South Dakota Radon Map, Levels & Testing Guide
Browse the 6 listed county pages surfaced for South Dakota. Open a listed county to compare its EPA zone, source caveats, testing meaning, and when mitigation pricing becomes worth checking.
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Official Evidence in South Dakota
6 of 6 listed counties have official evidence
Open a county page to see the processed verdict: source confidence, local burden, state percentile, and the next step for no reading, 2.0-3.9, or 4.0+ pCi/L.
100%
covered
Measured
6
State source
0
CDC source
6
Needs source detail
0
Measured Risk Leaders in South Dakota
County rankings from actual reported radon tests
These lists rank the visible South Dakota county pages by measured radon signals, not by the EPA zone label alone. Use them to spot where the state hub has a real data story before opening individual county pages.
6
measured counties
State-level verdict
This hub has measured high-burden counties, so the first click should be evidence-led.
The state hub is now doing a decision job: it separates first-click counties, retest counties, and lower-signal counties from 6 visible county measurement rows. 6 counties cross the high measured-burden band, so those pages should answer testing and 4.0+ action questions most directly.
First-click counties
Open Yankton County first when you need the strongest local answer. It is tagged Test-now from 72.9% 4.0+ - 8.6 pCi/L primary - 97 tests. 6 visible measured counties are elevated or high enough to review before lower-signal counties.
Buyer/seller lane
Buyer/seller lane: start with the elevated or high counties, require a fresh lowest-level test, and turn any 4.0+ property result into quote or credit math. The hub has 6 CDC-backed county rows to support that routing.
Retest lane
Retest lane: 2.0-3.9 pCi/L deserves more caution in the elevated/high county set than in lower-signal counties. The hub should send those users to county pages before product or cost paths.
Best county pages to open first
Start with these local evidence pages
Ranked by measured burden, 4.0+ share, test volume, and whether the EPA zone understates the measurement signal.
Yankton County
CDC Tracking
72.9% 4.0+ - 8.6 pCi/L primary - 97 tests
Yankton County is a first-click page: 72.9% of reported tests at or above 4.0 and 8.6 pCi/L primary result. Route no-reading users to a test now and 4.0+ users to quote or credit planning.
Brookings County
CDC Tracking
68.5% 4.0+ - 8.6 pCi/L primary - 276 tests
Brookings County is a first-click page: 68.5% of reported tests at or above 4.0 and 8.6 pCi/L primary result. Route no-reading users to a test now and 4.0+ users to quote or credit planning.
Codington County
CDC Tracking
64.9% 4.0+ - 8.9 pCi/L primary - 58 tests
Codington County is a first-click page: 64.9% of reported tests at or above 4.0 and 8.9 pCi/L primary result. Route no-reading users to a test now and 4.0+ users to quote or credit planning.
Brown County
CDC Tracking
71.0% 4.0+ - 6.6 pCi/L primary - 56 tests
Brown County is a first-click page: 71.0% of reported tests at or above 4.0 and 6.6 pCi/L primary result. Route no-reading users to a test now and 4.0+ users to quote or credit planning.
Highest 4.0+ share
Primary result 8.6 pCi/L - high-end 73.4 pCi/L
CDC Tracking
Primary result 6.6 pCi/L - high-end 18.8 pCi/L
CDC Tracking
Primary result 8.6 pCi/L - high-end 138.9 pCi/L
CDC Tracking
Primary result 8.9 pCi/L - high-end 57.1 pCi/L
CDC Tracking
Primary result 6.5 pCi/L - high-end 204.9 pCi/L
CDC Tracking
Highest high-end reading
4.0+ share 58.5% - primary result 6.5 pCi/L
CDC Tracking
4.0+ share 68.5% - primary result 8.6 pCi/L
CDC Tracking
4.0+ share 72.9% - primary result 8.6 pCi/L
CDC Tracking
4.0+ share 56.5% - primary result 6.5 pCi/L
CDC Tracking
4.0+ share 64.9% - primary result 8.9 pCi/L
CDC Tracking
Most reported tests
4.0+ share 58.5% - primary result 6.5 pCi/L
CDC Tracking
4.0+ share 56.5% - primary result 6.5 pCi/L
CDC Tracking
4.0+ share 68.5% - primary result 8.6 pCi/L
CDC Tracking
4.0+ share 72.9% - primary result 8.6 pCi/L
CDC Tracking
4.0+ share 64.9% - primary result 8.9 pCi/L
CDC Tracking
Measured pattern
Among 6 visible counties with measurement tables, 6 land in the high measured-burden band and 6 land in high or elevated measured-burden bands. That lets this hub rank counties by observed test distribution instead of repeating the EPA map.
Map vs measurements
The strongest measured signals mostly align with the EPA zone structure, so the county pages can use the map as support while still leading with test data.
Source confidence
The measured rows shown here use CDC Tracking. This is still official evidence, but the hub should keep source caveats visible until a stable state table is available.
Already Tested
View South Dakota Cost Estimates
If you already have a radon result, skip the directory and move straight to local price guidance.
Understand the Number
2.0 vs 4.0 vs 8.0 pCi/L
Use the parent levels guide if you need the plain-English meaning of a radon result before browsing counties.
Need a Number First
Read the Testing Guide
Use the fastest valid radon test setup before you compare quotes or ask whether mitigation is worth it.
Browse Counties
Jump to the Directory
Open your county to see its EPA zone, testing meaning, and the point where mitigation becomes worth pricing.
Official State Resource
South Dakota radon program and rules
Use the state program link to verify local radon guidance, disclosure language, and contractor credential expectations before you act on an estimate.
Disclosure rule tracked
South Dakota requires sellers to disclose known property conditions through a Property Condition Disclosure Statement.
Credential note
South Dakota does not require specific radon licensing.
Already tested? Get your itemized mitigation cost estimate.
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