DEP-Certified Network

Radon Mitigation in Chambersburg

High radon potential. Cumberland Valley limestone-dolomite bedrock with extensive solution cavities produces direct soil-gas pathways into homes across Franklin County.

10.06 pCi/L
Average basement radon (measured)
$900–$2,050
Typical mitigation cost
1–2 Days
Typical installation window
EPA Zone 1
Franklin County

High Radon Risk Area

Chambersburg sits in EPA Zone 1 — testing is recommended for every home regardless of age or foundation type.

EPA Zone: 14,153 basement tests on record

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

Basement average
10.06 pCi/L
4,153 tests
First-floor average
6.49 pCi/L
729 tests
Highest reading
403.7 pCi/L
Single-home peak
ZIP coverage
17201, 17202

This unusually high reading may reflect a source data anomaly or a single-home outlier; individual home results vary widely.

Source: PA DEP RadonZip Tool, January 1990 – December 2025 · Updated 2026-05-20

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

DEP Certification Required

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.

Seller Disclosure

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.

Verify Certification

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 Directory

The 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. EPA Zone 1 classification reflects approximately 50% of tested Franklin County homes exceeding 4.0 pCi/L.

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's the average radon level in Chambersburg?

Chambersburg's DEP-recorded basement average is 10.06 pCi/L across 4,153 tests. The EPA action level for mitigation is 4.0 pCi/L, so a sizable share of Chambersburg homes exceed the threshold. The highest single result in the local dataset is 403.7 pCi/L; this unusually high reading may reflect a source data anomaly or a single-home outlier — individual home results vary widely.

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 used for the PA DEP RadonZip Tool aggregation. Neighboring ZIP codes belong to adjacent municipalities and appear on their own PA Radon Hub pages.

Are Chambersburg Area School District buildings subject to SB 760?

Franklin County is in EPA Zone 1 and is served by 6 school districts, including Chambersburg Area School District. Pennsylvania Senate Bill 760, if enacted as drafted, would apply to all public school buildings in Franklin County regardless of which district operates them. The bill remains in committee. Buildings in Zone 1 counties like Franklin County would be highest priority under the proposed framework. If SB 760 is enacted, mitigation timelines, thresholds, and qualifying buildings would be set by the final bill text and any subsequent DEP implementing regulations. PA Radon Hub tracks this legislation; specific deadlines remain pending.

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.

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PA Radon Hub is an independent informational resource and is not a radon service provider. Verify contractor certification at dep.pa.gov before hiring.

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