Are homeowners required to remove existing oil tanks after converting from oil to gas?

A tank that is no longer in use must be removed and properly disposed of within 24 months in Massachusetts. A permit from the fire department is required and the tank must be taken to a licensed recycling facility.  For more information please see the Massachusetts Board of Fire Prevention Regulation 527 CMR 9. In New Hampshire the State Fire Marshall adopts NFPA 31, which requires removal of any tank that is permanently disconnected. Fuel, supply, and vent lines must also be removed if no longer in use.