I do not work for UMC, but in the course of one of my jobs I interact with the ER staff regularly. I can give you a little insight from that perspective. I can not give input on any other units.
I will say the culture and overall lack of professionalism there is unlike anything I have ever seen. There has been a lot of staff turnover lately, so maybe that will change. I know they are VERY busy with low acuity patients that come in daily, or even multiple times a day.
I am hesitant to say too much on a public forum. I STRONGLY suggest you take a trip there and speak to current employees for their perspective. Personally, that would be the last hospital in DC I would work for.