David Dempster » Radon Measurements & Mitigation Services Go back to directory. David Dempster Square One Home Inspections Work 122 Manchester Ct. Mankato MN 56001 work Work Phone: 507-508-3891work Work Email: david@squareonehomeinspections.comINTERNET Categories: Affiliates, Home Inspector, Radon Measurements & Mitigation Services Updated 9 months ago.