(1) Once again, the floor plan is identical to the last dump. The main items here are 2 acid vests and 3 grenades. You also want to make sure you nab all 12 derm patches along the way. Open the exit door and get the 2 patches directly in front of you.
(2) Turn right and blow the secret wall; just inside is a grenade.
(3) Keep going and stay to your left; blow the wall just past the pulse rifle magazine to get another grenade and then knock out the next wall, too. Keep to the left as you move and you'll find a shoulder lamp and the acid vest.
(4) Now blow the wall behind the shotshell and you will enter the main conduit of the level.
(5) Run up the unexplored stairway and back to the level entrance, grabbing all the derm patches as you move--some are hidden between or behind crates, so keep your eyes open! There are also a shotshell and some med kits in your path, if you need them, and 1 seismic charge that you want to make sure you get. If your shotgun or pulse rifle aren't topped off yet, blow the left wall just before the last flight of stairs on your way back to the entrance. If you still need grenades, crash the opposite wall (plus 3 others) to get them; there is also a shotgun and acid vest along this route, but you won't end up with all the derm patches.