Radon levels in Rockingham County, New Hampshire

ModerateEPA Zone 2

Predicted long-term basement average of 2.2 pCi/L (model estimate) across 36 ZIP codes - about 1.2× the US average of 1.8, close to the New Hampshire average of 2.1. Ranked #2 of 10 New Hampshire counties.

Test Rockingham County, NH - the EPA says "consider fixing" in this range

The predicted basement average here is 2.2 pCi/L, in the 2-4 pCi/L band where the EPA recommends considering mitigation. Plenty of individual homes in a moderate area test above 4. Start with a short-term test; if it comes back at 2 or higher, follow up with a long-term test or a continuous monitor.

Already tested at 4 pCi/L or higher? Find a certified mitigation professional (EPA). A mitigation system typically runs $800-$2,500 installed.

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Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. How the numbers work.

2.2 ± 0.07

pCi/L predicted basement mean (model SD)

1.3 ± 0.06

pCi/L predicted upstairs (above-ground) mean

1.6-4.2

range of ZIP-level basement predictions in the county

What this means for Rockingham

The typical Rockingham County home is predicted in the 2-4 pCi/L band. The EPA's guidance for this range is to consider fixing, because there is no known safe level and roughly one home in several in a moderate area will test above 4.

The 1993 EPA zone (2) and the 2001-2021 model agree for Rockingham. County figures weight each ZIP by its 2010 Census population, so they describe where people live rather than empty land.

Comparable New Hampshire counties: Strafford County (2.2), Carroll County (2.3), Coos County (2.1), Hillsborough County (2.1). The state's highest is Carroll County at 2.3 pCi/L.

ZIP codes in Rockingham County

Predicted basement and upstairs means by ZIP (model estimate). ZIPs whose land is mostly in this county.

ZIPBasementUpstairsGrade
030382.2 ± 0.091.3Moderate
030791.9 ± 0.091.1Low
030532.4 ± 0.071.6Moderate
038011.7 ± 0.051.0Low
038331.6 ± 0.091.1Low
038422.0 ± 0.091.0Low
030872.5 ± 0.081.8Moderate
030773.2 ± 0.071.4Moderate
038571.9 ± 0.051.1Low
038741.8 ± 0.051.0Low
038651.9 ± 0.111.4Low
038852.2 ± 0.051.4Moderate
038112.6 ± 0.081.2Moderate
030422.4 ± 0.071.2Moderate
038412.5 ± 0.051.5Moderate
038483.5 ± 0.061.4Moderate
038732.4 ± 0.041.3Moderate
038702.0 ± 0.051.3Moderate
030322.6 ± 0.051.8Moderate
030362.4 ± 0.061.4Moderate
032902.8 ± 0.052.0Moderate
038582.3 ± 0.051.3Moderate
038192.5 ± 0.061.3Moderate
038622.9 ± 0.071.3Moderate
030442.5 ± 0.051.5Moderate
032612.8 ± 0.051.7Moderate
030372.8 ± 0.051.8Moderate
030344.2 ± 0.072.1High
038402.4 ± 0.051.4Moderate
038272.1 ± 0.051.1Moderate
038262.2 ± 0.051.4Moderate
038442.3 ± 0.051.2Moderate
038562.2 ± 0.051.3Moderate
038542.2 ± 0.071.5Moderate
038711.7 ± 0.070.9Low
032912.3 ± 0.061.3Moderate

If your test comes back at 4 pCi/L or higher

Mitigation is a routine job: a fan-driven pipe that vents soil gas from under the slab to above the roofline, typically $800-$2,500 installed (typical range; local quotes vary). Use certified professionals: EPA find-a-professional. Read the full mitigation guide.

Rockingham County radon questions

Is radon high in Rockingham County, New Hampshire?
Moderate. The model predicts a long-term basement average of 2.2 pCi/L in Rockingham County (about 1.2× the US average of 1.8 and close to the New Hampshire average of 2.1). That is in the 2-4 pCi/L range where the EPA recommends considering mitigation. Ranked 2 of 10 New Hampshire counties.
Should I test for radon in Rockingham County?
Yes, soon. With a predicted average of 2.2 pCi/L and at least one ZIP predicted at 4.2, many homes in Rockingham County will test above the 4 pCi/L action level. Use a short-term kit first; if it reads 2 or higher, confirm with a long-term test or continuous monitor before deciding on mitigation.
What does EPA Radon Zone 2 mean for Rockingham County?
Zone 2 - moderate potential (2-4 pCi/L). The zone map dates from 1993 and classifies whole counties. The 2001-2021 model agrees with the zone here. Neither replaces a test of your own home.
How much does radon mitigation cost in Rockingham County?
A standard active sub-slab depressurization system typically runs $800-$2,500 installed nationally; New Hampshire quotes vary with foundation type (slab, crawlspace, basement), home size and local labor. Get two or three bids from certified mitigators listed by your state radon program or the EPA's find-a-professional page.

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