Radon in Adams County, PA: Gettysburg Results and Costs

Close to half of basement radon tests in Adams County come back high. The 13 ZIP codes centered in the county with at least 30 basement tests show 6,405 of 14,835 tests (43.2%) at or above 4 pCi/L in PA DEP data, by our count through July 2026.

Counting all floors, the DEP set has 22,270 Adams County tests with 38.2% at or above the action level. EPA's 1993 map puts Adams in Zone 1, and all 14 Adams County ZIP areas in the Census Bureau file are in Zone 1 counties.

A standard system for an Adams County basement runs $1,200 to $2,000 in HomeGuide's Feb 2026 survey, and the county's many crawlspace and stone-foundation farmhouses add other options.

Licensing and permits

Certification: Pennsylvania DEP certifies radon testers and mitigators, and paid work in Adams County requires it (25 Pa. Code Chapter 240).

Historic properties: inside the Gettysburg borough historic district, exterior changes such as a visible vent pipe can draw review from the borough; ask your installer to plan the route before signing.

Permits: townships and boroughs handle Uniform Construction Code permits locally or through an inspection agency. HomeGuide puts radon permits at $25 to $150 where they apply.

Records: request the DEP-reported post-mitigation result for your files.

Local conditions

Most of the county lies in the Gettysburg Basin, red shale and sandstone with ridges of hard diabase, and the western edge climbs onto South Mountain's older volcanic and quartzite rock near Fairfield and Cashtown. Fractured shale and diabase can both carry soil gas into basements.

DEP basement data by ZIP: Gettysburg's 17325 was 39.1% at or above 4 pCi/L across 5,628 tests; Littlestown's 17340, south near the Maryland line, 52.6% across 2,101; Fairfield's 17320 43.7% across 1,600; New Oxford's 17350 42.6% across 1,203 (PA DEP data, our count).

Orrtanna's 17353, on the slopes toward South Mountain, reached 55.7% across 555 tests, while East Berlin's 17316 near the York County line was 37.9% across 1,342 (PA DEP data).

The fruit belt north and west of Gettysburg, around Biglerville, Arendtsville and Aspers, mixes century-old farmhouses with newer homes built on former orchard ground. Old cellars there were dug into weathered shale and diabase and were never meant to be airtight, which is why sealing often comes before suction.

What drives local prices

Crawlspaces: farmhouses and additions over dirt crawlspaces often need a sealed membrane with suction under it, which EPA's 2010 guide priced at $1,000 to $2,500 (2010 dollars).
Stone foundations: fieldstone basements in older Gettysburg and New Oxford homes may need sealing before sub-slab suction, which HomeGuide's published survey prices at $1,200 to $2,000.
Mixed foundations: a basement under the original house and a crawlspace under a wing can mean two suction areas, an est. ×1.5 in our calculator.
Permit $25 to $150 and professional retest $125 to $400 (HomeGuide).
Pipe route in the historic district: an interior or attic route to keep the pipe out of sight is an est. ×1.15.

Common jobs

Sub-slab systems in newer homes around Gettysburg, Hanover's western edge and Littlestown.
Crawlspace membrane systems under farmhouse additions.
Combined basement and crawlspace systems in older houses.
Tests for orchard-country farm sales around Biglerville and Aspers.

From test to fixed, and where we cover

Step 1: test the lowest lived-in level. Step 2: at 4 pCi/L or above, request two bids from DEP-certified mitigators.

Step 3: check each bid against the calculator. Step 4: retest after the system runs at least 24 hours.

We take requests from Gettysburg, Littlestown, New Oxford, McSherrystown, Biglerville, Fairfield, East Berlin and Bonneauville, along US 15, US 30 and Route 94.

Communities: Gettysburg, Littlestown, New Oxford, McSherrystown, Biglerville, Fairfield, East Berlin, Bonneauville

Before you sign

Take the time to compare bids; EPA treats radon as a long-term exposure (EPA Citizen's Guide). For an older house, ask the mitigator to inspect the basement and any crawlspace before quoting.

Questions about Adams County

Is radon a problem in Gettysburg?

In PA DEP data, 39.1% of basement tests in ZIP 17325 read 4 pCi/L or higher, and the county is EPA Zone 1. Test your home.

Do crawlspace homes in Adams County need a different system?

Usually a sealed membrane with suction underneath; EPA's 2010 guide priced it at $1,000 to $2,500 in 2010 dollars.

Can I put a radon pipe on a historic house?

Often yes, but plan the route; in the Gettysburg historic district an interior route may be preferred.

Who can install radon systems in Adams County?

DEP-certified mitigators only, under 25 Pa. Code Chapter 240.

Sources

Nearby counties

Rules and fees change; confirm with the state radon office. Price your own system with the radon mitigation cost calculator, read the radon mitigation cost guide, or check any ZIP with the radon levels by ZIP tool.