I had a job in my 20s and the partying was the norm. Also the hung over at work was normal too. I tried to sober up back then, but was unable to do so. I can't blame it on the place though because I know today it wouldn't prevent me from sobering up now. I am now ready to do the necessary work to stay sober and back then I was not.
If you can't switch jobs then do whatever you need to in order to hang on to your sober lifestyle. I agree that seeing and being in that environment now would help energize my determination to remain sober. Those people I worked with 20 years ago aren't drinking now and if they are then they are fighting the same battle. A body cannot withstand that kind of lifestyle for long.