Sumner County Radon · County research brief · October 2026
A moderate-risk county with no radon-resistant construction mandate confirmed in any jurisdiction reviewed. Four appendix decisions are clear; four still need direct verification.
Research reviewed October 15, 2026 · Building-code status is jurisdiction-specific
EPA zone: Zone 2Region: Middle TennesseeState test data: State test figures confirmed on repeat checks
It can be. Sumner County is in EPA Zone 2, where the predicted average indoor screening level is 2 to 4 pCi/L. Homes above EPA's 4 pCi/L action level are found in every zone, so a test is the only way to know your home's level.
No, not in Hendersonville, Gallatin, White House or unincorporated Sumner County: all omit or exclude the radon appendix. Portland, Millersville, Westmoreland and Mitchellville weren't confirmed. Local code details
Order a free short-term kit from the Tennessee Radon Program online or by calling 1-800-232-1139. Place it on the lowest lived-in floor, about 3 feet off the floor, for 3 to 5 days, then mail it back right away. How to test your home
EPA recommends fixing your home if radon is 4 pCi/L or higher, and considering a fix between 2 and 4 pCi/L. Confirm a high short-term result with a second test first. What your result means
Tennessee doesn't license radon professionals, so look for NRPP or NRSB certification. Search both national directories by ZIP code; certified professionals often serve Sumner County from nearby cities. How to choose a radon professional
The clearest local story remains the gap between growth and code: Gallatin and Hendersonville are expanding, yet the radon appendix is not part of the verified residential code packages.
Hendersonville, Gallatin, White House, and unincorporated Sumner County all omit or exclude the IRC radon appendix. The other four jurisdictions remain unverified.
Sources: municipal code records and county Resolution No. 1506-02.
Portland, Millersville, Westmoreland, and Mitchellville need an appendix-level confirmation before any countywide claim can be absolute.
Status as of the October 15, 2026 research review.
The unfiltered directory surfaced one Gallatin-based dual-service listing; the measurement-filtered search surfaced none in-county.
NRPP directory, read October 15, 2026.
Verified Sumner County dashboard readings: Average 2.4 pCi/L, median 1.4 pCi/L, and maximum 9.3 pCi/L for the dashboard’s 2022–2023 tests. The tooltip was rechecked October 14, 2026 with the “County: Sumner” label confirmed. The pre/post band charts show health-region aggregates—not county-specific counts or percentages—so those figures remain unsuitable for Sumner County.
Use the filter to separate confirmed appendix decisions from open questions. “No” means the researched adoption language omits or excludes the radon appendix; “open” means the current appendix list was not verified.
Municipal Code §12-202 lists adopted appendices A, B, G, H, J, N, O, and P. The code search returned no radon provision, and Appendix AF—the 2021 radon appendix—is not in the adopted list, so radon-resistant new construction is optional.
Source: City policies and adopted codes; Municode §12-202. Ordinance history cites 2025-04.
Municipal Code §5-56 adopts the 2024 IRC “excluding appendices.” That excludes Appendix BE, the 2024 radon-control appendix.
Source: City adopted ordinances and amendments; Ord. O2407-36.
The researched MTAS code copy lists Appendix G only. Appendix F is not adopted. White House spans Sumner and Robertson counties.
Source: MTAS-hosted White House Title 12, §12-501 (index source; October 2023 amendment).
The last documented adoption states: “No appendices … are adopted except: Appendix M.” Appendix F is not adopted. A current-edition confirmation is still prudent.
Source: County commission minutes, adopted 9/21/2015.
The current code edition was verified, but no published appendix list was found. The 2020 adopting ordinance or residential-code section would settle Appendix F.
Source: City ICC code reference. Confirmation contact in the research record: 615-325-6776.
The edition and effective date are published. The August 16, 2022 amendments file could not be text-extracted, so Appendix AF—the 2021 radon appendix—remains unresolved. Millersville spans Sumner and Robertson counties.
Source: Construction Services; city document record.
The online MTAS copy is visibly outdated and contains no residential-code chapter. Current code and Appendix F adoption require direct confirmation.
Source: outdated MTAS Title 12 copy; Building and Codes contact in the research record: 615-644-2640 ext. 106.
No municipal building code was found online. State Fire Marshal enforcement of the 2018 IRC is plausible, but that is an inference—not a verified local finding.
Source: MTAS code-adoption guidance; confirm with the town or State Fire Marshal.
A new home is not automatically a radon-resistant home. Tennessee’s seller form also allows “UNKNOWN” on the general environmental-hazards question when the seller has no knowledge.
EPA Zone 2 describes predicted countywide potential. It does not determine an individual address, floor plan, foundation, or result.
Sources: Tennessee Association of Realtors RF 201 (version 01/01/2025); TDEC Radon Program.
Practical ways to test, get a result explained, and find qualified help if a reading comes back high.
Hotline information: U.S. EPA and CDC.
1-800-644-6999 — the Fix-It Hotline, for general guidance on lowering radon in your home.
Hotline information: U.S. EPA and CDC.
The American Lung Association offers a free Radon Basics course for a fuller introduction to testing, health risk, and next steps.
Health statistics and testing cadence: American Lung Association. Action-level guidance: U.S. EPA.
Tennessee doesn't license radon testers or mitigators, so national certification is the best way to check qualifications. The Tennessee Radon Program points residents to two directories: search them by ZIP code and widen the radius if nothing is listed nearby.
We don't recommend or rank companies. Before you hire, check the certification number in the directory yourself and ask for a follow-up test after any system is installed. Questions to ask a radon professional.
The research sweep found no Sumner County or city-specific rule for public buildings, schools, or real-estate transactions beyond state norms. This is a “not found” result, not proof that no unpublished policy exists.
Nearby historical contrast: Metro Nashville’s 1989 Board of Health Regulation No. 9 required radon surveys in public buildings at least every five years and reduction plans above 4 pCi/L. The rule text remains published, but its current enforcement status is unverified. Tennessee school testing is encouraged rather than required.
Primary municipal and county records lead; index-only and directory sources are labeled in the page.
Method: web-source review completed October 15, 2026. “Verified” in this brief means the cited adoption language or current city code was observed in the research record. Directory results are snapshots and may change. EPA zones describe predicted county potential, not individual buildings.