Thanks for the script. I am kind of new to T-SQL could you give me a quick summary of what this does?

I should mention that the records with the duplicate Parcel IDs are really unique records, in some way. There are about 14 columns in a record and 3 of which have different values in them. So, only the parcel ids are the same, but the rest of the values would be different. However, the application uses parcel ids to update the records.