Right now almost everything is shut airside, so we continue to bypass the Duty-Free emporium and use the staff shortcut to get to the main departure area. The one exception is the fairly large Boots store, which is serving own-label water for 1.15 per litre or £2 for two bottles. You can't use the taps in the WC since it's a one warm water spout, which can't be adjusted and I can't believe that is palatable.

However!

I have a solution for those who justly crave the tasty waters emanating the Catcleugh Reservoir, probably the finest public hydration in the world. It does help if you have long arms. There are two closed bar areas which are set up in such a way that by leaning over the counter one can reach the taps, and the sinks are deep enough for most bottles. Here is what you are looking for, and the arrows indicate the location. The Bar 11 is particularly easy to use since while the bar is not operating, it is clearly being used as a seating area given the way that the airport has roped off the main bar areas. There aren't a lot of seats in the public area so I don't think they are minding people using Bar 11, indeed there are plenty of people taking advantage of the mixed seating available there.


The above show the Cabin Bar and Bar 11. Arrows show where to look.


For the Cabin Bar the taps are on the left of the bar frontage, by the pillar.


You want the taps on the left, there's a strong water pressure on these taps.


And this is from Bar 11. Again the cold water is on the left.

[Note, while this post has a claim to be Peak Flyertalk, the usefulness may be short-lived when the airport opens up more fully].