A surrogate key is nothing but an artificially created PK meaning, you should have a column or group of columns in the affected table already giving you the uniqueness you are looking for.

If you cannot find an unique identifier -column or group of columns- in the affected table I would say that there is a serious issue with your design.

Surrogate Keys are meaningless from the business perspective.
Surrogate Keys are allocating additional space in your table.
Surrogate Keys require you to create a specific process to populate them e.g.: we are adding a level of complexity.

Why would you want to face all these issues when you can easily build a PK using the actual information already sitting in your affected table?

That being said... they are here to stay. Sad, isn't it? : )