Air first, then water if on a well
Test the air. If it is elevated and you are on a private well, test the water before assuming sub-slab work alone will solve it.
York County, Pennsylvania
Radon guidance for Stewartstown, in the southern part of York County.
Call (717) 555-0143Stewartstown lies in southern York County, in an area of smaller boroughs and surrounding rural property. Housing includes an older borough core alongside newer development on what was previously farmland, and rural properties here are frequently on private wells.
For properties outside the borough's water service, the standard advice applies: test the air first, and if the result is elevated and the property is on a well, test the water as well. Waterborne radon is a genuinely separate problem with a separate solution, and diagnosing it after a mitigation system has already been installed and underperformed is an expensive way to learn that.

Test the air. If it is elevated and you are on a private well, test the water before assuming sub-slab work alone will solve it.
Sub-slab depressurization works the same on a rural property as anywhere else. Lot size does not change the system design.
Distance from town changes nothing about Pennsylvania's requirements. Any firm quoting testing or mitigation here should appear on the DEP Radon Division's certified list.
If the air was mitigated and the well water was treated, confirm both. One retest covering one pathway leaves the other unverified.
Independent guidance on radon testing, mitigation costs and DEP-certified contractors for homeowners in Stewartstown and the surrounding parts of York County.
Ask about a test result, what a Stewartstown mitigation quote should include, or how to check a contractor’s DEP certification.