I cannot give you advice on how best to handle your employer. The CD will appear on a normal CCH. The discharge itself may or may not be there but the arrest is extremely likely to appear. These entries can be expunged 6 months after the dismissal (completion of the program). That procedure takes about 2 months to get the Order but because of State Police backlog about 2 months more to erase the entries. Call with more information if you like.
You have no conviction record. You do have an arrest record. An expungement petition and order will isolate such records so that you may not need to disclose same in certain employment applications.