Travel to the Dwarven District in Stormwind and find an engineer who can help.
The supplies you found point to a massive industrial operation somewhere in the Deadmines. There's no question that this is the source of the toxins plaguing the farmland of Westfall. We need to stop it, quickly.
Whatever's down there will be difficult to destroy. Go to the Dwarven District of Stormwind, and find an engineer who can supply us with some explosives.
