If you need a quest item then you ought to be able to get it from the correct npc by right clicking on him and picking the mouth icon. This will bring up the quest dialog window where the dialog choice will be clearly marked as to the particular quest. If it is true that jomed has a bottle for this quest and no dialog for requesting one shows up in his quest dialog window then it is perhaps because you first need to talk to whichever npc will give you the water but does not have the bottle to put it in, i.e. you might be missing a step required to complete the quest.
I would wander around in east hydlaa asking npc's. There might be someone likely to know about PURE water on that map.
