The easiest way to complete this task is via utilizing your Scav character on Interchange to loot the OLI store, as propane tanks are commonly found on the shelving in the area.
Objectives
✓
Find Propane tanks (5L) in raid
✓
Hand over the items
Task requirements
Thirsty - HoundsDone
Completion rewards
Properties
Experience10,000
RestartableNo
Kappa requiredNo
Min player level1
Lightkeeper requiredNo
Trader
SkierTrader level requirements
Skier>= 1