Radon Mitigation in Shrewsbury Township, PA
Updated
PA DEP has 4,527 home radon tests on record from the ZIP codes that cover Shrewsbury Township (17349, 17327). 55.5% came back at or above the EPA's 4.0 pCi/L action level, against 52.5% for York County as a whole. That is close to the county-wide rate, which is itself about one test in two. A standard system here typically costs $800 to $1,500. The only way to know about one house is to test it.
Shrewsbury Township sits along Interstate 83 at the Maryland line and surrounds the boroughs of Shrewsbury, Glen Rock, Railroad and New Freedom. It is mostly single-family homes (83% detached). It overlaps ZIP 17349 (New Freedom), where 52% of tests came in at or above the action level, and 17327 (Glen Rock), where 61% did.
What the PA DEP test records show for Shrewsbury Township
ZIP codes don't follow township lines, so the 2 ZIP codes below also take in some homes just outside Shrewsbury Township.
| ZIP | Tests | Median pCi/L | 4+ pCi/L | 10+ | 20+ |
|---|---|---|---|---|---|
| 17349 | 2,730 | 4.3 | 52% | 25.5% | 11.2% |
| 17327 | 1,797 | 5.9 | 60.8% | 35.6% | 20.6% |
| York County | 98,845 | 4.3 | 52.5% | 26.8% | 13.1% |
- ZIP 17349 (about 50% of Shrewsbury Township's land): median 4.3 pCi/L across 2,730 tests, 11.2% at 20 or higher, top reading 240. Basement median 4.7, first floor 2.8.
- ZIP 17327 (about 41% of Shrewsbury Township's land): median 5.9 pCi/L across 1,797 tests, 20.6% at 20 or higher, top reading 397. Basement median 6.4, first floor 3.2.
The spread inside Shrewsbury Township runs from 52% of tests high in 17349 to 60.8% in 17327.
Half of the story is the median. The other half is the tail: 29.5% of tests here were 10 pCi/L or higher and 14.9% were 20 or higher. The top reading on record in these ZIP codes is 397 pCi/L. Neighboring houses can differ by a factor of ten, so none of this tells you what your house is. It tells you the odds are high enough that a $15 to $30 test kit is worth buying.
Tests people chose to run, not a random survey. Details on the York County radon levels page.
Basement readings versus first-floor readings
In ZIP 17349, basement tests have a median of 4.7 pCi/L, while tests taken on the first floor have a median of 2.8 pCi/L (235 first-floor tests). The gap is smaller than in most of the county, which means readings upstairs here are not much of a relief from the basement number.
Radon results by decade in ZIP 17349
| Decade tested | Tests | Median pCi/L | 4+ pCi/L |
|---|---|---|---|
| 1990s | 330 | 5.4 | 60% |
| 2000s | 677 | 5 | 57.2% |
| 2010s | 1,076 | 4.6 | 55.1% |
| 2020s | 614 | 2.3 | 36% |
The share peaked in the 1990s at 60% and sits at 36% for tests since 2020. A drop that size is mostly about who is testing, not the ground. More recent tests come from home sales and from retests after a system went in, and both pull the share down. The rock under Shrewsbury Township has not changed. 614 tests have been logged in 17349 since 2020, so people here are still testing.
The ground under Shrewsbury Township
Shrewsbury is in the Piedmont Upland of southern York County. Schist and related metamorphic rock, including units mapped as Peters Creek Schist in this part of the county, underlie most of it.
The Glen Rock side tests higher. In 17327, the median is 5.9 pCi/L and 21% of tests reached 20 pCi/L or more.
Housing in Shrewsbury Township and what it means for a system
Census Bureau, American Community Survey 2020 to 2024:
| Shrewsbury Township | York County | |
|---|---|---|
| Homes (housing units) | 2,802 | 189,857 |
| Median year built | 1983 | 1976 |
| Built before 1940 | 6.7% | 18.3% |
| Built before 1980 | 44.8% | 54.8% |
| Built 2000 or later | 23.8% | 20.6% |
| Single-family detached | 82.9% | 64.3% |
| Attached (rowhome, townhouse) | 8% | 17.1% |
| Mobile homes | 4.2% | 4.1% |
| Owner-occupied | 86.2% | 76.3% |
82.9% of homes in Shrewsbury Township are single-family detached. A detached house with a basement is the easiest layout to mitigate: one suction point through the slab, a fan outside or in the garage, and a vent above the roof line. It is the standard sub-slab depressurization job covered step by step on our mitigation process page, and it usually lands in the middle of the cost range.
Cost-wise, most houses in Shrewsbury Township are the standard $800 to $1,500 sub-slab job, with block walls or a second suction point pushing toward $2,500. Full ranges on the cost page.
Where we work in Shrewsbury Township
That covers the areas around Shrewsbury, Glen Rock, Railroad and New Freedom boroughs. Interstate 83 and Route 851 cross the township. Public schools here are part of the Southern York County School District. The township dates to 1742, and several bridges from the Northern Central and Stewartstown railways are on the National Register.
Installers must hold a PA DEP radon mitigation certification (how to check).
Common questions
Is radon a problem in Shrewsbury Township?
Yes. PA DEP has 4,527 tests on record from the ZIP codes covering Shrewsbury Township, and 55.5% of them came back at or above the EPA's 4.0 pCi/L action level. 14.9% were at 20 pCi/L or more. The county-wide rate is 52.5%.
What is the average radon level in ZIP 17349?
The median of 2,730 PA DEP tests in ZIP 17349 is 4.3 pCi/L and the mean is 9.3 pCi/L. A mean that far above the median means a long tail of very high readings, topping out at 240 pCi/L.
Nearby
Hopewell Township 58%, York Township 57%. Share of PA DEP tests at or above 4.0 pCi/L, against 55.5% here.
Have a test result from Shrewsbury Township?
Send us the number and the foundation type, or call and read it out.
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