Radon Testing & Mitigation in Chambersburg, PA
High radon potential. Cumberland Valley limestone-dolomite bedrock with extensive solution cavities produces direct soil-gas pathways into homes across Franklin County.
High Radon Risk Area
Chambersburg sits in EPA Zone 1 — testing is recommended for every home regardless of age or foundation type.
Radon Testing in Chambersburg
In Chambersburg-area ZIP codes, 59% of 8,967 basement tests reported to PA DEP measured 4.0 pCi/L or higher, with a median of 5.3 pCi/L. Readings differ from house to house, so each home needs its own test. Start with a short-term test of 48–96 hours on the lowest lived-in level. A long-term test of 90 days or more averages out seasonal swings.
A result at or above EPA's 4.0 pCi/L action level calls for a confirming test or mitigation. Retest after a mitigation system goes in, and at least every two years from then on. Pennsylvania requires DEP certification for anyone who tests as a paid service; you may test your own home with a kit from a DEP-certified laboratory. For a home sale, read the Pennsylvania real estate radon testing guide.
Local Geology & Risk Factors
Chambersburg is located in an area with Great Valley / Cumberland Valley Limestone-Dolomite geology, which contributes to elevated radon levels. The Pennsylvania DEP identifies this region as having significant radon potential due to uranium-bearing rock formations.
Testing is essential because radon levels can vary significantly between neighboring homes based on construction, soil permeability, and ventilation.
See Pennsylvania radon levels and EPA radon zone classifications →
Quick Facts
- Median home value: $196,200 · Median year built: 1963
- Population: 22,051
- Foundation types: Basement (most common); Crawlspace (moderate); Slab-on-grade (varies)
Franklin County Context
Chambersburg is a municipality of Franklin County, EPA Zone 1. Zone designation is assigned at the county level, so Chambersburg inherits its classification; countywide aggregate figures live on the county page.
See Franklin County radon aggregate data →Measured Radon Data for Chambersburg
These figures cover every test whose ZIP code is listed above. ZIP codes do not follow municipal lines, so the figures describe Chambersburg-area ZIP codes, not the municipal boundary of Chambersburg. They count tests, not homes.
Source: PA Department of Environmental Protection, Radon Test Results, data.pa.gov. Tests through July 2026. Retrieved September 29, 2026.
Ready to move forward? Talk to a DEP-certified pro.
Radon Mitigation Cost in Chambersburg
Active sub-slab depressurization (ASD) systems in Chambersburg typically cost $900–$2,050. Standard basement installs on modern poured concrete fall at the lower end; historic foundations, block-wall depressurization, multi-point suction, and crawlspace encapsulation push costs higher.
Foundations covered locally
- Basement (most common)
- Crawlspace (moderate)
- Slab-on-grade (varies)
Systems used in the region
- Active sub-slab depressurization
- Sump pit depressurization
- Passive soil depressurization
Certification & Compliance
All Pennsylvania radon testing and mitigation professionals must hold active PA DEP certification. Ask any contractor for their certification number and verify it before signing.
Pennsylvania's Real Estate Seller Disclosure Law (68 Pa.C.S. §§ 7301–7315) requires sellers to disclose known material defects to buyers under § 7303; the mandated disclosure form records radon under § 7304(b)(14). Sellers who have never tested are not compelled to test — § 7308 imposes no affirmative duty to investigate — but pre-listing testing is standard practice across most PA markets.
Under 25 Pa. Code § 240 — the Pennsylvania chapter governing radon certification — every radon service provider working in the Commonwealth must hold current DEP certification. Verify the contractor's status via the DEP Radon Services Directory before hiring.
Verify Contractor Certification — PA DEP Official Directory for Chambersburg, Franklin County
View PA DEP Certified Contractor DirectoryThe PA Department of Environmental Protection maintains the official list of certified radon testers and mitigators, sorted by county and updated monthly. Always verify certification before hiring any contractor.
Directory resource provided by PA DEP Bureau of Radiation Protection, Radon Division.
Frequently Asked Questions
Why is radon a concern in Chambersburg, PA?
Chambersburg sits in the Great Valley over Cumberland Valley limestone and dolomite. Solution cavities and karst features in the carbonate bedrock create direct soil-gas pathways into basements. Franklin County is EPA Zone 1. 59% of the 20,716 basement tests reported to PA DEP from Franklin County measured 4.0 pCi/L or higher.
What does radon mitigation cost in Franklin County?
Most Franklin County mitigation systems run $900–$2,050 installed. Active sub-slab depressurization works well in modern slab-on-grade construction; older fieldstone-foundation homes around downtown Chambersburg often require additional sealing of karst-related foundation cracks.
Does karst topography affect radon risk in the Cumberland Valley?
Yes. The Cumberland Valley's karst features — sinkholes, caves, and dissolution channels — create direct conduits for radon-rich soil gas to migrate from the underlying carbonate bedrock into homes. Properties with documented sinkhole activity warrant long-term radon testing.
What share of radon tests in Chambersburg-area ZIP codes are at or above the EPA action level?
59% of the 8,967 basement tests reported to PA DEP from Chambersburg-area ZIP codes measured 4.0 pCi/L or higher, 22 points above the 37% statewide share. The median result is 5.3 pCi/L. Of 1,381 first-floor tests, 45% measured 4.0 pCi/L or higher. The figures cover the ZIP codes listed on this page, not the municipal boundary, and they count tests, not homes.
Do homes in Chambersburg need to be tested for radon?
Franklin County is EPA Zone 1 — the highest radon-potential classification — so every home in Chambersburg should be tested regardless of age, foundation type, or neighborhood. Short-term charcoal or continuous monitor tests take 48–96 hours and cost $15–$50; long-term alpha-track tests run 90 days and better represent annual averages. If the result meets or exceeds 4.0 pCi/L, mitigation by a DEP-certified professional is recommended.
How much does radon mitigation cost in Chambersburg?
Active sub-slab depressurization (ASD) systems in the Chambersburg area typically cost $900–$2,050. Standard basement installations on modern poured-concrete foundations fall at the lower end; historic foundations, block-wall depressurization, multi-point suction, and crawlspace encapsulation push costs toward the upper end. All work must be performed by a DEP-certified mitigation professional under 25 Pa. Code § 240.
Is radon disclosure required when selling a home in Chambersburg?
Pennsylvania's Real Estate Seller Disclosure Law (68 Pa.C.S. §§ 7301–7315) requires residential sellers to disclose known material defects to buyers (§ 7303). The state-mandated disclosure form covers 'presence of hazardous substances' at § 7304(b)(14) — where any known elevated radon test result or existing mitigation system is recorded. Sellers who have never tested are not required to test: § 7308 imposes no affirmative duty to investigate. In Chambersburg, the practical reality is that most buyers request radon testing during the inspection contingency period. Sellers who test and mitigate before listing eliminate the most common contract contingency and preserve negotiating position.
Which ZIP codes does the Chambersburg radon data cover?
The Chambersburg radon dataset on this page covers ZIP codes 17201 and 17202. These are the ZCTAs assigned to Chambersburg in the Census 2020 ZCTA-to-Place relationship file, and the page counts every test in the PA DEP record on data.pa.gov that carries one of them. A ZIP code can reach into a neighboring municipality, so the figures describe these ZIP codes rather than Chambersburg's municipal boundary.
Connect with a DEP-Certified Radon Pro in Chambersburg
Submit your request and we will connect you with a DEP-certified professional serving Franklin County.
(717) 461-2427Connect with a DEP-certified radon pro