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Radon Levels in St. Mary Parish, Louisiana

EPA puts St. Mary Parish in Zone 3, its lowest radon zone. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

Predicted
Zone 3Lower predicted potential
Measured
0.0%of 54 tests reported to CDC (2018) were at or above 4 pCi/L
Your home
Test to knowNo area figure here is a reading of your home.
How to test this homeFind a certified tester

The data

St. Mary Parish, At a glance

St. Mary Parish at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

This is a county-level geologic prediction. It is not a measurement of any address, and houses with elevated radon are found in all three zones.

What EPA predicts hereScreening level, geology

EPA predicts an average indoor of less than 2 pCi/L (less than 75 Bq/m³) across the parish as a whole.

USGS geologic potential: Low across 93% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for St. Mary Parish, 2018

Tests reported
54
At or above 4 pCi/L
0.0%
Median result
0.4 pCi/L
Reported results by concentration band, St. Mary Parish, 2018
Under 2 pCi/L: 100%2 to 4 pCi/L: 0%4 pCi/L and above: 0%

Of 54 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, St. Mary Parish, 2018: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L54100.0%
2 to 4 pCi/L00.0%
4 pCi/L and above00.0%

CDC publishes this figure only for counties here, so there is no state or national number to compare St. Mary Parish, Louisiana with.

What these figures count

Distribution of radon tests reported to CDC, not this house. People testing before a sale, or because they suspect a problem, are over-represented in any reported testing data.

The figures at the top are for 2018: a percentage there is a share of radon tests reported to CDC for St. Mary Parish in 2018, and a percentage in a view below is a share of the tests reported for the year or period it names. It is not a share of homes in St. Mary Parish, and it is not a random sample: it counts only the tests people chose to run and that were reported.

CDC works out the shares and the median over pre-mitigation tests, counting a test not marked as before or after mitigation as one of them (54 for 2018). The median is the middle result of those tests, not of buildings. CDC also reports the number of buildings tested (1), a different count, so the two totals are not interchangeable.

St. Mary Parish's own published CDC figures beside those of the counties that border it, for the same period.

Each figure is that county’s own published CDC figure for 2018, counting radon tests reported to CDC, not homes. St. Mary Parish is this page. Nothing is averaged or combined across counties. The test count beside each county is CDC’s published number of pre-mitigation tests behind its figures. Figures from few tests can swing widely from year to year. No published CDC figure for 2018: Assumption Parish, LA; Iberia Parish, LA; St. Martin Parish, LA. Every Louisiana county’s own figure is in the Louisiana county table.

Measured: CDC tracking data. Figure above: 2018. Measured data period: 2016 to 2018 (every CDC figure on file).

Radon Action Brief

National Radon Action MonthPre-sale

St. Mary Parish's radon brief, in one dated file.

  • Your area's radon record, explained.
  • Your plan to test this week.
  • Fix costs and pros near you.

Save 64%Sale price: $8.99Price after the sale: $25Ends Jan 31Then $25

Get the St. Mary Parish BriefSee a free sample

Area data, not a test of the building.

Local help

St. Mary Parish, Local resources

Radon testing and mitigation in St. Mary Parish

Who tests and fixes radon in St. Mary Parish: listed businesses, Louisiana's radon program and test kits.

What it means

St. Mary Parish, Questions

Questions about radon in St. Mary Parish

Common questions

8 questions, answered from the figures above

Are radon levels high in St. Mary Parish?

In 2018, 0.0% of the radon tests reported to CDC for St. Mary Parish, Louisiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.4 pCi/L. That is a share of reported tests, not of homes. EPA places St. Mary Parish in Zone 3, lower predicted potential, a predicted average indoor screening level less than 2 pCi/L. Homes with elevated levels occur in all three zones, so the figures describe the area, not your house. Testing is the only way to know the radon level in a specific building.

Radon levels: what a result meansWhat is radon?Radon levels in Louisiana

How do I get a radon test in St. Mary Parish?

EPA says you can test your home yourself or hire a qualified radon test company, and that either approach takes only a small amount of time and effort. No radon testing business listed on Radon411 has an address in St. Mary Parish or names it as a service area yet. The Louisiana radon program is the place to ask about certified testers and any test kit offer it runs.

