EPA predicted potential
Zone 2 indicates predicted average indoor screening levels of 2–4 pCi/L. It cannot predict a specific home.
The bottom line
Treat the county number as context, not clearance.
A countywide average cannot clear a particular address. Chester County’s public dashboard values were stable across two checks, but the hidden test count makes the result fragile. The useful next fact is a measurement from the house itself.
Dashboard maximum, pCi/L
Average and median were both 1.0 pCi/L. All three values matched on two checks; test count was not displayed.
Certified pros based in-county
No NRPP- or NRSB-listed professional was found based in Chester County when checked October 16, 2026.
Risk profile
Zone 2, with a narrow local snapshot.
The EPA designation and the state dashboard answer different questions. One estimates county potential; the other reports a limited two-year set of submitted tests.
Chester County is EPA Radon Zone 2.
Zone 2 denotes predicted average indoor screening levels of 2–4 pCi/L. It is a planning classification, not a pass/fail result for any address.
EPA Map of Radon Zones: Tennessee · EPA Map of Radon Zones: Tennessee · EPA definitions ↗
1.0Average pCi/L
1.0Median pCi/L
1.2Maximum pCi/L
The Chester County tooltip produced these same values on two separate loads on October 16, 2026, with Year set to “(All)” for 2022–2023. The dashboard does not show the number of tests, so do not infer sample size from the values.
The lower band charts are regional, not county-level.
Selecting Chester County did not change the pre- and post-mitigation charts from health-region aggregates. Those bars cannot be used to publish a Chester County test count or percentage above any band.
Building codes
The city answer is clear. The county answer is not.
Henderson and unincorporated Chester County both operate local enforcement programs, but only the city’s appendix list was found.
2018 IRC; no Appendix F
- Ordinance #517, August 2018, adopted the 2018 International Residential Code.
- The ordinance names Appendices B, C, G, and N only.
- Appendix F—the 2018 IRC radon appendix—is not adopted, so radon-resistant construction is optional in Henderson.
2018 IRC adopted in 2021
- Countywide residential permits have been required since 2017.
- The county says its requirements were updated in 2021 to adopt the 2018 IRC.
- The adopting resolution and appendix list were not found, so Appendix F status is unverified.
Local enforcement
The State Fire Marshal program is not the controlling local program.
Chester County’s Building & Zoning page says the county and City of Henderson manage local residential permits, with the two systems “practically mirror[ing] one another.” The county’s own program means unincorporated areas do not rely on the state’s fallback residential permit program.
Codification limitNeeds current confirmation
Henderson’s available code runs through August 12, 2021.
No later 2021 or 2024 IRC update was found, but a later ordinance would not appear in the MTAS volume reviewed. Confirm the current edition before a permitting decision.
Other local rules
No county- or city-specific radon rule was found.
The search found no Chester County or Henderson radon rule for schools, public buildings, or real-estate transactions. Tennessee encourages school testing rather than requiring it; a proposal to mandate school radon testing did not become law. This is an absence-of-evidence finding, not proof that no unpublished policy exists.
50-state school-radon review ↗ · HB1269 proposal ↗ · HJR0696 language ↗
For homebuyers
Put the test inside the inspection window.
No Chester County-specific point-of-sale radon rule was found. Tennessee’s statewide disclosure form asks about known radon and advises buyers to use a radon inspection contingency.
Make radon a written inspection contingency.
The statewide Residential Property Condition Disclosure advises buyers to include a radon inspection contingency. A disclosure of known conditions is not the same thing as a current test.
Test even when the dashboard numbers look low.
The 1.0 pCi/L average and median describe an undisclosed number of 2022–2023 tests, not your address. The sample may be small.
Ask new-home builders what was installed.
Henderson does not require the radon appendix; the unincorporated county’s appendix status is unverified. Ask directly whether radon-resistant features were included.
Use the state’s free-kit program.
The Tennessee Department of Environment and Conservation offers free radon test kits to homeowners. Availability and program details should be checked on the program page.
Tennessee residential disclosure form ↗ · TDEC radon program ↗
Housing context
A modest-growth market with active small-scale building.
Recent index snapshots point to steady rather than explosive growth. That makes both resale testing and builder questions relevant.
01,147
Estimated 2026 population
World Population Review estimated Chester County at about 18,147 residents.
Index result, updated around September 2026.
+0.85%
Estimated annual growth
The same index described growth at roughly 0.85% per year, compared with a 2020 census count of about 17,379.
4
New-home communities
A NewHomeSource index listed four Henderson communities, about 19–22 new homes, and two builders.
$235K–$390K
Listed new-home range
The same index showed this range for active small-scale new construction around Henderson.
How do I find a certified radon professional in Chester 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.
Answers in brief
Chester County radon FAQ
Is Chester County in a high-radon area?
Chester County is in EPA Zone 2, which indicates moderate predicted potential and average indoor screening levels of 2–4 pCi/L. The zone cannot predict a particular home’s result; testing is the only way to know.
What did the Tennessee dashboard show?
On two checks on October 16, 2026, the Chester County tooltip showed a 1.0 pCi/L average, 1.0 median, and 1.2 maximum for the 2022–2023 dataset. The number of tests was not displayed, so the result should be treated as a limited local snapshot.
Does Henderson require radon-resistant new construction?
No. Henderson’s 2018 IRC adoption names Appendices B, C, G, and N only. Appendix F, the radon appendix, is not adopted, so radon-resistant features are optional.
What about unincorporated Chester County?
The county says it adopted the 2018 IRC in 2021 and operates its own permit program, but the appendix list was not found. Whether Appendix F is adopted remains unverified.
Is radon testing required when a home is sold?
No Chester County-specific testing mandate was found. Tennessee’s disclosure form asks sellers about known radon gas, advises buyers to include a radon inspection contingency, and does not require sellers to test.
Are local certified testers available?
None were found based in Chester County or nearby Jackson/Madison County in NRPP and NRSB directory checks on October 16, 2026. The nearest NRPP listings were roughly 66–70 miles away.
Research trail
Primary and supporting sources
Dashboard and professional-directory observations were checked October 16, 2026. Code dates and source limits are noted in the text.
- Henderson Municipal Code, Title 12 — 2018 IRC adoption and appendix list; MTAS codification through August 12, 2021.
- Henderson Title 12 extract — supporting ordinance history.
- Chester County Building & Zoning — permits since 2017 and 2018 IRC update in 2021.
- Tennessee State Fire Marshal residential permits — state program scope and baseline codes.
- Tennessee Radon Testing dashboard — two verified Chester County tooltip observations.
- EPA Map of Radon Zones — zone definitions and limitations.
- EPA Map of Radon Zones: Tennessee and EPA Map of Radon Zones: Tennessee — supporting Chester County Zone 2 designation.
- NRPP Find a Professional — ZIP 38340 and 38301 observations.
- NRSB Find a Professional — Tennessee-constrained 50- and 100-mile searches.
- Tennessee Residential Property Condition Disclosure, RF 201 — version 01/01/2025.
- 50-state school radon law review · HB1269 · HJR0696.
- World Population Review: Chester County — 2026 estimate and growth index.
- NewHomeSource: Henderson area — new-construction index.
- Tennessee Department of Environment and Conservation radon program — free homeowner test-kit program.