Legality of VERY tall back deck

[Brandon G.]

Our new to us, non owner occupied (first property) duplex has two very, very tall decks behind each unit that goes down to a creek.  The units are on a steep hill.  I may be off, but I would say the rear decks are 30 feet or so.  The units and decks have been inspected by a licensed inspector previous to the purchase of the property.  Is there anything I could or should add in the contract to help protect myself in the event of someone falling off the deck due to their negligence?

Thanks,

Brandon