Take the Rhinostery Canteen he gives you to Giddeus to spring (K-12) or (E-12) and fill it up for a Canteen of Giddeus Water and bring it back for your reward.
Ohbiru-Dohburu is running out of the Giddeus water needed to raise Fluoro-flora. He wants you to take a Rhinostery canteen to the springs at the back off Giddeus in order to refill his supply.