RadonZoneReport
No. 222 · Field Edition

The risk
you can't see.

Radon is a colourless, odourless, radioactive gas. The EPA estimates it causes about 21,000 US lung-cancer deaths a year — second only to smoking. We turn your ZIP into a footnoted dossier of what's coming up through the bedrock beneath your floor.

Pull my report · $7 Instant PDF · EPA & AARST sources
EPA Map of Radon Zones · County-level data · AARST mitigation guidelines

What's in the dossier.

A single 6-page PDF, designed to be printed and folded into a folder before your next home inspection or basement remodel. No accounts. No upsell. No newsletter you didn't ask for.

  • EPA Radon Zone (1, 2, or 3) for your county
  • Expected indoor average concentration (pCi/L)
  • How your county compares to neighbouring counties
  • Mitigation cost estimate — AARST-aligned
  • Testing cadence & what to ask your inspector
  • Sources cited, footnoted, dated
01

A real report.

Below: the actual dossier we'd hand you for ZIP 80302 — Boulder County, Colorado.

REPORT · RR-80302

Boulder County, Colorado

ZIP 80302 · Front Range · 5,430 ft elevation
EPA Zone
1
Highest risk
Expected indoor average
4.3 pCi/L
Above the 4.0 EPA action level.
EPA action level
4.0 pCi/L
Mitigation recommended at or above.
Mitigation cost
$1,200–$2,500
Sub-slab depressurization (typical).
Re-test cadence
Every 2 yrs
Or after any basement remodel.

Findings

Boulder County sits on uranium-rich granitic and metamorphic bedrock of the Colorado Front Range. The EPA classifies this county as Zone 1 — the highest of the three risk tiers — meaning the predicted average indoor radon screening level exceeds 4 pCi/L. Colorado state-wide screening averages reported by the Colorado Department of Public Health & Environment sit above the EPA action level, and Boulder County is among the elevated Front Range counties.

Recommended action

If your home has not been tested in the past 24 months, test now using a short-term kit (3–7 days) in the lowest livable level. If results return ≥4.0 pCi/L, commission a quote from a certified mitigator (NRPP or NRSB). Sub-slab depressurisation — the standard intervention — typically runs $800–$2,500 and reduces indoor concentrations by 50–99% per the EPA Consumer's Guide to Radon Reduction.

Sources

  • US EPA — Map of Radon Zones, Colorado (EPA-402-R-93-071)
  • EPA Citizen's Guide to Radon (EPA-402-K-12-002)
  • Colorado Dept. of Public Health & Environment — Radon Program
  • AARST-NRPP — Soil Gas Mitigation Standard SGM-SF-2017
02

What you'll hand to your inspector.

A printed, footnoted, one-look-at-it document with your county's EPA radon zone, expected indoor average, the EPA lifetime lung-cancer risk math, your home's estimated probability of testing above the action level, and the mitigation cost range published for your region.

Designed to land on a contractor's desk, a realtor's table, or a buyer's inspector clipboard without a single sentence of explanation from you.

03

Quality bar.

  • EPA Map of Radon Zones — county-level classification taken straight from EPA-402-R-93-071.
  • Lifetime-risk numbers taken from EPA Table A-1 (EPA-402-R-03-003), not interpolated.
  • Cost ranges from EPA and American Lung Association published guidance, not vendor marketing.
  • Every figure dated. Every claim sourced. No "studies show."
04

How this report is built.

Plain English. Read this before you order.

Primary sources

  • EPA Map of Radon Zones — EPA-402-R-93-071. County-level zone (1/2/3) classifications.
  • EPA Assessment of Risks from Radon in Homes — EPA-402-R-03-003, Table A-1. Lifetime lung-cancer deaths per 1,000 by exposure level.
  • EPA Citizen's Guide to Radon — EPA-402-K-12-002. Action level, testing cadence, mitigation principles.
  • EPA Consumer's Guide to Radon Reduction — EPA-402-K-10-005. Mitigation system types and effectiveness ranges.
  • NRPP & NRSB certification directories — used for "find a mitigator" pointers, not for any vetting claim.
  • State radon programs (CDPHE, Iowa DPH, PA DEP, etc.) — for state-level screening averages.

What's in the number

  • Your zone comes from the EPA county-level map, with a hand-curated set of county overrides where state-published data is more precise than the 1993 national map.
  • Your county average pCi/L is the published state or county screening average — not your home's reading.
  • Your "% likelihood ≥ 4 pCi/L" is a log-normal estimate calibrated against EPA national screening data, adjusted for basement (+8 pts) and home type. It is a population estimate, not a measurement.
  • Mitigation cost uses the EPA / American Lung Association range of $800–$2,500 for sub-slab depressurisation, adjusted modestly by zone.

Honest limits

The EPA Map of Radon Zones was published in 1993 and has not been re-issued; the county classifications are stable but actual home readings vary dramatically house-to-house on the same street. This report is a population-level statistical estimate for the county you specify — it is not a measurement of your home. The only way to know your home's radon level is to test it with a short-term ($15–$30) or long-term ($25–$45) kit. If your county has unusual geology, microclimate, or a recently-published state survey, treat the in-report figures as a starting point, not the last word.

Who builds it

Compiled by an independent research team using federally-published data. Not affiliated with or endorsed by the EPA, AARST, NRPP, NRSB, or any radon-mitigation business. We do not sell tests, mitigation systems, or referrals. We do not collect a commission from anyone you hire. We sell a $7 PDF.

Contact hello@radonzonereport.com Last reviewed June 2026 Refund If we can't generate a report for your county, your purchase is refunded automatically.
05

Pull your report.

Tell us where the house is. The report covers the EPA zone, expected indoor average, your home's estimated probability of testing above the action level, mitigation cost range, and a 14-day testing plan. Delivered as a PDF in under a minute.

County (optional — for finer precision)
Instant PDF · EPA Map of Radon Zones · No account

One ZIP. One PDF. Seven dollars.

Folded, footnoted, in your inbox in under a minute.

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