Radon Mitigation in North Codorus Township, PA
Updated
PA DEP has 8,426 home radon tests on record from the ZIP codes that cover North Codorus Township (17362, 17360, 17408). 55.6% came back at or above the EPA's 4.0 pCi/L action level, against 52.5% for York County as a whole. Roughly in line with York County overall, where about half of all tests come back high. A standard system here typically costs $800 to $1,500. The only way to know about one house is to test it.
North Codorus Township covers the country around Spring Grove and surrounds New Salem, southwest of York. It overlaps three ZIP codes, and two of them test high: 17362 (Spring Grove) has a median of 5.8 pCi/L, and 17360 (Seven Valleys) has 7.5 pCi/L with 63% of tests at or above the action level. In 17362, 23% of tests reached 20 pCi/L or more, one of the highest shares in the county.
What the PA DEP test records show for North Codorus Township
ZIP codes don't follow township lines, so the 3 ZIP codes below also take in some homes just outside North Codorus Township.
| ZIP | Tests | Median pCi/L | 4+ pCi/L | 10+ | 20+ |
|---|---|---|---|---|---|
| 17362 | 3,003 | 5.8 | 58.6% | 38% | 22.9% |
| 17360 | 1,543 | 7.5 | 63.4% | 41.6% | 24.7% |
| 17408 | 3,880 | 4 | 50.1% | 23.4% | 10.7% |
| York County | 98,845 | 4.3 | 52.5% | 26.8% | 13.1% |
- ZIP 17362 (about 58% of North Codorus Township's land): median 5.8 pCi/L across 3,003 tests, 22.9% at 20 or higher, top reading 673. Basement median 7.2, first floor 2.8.
- ZIP 17360 (about 24% of North Codorus Township's land): median 7.5 pCi/L across 1,543 tests, 24.7% at 20 or higher, top reading 318. Basement median 8, first floor 4.6.
- ZIP 17408 (about 18% of North Codorus Township's land): median 4 pCi/L across 3,880 tests, 10.7% at 20 or higher, top reading 203. Basement median 4.8, first floor 1.4.
The spread inside North Codorus Township runs from 50.1% of tests high in 17408 to 63.4% in 17360.
Half of the story is the median. The other half is the tail: 31.9% of tests here were 10 pCi/L or higher and 17.6% were 20 or higher. The top reading on record in these ZIP codes is 673 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 17362, basement tests have a median of 7.2 pCi/L, while tests taken on the first floor have a median of 2.8 pCi/L (276 first-floor tests). The basement number runs 2.6 times the first-floor number, which is the usual pattern: radon comes up from the soil, so it is strongest at the lowest level and gets diluted as it moves up through the house.
It also explains why two neighbors can get very different results. One tested a finished basement, the other tested a first-floor bedroom. For a decision about mitigation, the test that counts is the one from the lowest level anyone spends time in.
Radon results by decade in ZIP 17362
| Decade tested | Tests | Median pCi/L | 4+ pCi/L |
|---|---|---|---|
| 1990s | 160 | 5 | 55.6% |
| 2000s | 1,007 | 5.2 | 56.2% |
| 2010s | 1,240 | 6.5 | 62.2% |
| 2020s | 578 | 5.2 | 56.1% |
The share peaked in the 2010s at 62.2% and sits at 56.1% for tests since 2020. That is a small move, well within what you'd expect from a shifting mix of home-sale tests and retests. 578 tests have been logged in 17362 since 2020, so people here are still testing.
The ground under North Codorus Township
North Codorus sits southwest of York, where the York Valley lowland meets the Piedmont Upland.
ZIP 17362's mean reading is 17.5 pCi/L, far above its 5.8 median. When a mean runs that far above the median, it means a lot of very high readings. Here, one test in ten came in above 44 pCi/L.
Housing in North Codorus Township and what it means for a system
Census Bureau, American Community Survey 2020 to 2024:
| North Codorus Township | York County | |
|---|---|---|
| Homes (housing units) | 4,036 | 189,857 |
| Median year built | 1982 | 1976 |
| Built before 1940 | 11.3% | 18.3% |
| Built before 1980 | 46.7% | 54.8% |
| Built 2000 or later | 24.6% | 20.6% |
| Single-family detached | 81.4% | 64.3% |
| Attached (rowhome, townhouse) | 5.3% | 17.1% |
| Mobile homes | 3.8% | 4.1% |
| Owner-occupied | 83.7% | 76.3% |
81.4% of homes in North Codorus 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 North Codorus 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 North Codorus Township
That covers the area around New Salem and the countryside around Spring Grove. Routes 116 and 214 run through the township. Public schools here are part of the Spring Grove Area School District. Hanover Junction station and the Howard Tunnel on the old Northern Central Railway are both on the National Register.
Installers must hold a PA DEP radon mitigation certification (how to check), and permit questions go to the township office at northcodorustwp.org.
Common questions
Is radon a problem in North Codorus Township?
Yes. PA DEP has 8,426 tests on record from the ZIP codes covering North Codorus Township, and 55.6% of them came back at or above the EPA's 4.0 pCi/L action level. 17.6% were at 20 pCi/L or more. The county-wide rate is 52.5%.
What is the average radon level in ZIP 17362?
The median of 3,003 PA DEP tests in ZIP 17362 is 5.8 pCi/L and the mean is 17.5 pCi/L. A mean that far above the median means a long tail of very high readings, topping out at 673 pCi/L.
Nearby
West Manchester Township 50.5%, Hanover 47%, Dover Township 44.2%. Share of PA DEP tests at or above 4.0 pCi/L, against 55.6% here.
Have a test result from North Codorus Township?
Send us the number and the foundation type, or call and read it out.
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