Radon Mitigation in Grantley, PA
58.8% of 6,783 basement radon tests in ZIP 17403, which covers Grantley, came back at or above 4.0 pCi/L.
Grantley Radon Test Results
Grantley is in ZIP 17403, the second-largest York ZIP code for radon tests, with 6,783 on file. Its numbers run above the county: 58.8% of tests came back at or above 4.0 pCi/L, against 56.4% for York County, and the median is 5.3 pCi/L against 4.9. That puts 17403 close to 17402, which covers East York (59.7%), and above 17404, which covers West York (55.1%).
DEP files tests with a York mailing address by ZIP code, not by neighborhood, so these figures cover all of ZIP 17403, including Grantley and the streets around it. These are tests reported to DEP, not a random sample of homes.
| Area | Basement tests | Tests ≥ 4.0 | % ≥ 4.0 | Median (pCi/L) |
|---|---|---|---|---|
| ZIP 17403 (Grantley) | 6,783 | 3,986 | 58.8% | 5.3 |
| All York city ZIPs | 28,382 | 16,319 | 57.5% | n/a |
| York County | 82,215 | 46,330 | 56.4% | 4.9 |
Source: Pennsylvania DEP, Radon Test Results / Radon Mitigation System records (data.pa.gov). Retrieved October 21, 2026. Tests reported to DEP by certified labs and testers, not a random sample of homes.
What Radon Mitigation Costs in Grantley
DEP mitigation records are not broken out by ZIP code, so the best local guide is the county figure. Across York County, the median cost of a radon mitigation system was $1,150, based on 749 systems with a post-mitigation test from 2024 to 2026.
By system type, a standard sub-slab system had a county median cost of $1,175 (599 systems), and activating an existing passive pipe $775 (141 systems). 50.9% of county jobs cost between $935 and $1,320. We confirm your price in writing after a free inspection.
Basement vs First Floor
Radon is usually highest at the lowest level of a house. In York County, basement tests have a median of 4.9 pCi/L and first-floor tests 2.1 pCi/L, with 33.4% of first-floor tests at or above 4.0. ZIP 17403's basement median of 5.3 pCi/L is above the county's, so a first-floor test alone can understate the risk. Test the lowest level you use.
| York County test level | Tests | Median (pCi/L) | % ≥ 4.0 |
|---|---|---|---|
| Basement | 82,215 | 4.9 | 56.4% |
| First floor | 10,703 | 2.1 | 33.4% |
Source: Pennsylvania DEP, Radon Test Results / Radon Mitigation System records (data.pa.gov). Retrieved October 21, 2026. Tests reported to DEP by certified labs and testers, not a random sample of homes.
How a Radon System Works in Grantley Homes
Most systems in York County are active sub-slab depressurization. Our crew seals the sump and major cracks, cuts a suction point through the basement floor, and runs a sealed pipe to a fan mounted outside the living space. The fan keeps the soil under the house at lower pressure than the rooms above, so radon is drawn into the pipe and vented above the roofline instead of seeping indoors. A gauge on the pipe shows the fan is pulling. Across the county, the median reading was 12.0 pCi/L before mitigation and 1.0 pCi/L after, and 97.5% of systems tested below 4.0 pCi/L afterward. In Grantley, every system we install gets a follow-up test so you see your own before and after.
Check Any Radon Mitigator's Certification in Grantley
Pennsylvania requires anyone who tests for radon or installs a mitigation system for hire to be certified by the Department of Environmental Protection. We hold that certification, and we welcome the same checks. Before you hire anyone in Grantley, including us:
- Ask for the DEP certification number of the person and the firm, then check it in the PA DEP Radon Services Directory (opens in a new tab), which DEP updates monthly by county.
- Get the scope and price in writing.
- Ask for proof of liability insurance and a Pennsylvania home improvement contractor registration.
- Ask for a follow-up test after the fan runs.
How We Handle Radon Mitigation in Grantley
We are a PA DEP-certified radon mitigation firm. Our own crew does every job.
- 1 Step 1
You send your result
Your ZIP code and radon result, if you have one. The estimate is free.
- 2 Step 2
We inspect and quote
We check the foundation and put the design and price in writing.
- 3 Step 3
Our crew installs
Our certified crew seals the slab, runs the pipe and mounts the fan.
- 4 Step 4
We retest
A follow-up test puts your new level on paper.
Radon Services We Provide in Grantley
Our PA DEP-certified crew tests, installs, repairs and services radon systems in Grantley homes. Pick a service to see the work and the price range.
Radon FAQs for Grantley
3,986 of 6,783 basement tests in ZIP 17403 (58.8%) were at or above 4.0 pCi/L.
A little above the city average. 58.8% of tests in 17403 reached 4.0 pCi/L, against 57.5% across all York city ZIP codes.
DEP cost data is county-wide: a median of $1,150 from 2024 to 2026, with 50.9% of jobs between $935 and $1,320.
No. It covers every test DEP files under ZIP 17403. These are tests reported to DEP, not a random sample of homes.
Sources
- Pennsylvania DEP, Radon Test Results, September 1986 to Current (data.pa.gov)
- Pennsylvania DEP, Radon Mitigation System Year, 1987 to Current (data.pa.gov)
- U.S. EPA, Health Risk of Radon
- U.S. EPA, Consumer's Guide to Radon Reduction
- Pennsylvania Code, 25 Pa. Code Chapter 240, Radon Certification
- Pennsylvania DEP, Radon Services Directory (certified testers, mitigators and labs by county)
Data retrieved October 21, 2026. Links, dates and methods for every source are on our sources and resources page.