Mike,
Thank you for the response and I realize that the LGIM is a great starting point that needs to be adapted. We will consider separating the Structures out into individual FC in the future as you mentioned. I am still curious though how others have incorporated tank capacity and type into the model, even if they are only for labeling. I assume that since Tank Type (Elevated,Ground) and Tank Capacity are very basic, yet extremely relevant components of a system, someone has encountered this and may want to share their experience. For now I am adding fields called "Label1" & "Label2" to preserve and use the information for cartographic reasons. Then I can also add Label information about the Production Wells, Pump Stations, and Meter Stations stored in the same FC.
Thanks!