Radon Mitigation in Carlisle
High radon risk from Great Valley limestone and dolomite formations underlying Cumberland County. Carlisle's karst geology creates void networks that accelerate radon migration. Zone 1 classification reflects consistently elevated testing data across the county.
High Radon Risk Area
Carlisle sits in EPA Zone 1 — testing is recommended for every home regardless of age or foundation type.
Local Geology & Risk Factors
Carlisle is located in an area with Great Valley Limestone / Folded Sedimentary Belt 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: $212,400 · Median year built: 1952
- Population: 21,335
- Foundation types: Basement (most common); Stone foundation (historic district homes); Slab-on-grade (newer developments)
Cumberland County Context
Carlisle is a municipality of Cumberland County, EPA Zone 1. Zone designation is assigned at the county level, so Carlisle inherits its classification; countywide aggregate figures live on the county page.
See Cumberland County radon aggregate data →Measured Radon Data for Carlisle
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 Carlisle
Active sub-slab depressurization (ASD) systems in Carlisle typically cost $975–$2,400. 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)
- Stone foundation (historic district homes)
- Slab-on-grade (newer developments)
Systems used in the region
- Active sub-slab depressurization
- Sump pit depressurization
- Crawlspace encapsulation
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 Carlisle, Cumberland 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 risk high in Carlisle, PA?
Carlisle sits on Great Valley limestone and dolomite formations that create karst void networks — natural underground channels through which radon gas migrates rapidly into homes. Cumberland County's Zone 1 EPA classification reflects consistently elevated testing data. 47.3% of tested Carlisle-area homes exceed EPA's 4 pCi/L action level.
What does radon mitigation cost in Carlisle?
Standard ASD installations in Carlisle cost $975–$2,400. Historic district stone foundation homes may require block wall depressurization, increasing costs. Newer single-family homes in surrounding townships typically fall at the lower end of the range. Request quotes from DEP-certified Cumberland County contractors.
What's the average radon level in Carlisle?
Carlisle's DEP-recorded basement average is 9.42 pCi/L across 9,363 tests. The EPA action level for mitigation is 4.0 pCi/L, so a sizable share of Carlisle homes exceed the threshold. The highest single result in the local dataset is 350.0 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 Carlisle need to be tested for radon?
Cumberland County is EPA Zone 1 — the highest radon-potential classification — so every home in Carlisle 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 Carlisle?
Active sub-slab depressurization (ASD) systems in the Carlisle area typically cost $975–$2,400. 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 Carlisle?
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 Carlisle, 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 Carlisle radon data cover?
The Carlisle radon dataset on this page covers ZIP code 17013. These are the ZCTAs assigned to Carlisle 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 Carlisle Area School District buildings subject to SB 760?
Cumberland County is in EPA Zone 1 and is served by 9 school districts, including Carlisle Area School District. Pennsylvania Senate Bill 760, if enacted as drafted, would apply to all public school buildings in Cumberland County regardless of which district operates them. The bill remains in committee. Buildings in Zone 1 counties like Cumberland 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.
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