Radon testing: how to test a homeRadon test kits comparedFree and low-cost kits by stateRadon Action Month checklistLouisiana radon program

Who does radon mitigation in St. Mary Parish?

Radon411 has no radon business listed for Louisiana yet. EPA recommends having a qualified contractor fix a home with a radon problem, because lowering high radon levels takes technical knowledge and special skills, and some states require the work to be done by a licensed or certified professional. Your state radon program is the place to check whether Louisiana requires one.

Radon mitigation: how it worksRadon mitigation costRadon mitigation systemsLouisiana radon program

What EPA radon zone is St. Mary Parish in?

EPA places St. Mary Parish, Louisiana in Zone 3, which EPA describes as lower predicted potential for the area. A zone is a prediction for the whole county and never determines whether a particular home should be tested. EPA recommends testing every home regardless of zone.

Should I test my home in St. Mary Parish?

Yes. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. How to test a home.

When is the best time of year to test?

EPA says short-term tests stay in the home from 2 to 90 days and that all radon tests should run a minimum of 48 hours; long-term tests stay more than 90 days. EPA's guides do not name a best season: they say radon levels tend to vary from day to day and season to season, so a long-term test is more likely than a short-term test to tell you the year-round average.

What does it cost to test?

EPA's Citizen's Guide calls testing easy and inexpensive, and EPA's Home Buyer's and Seller's Guide says passive short-term and long-term devices are generally inexpensive, while active devices may cost more. No national average price is published for this, so Radon411 does not give one. What testing costs.

Which counties border St. Mary Parish?

St. Mary Parish borders 4 parishes, derived from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county's report can be relevant.

If you own, buy, sell or rent

What these figures mean for each reader, with the guide that covers it

The reported-test figures on this page describe St. Mary Parish, Louisiana in 2018. They describe tests other people carried out in other buildings, and none of them measures yours.

St. Mary Parish in figures

The figures above, said in words

What the published data says about St. Mary Parish, in words. A zone and a share of tests describe an area, never the level in any one home.

    • Predicted

      Predicted

      EPA places St. Mary Parish in Zone 3, lower predicted potential, as it does 63 other parishes of Louisiana's 64.

      Of the 4 bordering parishes, EPA places Assumption Parish, Iberia Parish, St. Martin Parish and Terrebonne Parish in Zone 3.

  • Reported tests

    Measured

    CDC has annual figures for St. Mary Parish for 2 years, 2016 to 2018. In 2018, 0.0% of 54 reported tests were at or above 4 pCi/L.

  • Local record

    Louisiana's radon program and its page are under Local resources.

    The county's largest incorporated places are Morgan City, Franklin and Patterson; the figures here cover them as part of the county.

Products

St. Mary Parish, Products

Testing and mitigation products

Whatever the figures for St. Mary Parish show, only a test tells you about one home.

Test kits and monitors42

See all products

As an Amazon Associate, Radon411 earns from qualifying purchases.

Best radon monitors for St. Mary Parish homes, compared

Testing

5

Mitigation

3

Explore

St. Mary Parish, Bordering parishes

Parishes bordering St. Mary Parish

Calculated by Radon411
Why bordering counties matter

4 parishes share a boundary with St. Mary Parish, computed from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county’s report can be worth reading alongside this one.

St. Mary Parish, Cities and towns

Cities and towns in St. Mary Parish

The radon figures on this page are for St. Mary Parish as a whole. They do not differ by city or town.

  • Morgan City (part)
  • Franklin
  • Patterson
  • Berwick
  • Baldwin

5 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county.

St. Mary Parish, Next steps

What to do next

  1. LearnKnow what radon isWhat radon is, how it gets indoors, and why a county zone is not a reading for your home.Learn about radon
  2. TestTest the building you live inShort-term or long-term, where the device goes, and closed-house conditions.How to test
  3. FixBring a high level downHow a mitigation system works, and the retest that confirms it.How mitigation works
  4. Find a proHire a certified professionalMeasurement and mitigation professionals by state, with their certifications.Find a professional

Informational. Follow EPA guidance. EPA says all radon tests should be taken for a minimum of 48 hours, with windows and doors closed from 12 hours before a short-term test.