Mission: Eternal Flame

Objectives
Scout Knowles at the Ember Spear Tower has recommended that you use the Ever-Burning Torches to destroy the four Plague Tanks surrounding Halgrind.
 * Southwest Plague Tank Destroyed
 * Northwest Plague Tank Destroyed
 * Northeast Plague Tank Destroyed
 * Southeast Plague Tank Destroyed

Description
The Forsaken are up to no good and from what I can tell, those plague tanks of sludge are a big part of it.

If I may suggest, , we should probably destroy them before they can get any more use out of the things. I took the liberty of preparing a bundle of torches from the Ember Clutch. These things have been burning for days!

Here, I'm sure you can put them to better use than I in destroying those tanks.

Rewards
You will also receive:

Progress
It's hard to tell from all the way over here exactly what's happening down there. Did you manage to put those plague tanks to the torch?

Completion
Nice!

But what's this about the stuff you found inside those tanks? Are you saying that the Forsaken are spraying a plague upon the vrykul down there?