish nor this house.

Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).

How to read these figures

Richland Parish, Compared

Richland Parish radon figures, compared

Calculated by Radon411

CDC's largest figure for Richland Parish rests on 1 test over the 2008 to 2017 laboratory totals, 0 of them at or above 4 pCi/L, so each test moves its share by 100.0 points and no rank or comparison is drawn from it. Results reached as high as 0.9 pCi/L, with a middle value of 0.9 pCi/L.

The nearest counties with a figure are East Baton Rouge Parish (135 miles away) at 0.0%, Tangipahoa Parish (147 miles away) at 0.0% and Calcasieu Parish (178 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 Richland 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.

Louisiana, the United States and the counties around Richland Parish, 2006 to 2015, laboratory
AreaTestsAt or above 4 pCi/LMedian
Louisiana, pooled37 counties, pooled4342.8%Not pooled
United States, pooled2,669 counties, pooled1,805,52836.3%Not pooled
Jefferson Parishhighest in the state671.5%0.2 pCi/L
Tangipahoa Parishlowest in the state430.0%0.1 pCi/L
Franklin Parish, LAborders it1100.0%5.7 pCi/L
Ouachita Parish, LAborders it50.0%2.5 pCi/L
The nearest Louisiana counties to Richland Parish with 30 or more tests, 2006 to 2015, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
East Baton Rouge Parish135 mi480.0%0.6 pCi/L
Tangipahoa Parish147 mi430.0%0.1 pCi/L
Calcasieu Parish178 mi590.0%0.2 pCi/L
Jefferson Parish206 mi671.5%0.2 pCi/L
Richland Parish ten-year laboratory totals, against Louisiana's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestLouisiana, pooledChange from the row before
2008 to 201710.0%0.9 pCi/L0.9 pCi/L2.2%Level
2007 to 201610.0%0.9 pCi/L0.9 pCi/L2.6%Level
2006 to 201510.0%0.9 pCi/L0.9 pCi/L2.8%Level
2005 to 201410.0%0.9 pCi/L0.9 pCi/L2.6%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Richland Parish, Geology

The ground under Richland Parish

Predicted

USGS's geologic map puts all of Richland Parish's mapped land in one class: low radon potential. All of it lies in the area the map calls Floodplain, to which USGS gives a radon index of 7, in the low band (5 to 8).

USGS's geologic areas under Richland Parish
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
FloodplainAlluvium, marsh, silt, and clay.Low7100%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Richland Parish beside the ground around it

Neither Richland 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.

Share of land by USGS radon potential: Richland Parish, the 7 parishes bordering it and Louisiana
AreaEPA zoneLow potentialModerate potentialHigh potential
Richland ParishZone 3100%NoneNone
Franklin ParishZone 3100%NoneNone
Morehouse ParishZone 3100%NoneNone
Ouachita ParishZone 3100%NoneNone
Caldwell ParishZone 3100%NoneNone
Madison ParishZone 3100%NoneNone
West Carroll ParishZone 3100%NoneNone
East Carroll ParishZone 3100%NoneNone
Louisiana64 parishes, pooled by land areaVaries98.4%NoneNone

The map rates the ground, not the air in any home.

Local help

Richland Parish, Local resources

Radon testing and mitigation in Richland Parish

What it means

Richland Parish, Questions

Questions about radon in Richland Parish

Are radon levels high in Richland Parish?

Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Richland Parish, Louisiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.9 pCi/L. Of the 4 nearest counties with a figure, within 206 miles, the share of tests at or above 4 pCi/L runs from 0.0% to 1.5%.

Which counties border Richland Parish?

Richland Parish borders 7 parishes: Franklin Parish, Morehouse Parish, Ouachita Parish, Caldwell Parish, Madison Parish, West Carroll Parish and East Carroll Parish.

Products

Richland Parish, Products

Testing a home in Richland Parish

No CDC figure names Richland Parish; the nearest county with one, East Baton Rouge Parish (135 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 Richland Parish.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Richland Parish homes, compared

Explore

Richland Parish, Bordering parishes

Parishes bordering Richland Parish

Calculated by Radon411

Richland Parish, Cities and towns

Cities and towns in Richland Parish

About 19,582 people live in Richland Parish by the Census Bureau's estimate for July 1, 2025, 447 fewer than in 2020 (−2.2%). That works out to 35 people per square mile of land. No town dominates: Rayville, the largest, has 3,176 residents, 16.2% of the total. Together its 3 incorporated places hold 32.2% of those residents; the other 67.8% live outside any of them. Reported testing is thin here: 1 test over 2008 to 2017, or 0.1 for every 1,000 residents (2025 estimate), where Louisiana as a whole comes to 0.1.

From Rayville to Mangham, CDC publishes no figure by town: each reads Richland Parish's.

The cities and towns in Richland Parish by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Rayville3,176−5.0%16.2%
Delhi2,519−3.9%12.9%
Mangham609−2.7%3.1%

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).

Richland Parish, Homes

Homes in Richland Parish

Of Richland Parish's 8,698 homes, 69% are detached houses, against 65% across Louisiana; 24% are mobile homes. Half of its homes were built before 1979, close to Louisiana's 1982: 17% date from before 1960 and 25% from 2000 or later. 67% 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 in Richland Parish, Louisiana, 2019 to 2023
HomesRichland ParishLouisiana
Housing units8,6982,094,002
Detached houses69%65%
In buildings of 5 or more1%11%
Mobile homes24%13%
Built before 196017%19%
Built since 200025%27%
Middle year built19791982
Owner-occupied67%67%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.