EPA Zone 2 · moderate
2Broad county designation, confirmed by two zone-reference sources reviewed October 15, 2026.
01 / RISK SIGNAL
One county, one unresolved dashboard anomaly
The Zone 2 designation describes broad potential. The dashboard’s 2022–2023 tooltip displays three values that cannot all describe one ordinary dataset, so no reliable county average can be inferred from it.
SOURCE · TN RADON TESTING DASHBOARD6.5
pCi/L · average
EPA action level: 4.0 pCi/L.
The dashboard labels 6.5 as an average, but its own median and maximum make that result unusable without clarification.
1.6
Median · pCi/L
8.9
Maximum · pCi/L
Read carefully. The dashboard displayed all three values under its own “County: White” label, but the trio is mathematically inconsistent if it describes one ordinary dataset: an average of 6.5 cannot coexist with a median of 1.6 and maximum of 8.9. Treat this as an unresolved dashboard anomaly, not a clean county statistic. The workbook gives no county sample size or CSV export, and its pre/post charts are health-region aggregates—not White County counts.
02 / CODE SPLIT
Radon-ready in Sparta. Likely optional beyond it.
Sparta’s published ordinance is clear: Appendix F is adopted. White County’s September 2022 resolution is not readable online, so the unincorporated conclusion remains a strong inference—not a verified appendix list.
SOURCES · SPARTA TITLE 12 + TENNESSEE RULE 0780-02-23-.02City of Sparta
Published code: 2018 IRC
APPENDIX LISTA, B, C, D, E, F, G, H, I, J, K, M, N, P
ADOPTING HISTORY#13-873 → #17-908 → #22-943; the January 2022 action amended the appendix list.
PRACTICAL EFFECTRadon-resistant construction is part of the adopted code, but active enforcement in a Zone 2 county is not confirmed.
The MTAS codification is current only through April 2022. No later code update was found online.
Unincorporated White County
Reported code: 2018 IRC, adopted September 2022
WHAT IS KNOWNThe county inspector said White County would use the same residential codes as the state when local inspections began February 1, 2023.
STATE BASELINETennessee’s rule adopts the 2018 IRC with Appendix Q only—not Appendix F.
BEST-SUPPORTED READINGRadon-resistant construction is almost certainly optional, but the county resolution must be checked before treating that as final.
The scanned adoption resolution has no extractable text. No ordinance or resolution number is published here because none was verified.
Town of Doyle
County performs building inspections
LOCAL ENFORCEMENTAn MTAS municipal-services survey records: “County does building inspections.”
LOCAL CODEDoyle’s published municipal code is dated and does not establish a current radon appendix.
PRACTICAL EFFECTThe same likely-optional conclusion as unincorporated White County applies.
For White County’s 2018 IRC, the radon appendix is Appendix F. Newer labels AF (2021) and BE (2024) do not apply here.
How do I find a certified radon professional in White County?
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.
03 / REAL ESTATE
Growth meets a young inspection regime
White County’s own residential inspection program began in 2023. That makes location, construction date, builder documentation and an actual radon test more useful than assumptions about “new construction.”
+8.3%
Population growth from 27,351 in 2020 to a July 1, 2025 estimate of 29,612. Source: U.S. Census Bureau QuickFacts.
163
Residential building permits reported for 2025. Source: U.S. Census Bureau QuickFacts.
2023
County residential inspections began February 1. The program covers residential construction; commercial standards were still being proposed in October 2026.
Five questions for a buyer
- Confirm the jurisdiction. Sparta and unincorporated White County do not have the same radon-code posture.
- Ask for the radon rough-in details. In Sparta, request documentation of Appendix F features rather than assuming they were installed.
- Test every home. The dashboard displays an average above the action level, but its three county metrics are internally inconsistent; an actual home test is more useful than this aggregate display.
- Use the inspection period. Tennessee’s property-condition disclosure explicitly names radon gas; known conditions must be disclosed, subject to statutory exemptions.
- Plan ahead for a pro. The nearest NRPP measurement listing was more than 50 miles from Sparta in the October 15 directory snapshot.
04 / PRACTICAL HELP
Radon testing resources
A home test is the only way to know your radon level. These public resources can help with a free kit, live questions, certified professionals, and next steps after a high result.
Test your home
- Free test kit from TDEC — Tennessee’s radon program
- Buy a kit by phone: 1-800-SOS-RADON (1-800-767-7236)
- Live help with your questions: 1-800-55RADON (1-800-557-2366)
- Find a certified pro: NRPP 800-269-4174 · NRSB 866-329-3474
If your result comes back high
- 1-800-644-6999 — the Fix-It Hotline, for general guidance on lowering radon in your home
05 / SOURCES
Evidence trail
Values and directory results are dated snapshots. Code conclusions distinguish published ordinance text from inferences and unresolved items.
Sparta Municipal Code · Title 12
2018 IRC adoption and §12-402 appendix list; MTAS copy current through April 2022. Open PDF ↗
ICC · 2018 IRC Appendix F
Radon Control Methods; appendix is mandatory only when referenced by the adopting ordinance. Open source ↗
Tennessee Rule 0780-02-23-.02
State residential baseline: 2018 IRC and Appendix Q. Revised February 2024. Open PDF ↗
Tennessee Radon Testing dashboard
2022–2023 tooltip values displayed for County: White, label-checked live October 15, 2026; the average/median/maximum trio is internally inconsistent and flagged on this page. Open dashboard ↗
NRPP professional directory
Measurement-professional searches for Sparta 38583 and Cookeville 38501; verified live October 15, 2026. Open directory ↗
NRSB professional directory
RMS and RMT searches for Sparta and Cookeville within 50 miles; verified live October 15, 2026. Open directory ↗
White County government
Building Inspector page and scanned adoption resolution; director and office number observed October 15, 2026. Open county site ↗
U.S. Census Bureau QuickFacts
White County population estimates and 2025 residential building permits; source reviewed October 15, 2026. No exact public URL was carried into this research record.
Tennessee property disclosure
TAR Form F16, item C.1, and TCA §66-5-209 exemptions; sources reviewed October 15, 2026. No exact public URL was carried into this research record.
Upper Cumberland reporting
County code adoption, February 2023 inspection takeover, permit-office growth and October 2026 commercial-code proposal; source pages reviewed October 15, 2026.
Research note: The dashboard’s county tooltip does not state whether average, median and maximum combine pre- and post-mitigation tests. Directory listings are self-reported and may omit working testers. “No local rule found” reflects searches of published codes, agendas and state/municipal resources—not a legal opinion.