This is the sole water fountain in Dublin airport"s int'l departure wing. Having had to empty all drinking vessels to get through security, clearly the airport expects you to buy a new water bottle from the one monopoly water vendor. Greed and #securitytheater are the main reasons air travel is eye-wateringly unsustainable and generally unpleasant.
Alternatively, you can freeze your bottled water in advance, as solids don't have a volume limit.
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