GroundRoster
Home › Maryland › Keymar › John O'Connor

John O'ConnorLicensed

Licensed radon professional based in Keymar, Carroll County, MD

License number3361
License typeRadon Measurement Professional
License statusActive, PA DEP certified
Based inKeymar, Carroll County, Maryland

"Based in" is the city and county of the address on the business's license record. That can be a mailing address; it doesn't tell you where the business works.

Get free quotes

How to verify this license

We publish the license details exactly as they appear in the official licensing records of the agency that issued the license; we do not vouch for the business itself. Before hiring, look up license #3361 directly with the agency that issued it, confirm it is still active, and ask for a current certificate of insurance.

Checked against PA DEP radon services directory, last checked 2026-11-02. See the issuing agency.

For the business owner: Own John O'Connor? Claim this listing

Other radon professionals based in Carroll County

Jerry PickholtzLicensed

Radon · Tester
Based in Westminster, MD · License #3267

Erin E. DittmanLicensed

Radon · Tester
Based in Westminister, MD · License #RT000937

See every listing based in Keymar.