OS X Server - Reset all POSIX and ACLs on new file share

I've just set up a new mini running OS X Yosemite/Server 4, and am using a Drobo 5D for file storage. All of the files on the Drobo have been copied from an old Xserve setup and various external drives and at least one other Mac's user folder.

I have my own admin account on the mini, then a small handful of users with local accounts on the mini (added through the Users panel) in a single Group which I've given access to the fileshare. Eventually there will be two Groups, one for administrative stuff that will be in a separate folder that the other users can't access. So, fairly simple.

Is there a proper way in Server to reset all ownership and permissions for the entire fileshare? I'd like to start with the cleanest slate possible. I'm comfortable with the usual simple Linux chmod/chown commands but completely unfamiliar with the ACL and umask and what not, but am not afraid to cut and paste into Terminal. :) Basically I'd want to be sure to wipe out any old ownerships or other stuff from other machines, and make sure everything is set up so we don't run into any problems down the line with new files or modifying old ones.

Thanks in advance!