This may also be considered functionality.
Think through the life cycle of a data set. This will be slighty different than a data system. If a new data set, it would not be unusual to think launch / growth / retirement (not dead, data is still available just not expanding and possibly access is contracting) / archived / dead and buried.

Recomend the “Suggest New Data Source” form add a selection box to add / modify / or delete. Also either modify title of this link or add a new link title modify / delete data source (and go to same multipurpuse form)
There are other variations to accomplish these activities, the above is just the cheapest to implement today, not necessarily the best for either the end user or EPA.