There are no official drinking fountains in DME. You can buy bottled water from vending machines at 90 rubles a pop, which on an 8hrs layover is a bit much.
The toilets have faucets but they don’t all have a cold water faucet. I managed to find one in the men’s toilet on the 3rd floor, and I filled my water bottle there. I’m still alive.
#plasticfree
Jonas V