Radon Mitigation in Pennsylvania
Pennsylvania is one of the highest radon risk states in the country, with a large percentage of homes testing above recommended safety levels. Radon is a naturally occurring radioactive gas that enters buildings through soil and foundation openings and cannot be detected without testing.
House Radon helps Pennsylvania homeowners, buyers, and property owners connect with experienced radon mitigation professionals who design and install effective systems to reduce radon levels and protect indoor air quality. Pennsylvania’s combination of uranium-rich geology, widespread basement construction, and older housing stock makes radon a statewide concern — not just a regional one.
If you are searching for radon mitigation in Pennsylvania, this page explains the radon risk across the state, which areas carry the greatest exposure, when mitigation is needed, and how to request a quote from a certified professional.
Is Radon a Serious Problem in Pennsylvania?
Yes. Pennsylvania is widely recognized as one of the highest radon risk states in the United States. The Pennsylvania Department of Environmental Protection (DEP) reports that approximately 40% of Pennsylvania homes tested have radon levels at or above the EPA action level of 4 pCi/L — well above the national average.
Pennsylvania’s high radon levels stem from a combination of factors:
- Uranium-rich soil and bedrock, particularly in the Reading Prong geological formation that runs through southeastern Pennsylvania
- Older housing stock with less airtight construction and more foundation entry points
- Widespread use of basements — the most common radon entry pathway
- Dense residential development in high-geology-risk areas
Pennsylvania’s radon problem is serious enough that the state has one of the most active radon programs in the country, managed by the PA DEP’s Radon Division.
Pennsylvania Counties with Elevated Radon Levels
Elevated radon levels have been documented throughout Pennsylvania. Counties with consistently high testing data include:
- Berks County — one of the highest radon counties in the nation; Reading Prong geology
- Lehigh County — Allentown area; consistently elevated levels across residential zones
- Northampton County — Bethlehem area; part of the Reading Prong formation
- Montgomery County — suburban Philadelphia; significant testing volume with high positive rate
- Bucks County — north of Philadelphia; elevated radon common in older residential stock
- Chester County — elevated levels particularly in the western and northern sections
- Lancaster County — agricultural and residential areas with frequent above-action-level readings
- York County — significant radon prevalence, especially in older housing
- Dauphin County — Harrisburg area; statewide capital region with elevated risk
- Allegheny County — Pittsburgh metro area; widespread elevated radon across diverse housing types
Even outside these high-risk counties, testing is essential. Radon levels vary street-by-street and home-by-home based on foundation type, construction age, and local soil conditions.
When Is Radon Mitigation Needed in Pennsylvania?
Radon mitigation is recommended when:
- A radon test shows levels at or above 4.0 pCi/L — the EPA action level
- Buying or selling a home — radon testing is standard in PA real estate transactions
- Finishing a basement or converting lower-level space to occupied use
- Upgrading or repairing an existing radon system
- Living in an older home with no testing history
- Improving long-term indoor air quality as a health priority
Many Pennsylvania homeowners choose mitigation at levels between 2–4 pCi/L — particularly in the Reading Prong region — given the elevated baseline risk in the area. For information on pre-mitigation testing, see our radon testing services page.
How Radon Mitigation Works in Pennsylvania Homes
The most common and effective technique used in Pennsylvania is sub-slab depressurization (SSD). The system works by:
- Drilling one or more suction points through the basement floor slab
- Routing PVC vent piping through the home or along the exterior wall to the roofline
- Installing a continuously operating radon fan that draws gas from beneath the slab
- Venting radon safely above the roofline where it disperses outdoors
- Sealing visible foundation cracks, floor drains, and sump pit covers to reduce entry points
Pennsylvania’s dense basement housing stock makes SSD systems particularly well-suited to the state’s residential profile. Most systems reduce indoor radon by 80–99% when properly installed.
Property Types Served in Pennsylvania
Radon mitigation in Pennsylvania is available for all property types:
- Single-family homes with basements, slabs, or crawl spaces
- Townhomes and row homes — common in Philadelphia and Pittsburgh
- Older homes with stone or block foundations
- New construction — radon-resistant systems during the build
- Multi-family and apartment buildings
- Commercial, school, and public buildings
Older Pennsylvania homes — particularly those with stone block foundations common in the southeast — may require specialized approaches. A certified contractor will assess the foundation and radon entry points before recommending a system design.
How Much Does Radon Mitigation Cost in Pennsylvania?
Radon mitigation costs in Pennsylvania vary based on system design, foundation type, and the complexity of the installation. Typical pricing:
| Property Type | Typical Cost Range |
|---|---|
| Residential home (basement) | $800 – $2,500 |
| Older stone or block foundation | $1,500 – $3,500 |
| Crawl space system | $1,200 – $3,000 |
| New construction installation | $500 – $1,500 |
| Fan replacement or system repair | $250 – $700 |
House Radon helps connect you with Pennsylvania-based professionals who provide accurate quotes before any work begins. Costs vary by contractor and region within the state.
Pennsylvania Radon Certification and State Program
Pennsylvania requires radon testing and mitigation professionals to be certified through the state’s own program, administered by the Pennsylvania Department of Environmental Protection (PA DEP) Radon Division. This is one of the most stringent state radon programs in the country.
Always verify that your contractor holds a current PA DEP radon mitigation certification. The PA DEP maintains a public database of certified professionals. Certified contractors follow state-approved mitigation standards and carry the required insurance and documentation.
Frequently Asked Questions — Radon Mitigation in Pennsylvania
Why is Pennsylvania’s radon level so high?
Pennsylvania sits atop the Reading Prong — a geological formation of uranium-rich granite and gneiss that runs through the southeastern part of the state and extends into New Jersey and New York. This bedrock releases radon gas that migrates upward through soil and enters buildings through foundations. Combined with a high prevalence of basement construction and older homes, Pennsylvania consistently reports some of the highest indoor radon levels in the country.
Is radon testing required to sell a home in Pennsylvania?
Pennsylvania does not legally require radon testing to sell a home, but the PA DEP strongly recommends it and many buyers request it as part of a home inspection contingency. Real estate radon tests are conducted by PA DEP-certified testers and typically use continuous electronic monitors placed in the lowest livable level for 48 hours under closed-house conditions.
Does Pennsylvania have a certified radon contractor program?
Yes. Pennsylvania is one of a small number of states with its own mandatory radon certification program. Both radon testing professionals and radon mitigation contractors must hold PA DEP certification to legally perform radon services in the state. When hiring a contractor, request their PA DEP certification number and verify it through the DEP’s public online directory.
Can an older stone foundation home in Pennsylvania be mitigated?
Yes, though it may require a modified approach. Older stone or block foundations present more complex entry pathways than modern poured concrete slabs. Mitigation may involve a combination of sub-membrane depressurization, block wall depressurization, and extensive sealing. Costs are typically higher than for standard basement systems. An on-site assessment by a PA DEP-certified contractor is essential for older properties.
How soon will I see results after radon mitigation in Pennsylvania?
Post-mitigation testing can begin 24–48 hours after installation. Short-term tests return results in 2–7 days. Most homeowners see radon levels drop significantly — often by 80–99% — within the first post-mitigation test. The PA DEP recommends a follow-up long-term test 30–90 days after installation to establish a verified baseline.
Get a Free Radon Mitigation Quote in Pennsylvania
If your Pennsylvania home has elevated radon levels — or if you have never tested — professional mitigation from a PA DEP-certified contractor is the right next step. Fill out the form below to be connected with a qualified professional in your area.
