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Radon in Petroleum County, Montana

Petroleum County, Montana, is in EPA radon Zone 2: predicted average indoor radon screening level from 2 to 4 pCi/L (moderate potential). No laboratory test results are on file for this county (no tests reported, or too few to publish).

Zone 2
EPA radon zone (1993 county map)
n/a
median lab test, pCi/L (2008-2017)
n/a
of lab tests at or above 4 pCi/L
n/a
buildings tested by labs, 2008-2017

Radon test results in Petroleum County

No radon test results are on file for Petroleum County. Its EPA zone is Zone 2.

Test results describe buildings whose owners chose to test and whose results reached the lab or agency, not a random sample; small counts swing widely. State and US shares are computed from county counts and percents. The laboratory data comes from national radon testing laboratories and supplements EPA's zone map.

Radon in nearby counties

CountyEPA zoneLab tests4 pCi/L or more
Musselshell County, MTZone 21429.4%
Fergus County, MTZone 15772.4%
Garfield County, MTZone 1n/an/a
Golden Valley County, MTZone 2n/an/a
Treasure County, MTZone 21100%
Phillips County, MTZone 1n/an/a

The six counties with the nearest centers.

What to do about radon in Petroleum County

Test the building. EPA recommends fixing a home at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, and says there is no known safe level of exposure. Montana's state radon program can point you to testers and test kits.

Buying here? The Environmental Records Report lists this county's radon zone and test results with the flood zone, mapped faults, power lines and federal contamination records near the address.

Check one Petroleum County address

Environmental Records Report, $29. PDF and JSON, usually ready in about a minute.

Radon in Petroleum County: questions

What is the radon level in Petroleum County?

No laboratory results are on file for Petroleum County. The county's EPA zone is Zone 2. Only a test of the building gives its level.

Is Petroleum County in radon Zone 1?

No. EPA's 1993 map puts Petroleum County in Zone 2 (predicted average indoor radon screening level from 2 to 4 pCi/L (moderate potential)). EPA says homes in every zone can have high radon and should be tested.

Should I test for radon in Petroleum County?

Yes. EPA recommends testing every home whatever its zone: "This map should not be used to determine if individual homes need to be tested." Fix the home at 4 pCi/L or more and consider a fix between 2 and 4 pCi/L; EPA says there is no known safe level of radon exposure.

More for Petroleum County

Other free hazard lookups

All of these, plus wetlands, FEMA hazard ratings and the federal contamination lists, are in the Environmental Records Report for any US address ($29).

Radon in every Montana county · Radon map of every state

Data compiled 2026-10-20. County FIPS 30069. County-level screening information, not a radon measurement of any building.