Shrewsbury sits on the Wissahickon schist and gneiss of southern York County, a few miles north of the Maryland line, and this is some of the highest-radon ground in Pennsylvania. Fractured metamorphic rock gives soil gas direct pathways to the surface, and DEP test data for the 17361 ZIP code shows average basement readings well above the state average, with many homes in the 10–30 pCi/L range and outliers far higher. If you are buying or selling in Shrewsbury, expect radon to come up during the inspection period.
The borough is mostly 1900s–1950s homes on stone and block foundations along Main Street and Forrest Avenue; the township has grown quickly since the 1990s with developments off Mount Airy Road, Constitution Avenue and the Susquehanna Trail on the way to New Freedom and Glen Rock. The uplands soil here is tight, so we carry high-static fans on every Shrewsbury visit and frequently install two suction points to reach the full slab. Older stone-foundation homes may also need a crawl space membrane system tied into the main fan, and many rural properties on wells should add a water radon test.
Around Shrewsbury
We regularly work near:
- 📍Shrewsbury Commons
- 📍I-83 Exit 4
- 📍Susquehanna Trail
- 📍Shrewsbury Township Park
- 📍Main Street Shrewsbury
Radon Mitigation in Shrewsbury — Local Notes
- •Tight schist soils — high-static fans and two-point systems are common here.
- •Private wells on the ridges toward Stewartstown may carry waterborne radon.